Process for producing l-glufosinate from a diol or diol derivative

Abstract

A process for making L-glufosinate, the process comprising the following steps: a) reacting a compound according to formula (I), (I), wherein R1 is hydrogen, (C1-C12)-alkyl, (C1-C12)-haloalkyl, (C6-C10)-aryl, (C6-C10)-haloaryl, (C7-C10)-aralkyl, (C7-C10)-haloaralkyl, (C4-C10)-cycloalkyl, or (C4-C10)-halocycloalkyl, with a compound according to formula (II), (II), wherein R2 and R3 are independently from each other (C1-C8)-acyloxy, (C1-C8)-alkoxy or hydroxy, or R2 and R3 form together an epoxide group or an ethylene carbonate group, and optional subsequent acidic treatment to form a diol according to formula (III), (III), b) Oxidizing the diol according to formula (III) to form 2-oxo-4-(hydroxy(methyl)phosphinoyl)butyric acid (PPO); and c) aminating the PPO to L-glufosinate.

Description

[0001] Process for Producing L-Glufosinate from a Diol or Diol Derivative

[0002] Technical Field of the Invention

[0003] The present invention relates to a process for producing L-glufosinate starting from a diol or diol derivative. Furthermore, the present invention relates to a composition of a diol and / or a ketone, optionally 2-oxo-4-(hydroxy(methyl)phosphinoyl)butyric acid (PPO), and L- glufosinate. Moreover, the present invention relates to a method of selectively controlling weeds in an area comprising a crop of planted seeds or crops that are resistant to glufosinate using a composition of a diol and / or a ketone, optionally 2-oxo-4- (hydroxy(methyl)phosphinoyl)butyric acid (PPO), and L-glufosinate.

[0004] Background of the Invention

[0005] The herbicide glufosinate is a non-selective, foliarly applied herbicide considered to be one of the safest herbicides from a toxicological or environmental standpoint. Current commercial chemical synthesis methods for glufosinate yield a racemic mixture of L- and D-glufosinate (Duke et al. 2010 Toxins 2:1943-1962). However, L-glufosinate (also known as phosphinothricin or (S)-2-amino-4-(hydroxy(methyl)phosphonoyl)butanoic acid) is much more potent than D-glufosinate (Ruhland et al. (2002) Environ. Biosafety Res. 1:29-37). Therefore, methods are needed to produce only or primarily the active, L-glufosinate form. WO 2017 / 151573 Al describes a method for producing L-glufosinate from D-glufosinate using 2-oxo-4-(hydroxy(methyl)phosphinoyl)butyric acid (PPO) as an intermediate species. However, attempts were made to directly synthesize PPO to produce glufosinate therefrom, such as provided in US 9,850,263 B2. However, the suggested process includes cyanohydrine intermediate species. The presence of such species, in particular in an industrial context, bears the potential risk of exposure of hydrocyanic acid, which can be deadly even at minimal doses.

[0006] Summary of the Invention

[0007] Thus, it is an object of the present invention to provide a process for the preparation of L- glufosinate via a PPO intermediate, wherein the PPO intermediate is synthesized from a species different from D-glufosinate or a cyanohydrine or a similar, potentially hydrocyanic- acid producing starting material or intermediate. It is further an object of the present invention to provide a composition comprising L-glufosinate, which is essentially free of any cyanohydrine or a similar, potentially hydrocyanic-acid producing starting material or intermediate. Finally, it is an objection of the present invention to find a method of selectively controlling weeds in an area comprising a crop of planted seeds or crops that are resistant to glufosinate using a composition comprising L-glufosinate, which is essentially free of any cyanohydrine or a similar, potentially hydrocyanic acid producing starting material or intermediate.

[0008] It has now been surprisingly found that above-mentioned objects can be achieved by a process for the preparation of L-glufosinate, the process comprising the following steps: a) reacting a compound according to formula (I) wherein R1is hydrogen, (C1-C12)-alkyl, (C1-C12)-haloalkyl, (C6-C10)-aryl, (C6-C10)-haloaryl, (C7-C10) -a ra I kyl , (C7-C10)-haloaralkyl, (C4-C10)-cycloalkyl, or (C4-C10)-halocycloalkyl, with a compound according to formula (II) (ID wherein R2and R3are independently from each other (C1-C8)-acyloxy, (Cj-Cg -alkoxy or hydroxy, or R2and R3form together an epoxide group or an ethylene carbonate group, and optional subsequent acidic treatment to form a diol according to formula (III) b) Oxidizing the diol according to formula (I II) to form 2-oxo-4- (hydroxy(methyl) phosphinoyl) butyric acid (PPO); and c) aminating the PPO to L- glufosinate.

[0009] Furthermore, it has been surprisingly found that above-mentioned object can be achieved by a composition comprising 2-oxo-4-(hydroxy(methyl) phosphinoyl) butyric acid (PPO) according to formula (IV)

[0010] (IV), and aditional ly a diol according to formula (I II) and L-glufosinate.

[0011] Finally, it has been surprisingly found that above-mentioned object can be achieved by a method of selectively controlling weeds in an area comprising a crop of planted seeds or crops that are resistant to glufosinate using a composition comprising 2-oxo-4- (hydroxy(methyl)phosphinoyl)butyric acid (PPO) according to formula (IV)

[0012] (IV), and aditionally a diol according to formula (III)

[0013] (III), and L-glufosinate.

[0014] The present invention has the particular advantage that L-glufosinate can be specifically produced without the need to provide D-glufosinate or a racemic mixture of glufosinates and without the potential formation of hydrocyanic acid. Thus, the process for the preparation of L-glufosinate according to the invention, the composition comprising L- glufosinate according to the invention and the method of selectively controlling weed according to the invention have the advantage of a reduced health risk.

[0015] Definitions

[0016] The term “ (C^Cj-alky / ' as used herein denotes the abbreviated notation for an alkyl radical having 1 to 4 carbon atoms, therefore encompassing the radicals methyl, ethyl, 1-propyl, 2- propyl, 1-butyl, 2-butyl, 2-methylpropyl or tert-butyl. Correspondingly, general alkyl radicals with a greater stated range of C atoms, as for example “(C1-C6)-alkyl", also encompass straight-chain or branched alkyl radicals having a greater number of C atoms, i.e., according to example, the alkyl radicals also having 5 and 6 C atoms.

[0017] The term “ (C--C4)-a / kox as used herein denotes the abbreviated notation for an alkoxy radical having 1 to 4 carbon atoms, therefore encompassing the radicals methoxy, ethoxy, 1- propoxy, 2-propoxy, 1-butoxy, 2-butoxy, 2-methylpropoxy or tert-butoxy. Correspondingly, general alkyl radicals with a greater stated range of C atoms, as for example “(Cj-Cg)- alkoxy”, also encompass straight-chain or branched alkoxy radicals having a greater number of C atoms, i.e., according to example, the alkoxy radicals also having 5 and 6 C atoms.

[0018] The term “ (Cg-C^-acyiox as used herein denotes the abbreviated notation for an acyloxy radical having 1 to 4 carbon atoms, therefore encompassing the radicals formyloxy, acetyloxy, 1-propionyloxy, or 2-propionyloxy. Correspondingly, general acyloxy radicals with a greater stated range of C atoms, as for example “ (Cg-Cg)- acyiox , also encompass straight-chain or branched alkyl radicals having a greater number of C atoms, i.e., according to example, the acyloxyradicals also having 5 and 6 C atoms.

[0019] The term “halogen” as used herein denotes a member of the group consisting of fluorine, chlorine, bromine and iodine.

[0020] The terms “ haloalkyl' , “ ha loaryl' , “ haloaralkyl' and “ halocycloalkyl' as used herein denote alkyl, aryl, aralkyl and cycloalkyl, respectively, that are partly or wholly substituted by identical or different halogen atoms, preferably from the group of fluorine, chlorine and bromine, more particularly from the group of fluorine and chlorine. Thus, for example, haloalkyl encompasses monohaloalkyl (=monohalogenoalkyl), dihaloal kyl

[0021] (=d i h a I ogen oa I ky I) , trihaloal kyl (=tri h a I oge n oa I ky I) , or else perhaloa I kyl , such as, for example, CF3, CHF2, CH2F, CF3CF2, CH2FCHCI, CCI3, CHCI2, CH2CH2CI. Corresponding comments apply to the other radicals substituted by halogen.

[0022] The preparation of the compounds according to formula (I) is known to the skilled person and can take place in accordance with processes known from the literature (e.g. U.S. Pat. No. 3,914,345; U.S. Pat. No. 4,474,711; U.S. Pat. No. 4,485,052; U.S. Pat. No. 4,839,105; U.S. Pat. No. 5,128,495).

[0023] The term “portion” as used herein denotes only part of the total amount used in the process of the invention is used in the procedure defined at that particular point.

[0024] As used in this specification and in the appended claims, the singular forms of "a" and "an" also include the respective plurals unless the context clearly dictates otherwise. I n the context of the present invention, the terms "about" and "approximately" denote an interval of accuracy that a person skilled in the art will understand to still ensure the technical effect of the feature in question. The term typically indicates a deviation from the indicated numerical value of ± 20 %, preferably ± 15 %, more preferably ± 10 %, and even more preferably ± 5 %. It is to be understood that the term "comprising" is not limiting. For the purposes of the present invention the term "consisting of" is considered to be a preferred embodiment of the term "comprising of". If hereinafter a group is defined to comprise at least a certain number of embodiments, this is meant to also encompass a group which preferably consists of these embodiments only. Furthermore, the terms "first", "second", "third" or "(a)", "(b)", "(c)", "(d)" etc. and the like in the description and in the claims, are used for distinguishing between similar elements and not necessarily for describing a sequential or chronological order. It is to be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the invention described herein are capable of operation in other sequences than described or illustrated herein. In case the terms "first", "second", "third" or "(a)", "(b)", "(c)", "(d)", "i", "ii" etc. relate to steps of a method or use or assay there is no time or time interval coherence between the steps, i.e. the steps may be carried out simultaneously or there may be time intervals of seconds, minutes, hours, days, weeks, months or even years between such steps, unless otherwise indicated in the application as set forth herein above or below. It is to be understood that this invention is not limited to the particular methodology, protocols, reagents etc. described herein as these may vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of the present invention that will be limited only by the appended claims. Unless defined otherwise, all technical and scientific terms used herein have the same meanings as commonly understood by one of ordinary skill in the art.

[0025] As used herein the term "does not comprise” or "free of means in the context that the composition of the present invention is free of a specific compound or group of compounds, which may be combined under a collective term, that the composition does not comprise said compound or group of compounds in an amount of more than 0.8 wt.-%, based on the total weight of the composition. Furthermore, it is preferred that the composition according to the present invention does not comprise said compounds or group of compounds in an amount of more than 0.5 wt.-%, preferably the composition does not comprise said compounds or group of compounds at all.

[0026] The term " piatinum-group metais" as used therein denotes the chemically closely related metals platinum, palladium, iridium, rhodium, ruthenium, and osmium, which in nature generally occur together. The use of platinum or palladium, especially platinum, is preferred.

[0027] Ther term "aqueous alkaline medium" as used herein denotes a reaction mixture that reacts alkaline, i.e. which has a pH value of larger than 7.

[0028] Detailed Description of the Invention

[0029] As mentioned above, the present invention is concerned with a process for the preparation of L-glufosinate, a composition comprising L-glufosinate, and a method for controlling weed. These three embodiments will be described in the following in detail. Process according to the invention

[0030] Hence, the most general embodiment of the process for the preparation of L-glufosinate according to the present invention relates to process for the preparation of L-glufosinate, the process comprising the following steps: a) reacting a compound according to formula (I)

[0031] O ii

[0032] — P-H

[0033] OR1wherein R1is hydrogen, (C1-C12)-alkyl, (C1-C12)-haloalkyl, (C6-C10)-aryl, (C6-C10)- haloaryl, (C7-C10) -a ra I ky I , (C7-C10)-haloaralkyl, (C4-C10)-cycloalkyl, or (C4-C10)- halocycloa I ky I , with a compound according to formula (II) wherein R2and R3are independently from each other (C1-C8)-acyloxy, (C1-C8)-alkoxy or hydroxy, or R2and R3form together an epoxide group or an ethylene carbonate group, and optional subsequent acidic treatment to form a diol according to formula (III) b) Oxidizing the diol according to formula (III) to form 2-oxo-4- (hydroxy(methyl)phosphinoyl)butyric acid (PPO); and c) aminating the PPO to L-glufosinate.

[0034] Step a): Addition step

[0035] In step a) of the process according to the present invention, a phosphonated diol is produced, whereby intermediately a phosphonated diol derivative may be formed. Thereby, the reaction as used in step a) of the process according to the present invention comprises the addition of a phosphorous comprising species according to formula (I) to the C=C double bond of the diol or diol derivative according to formula(ll). Hence, step a) of the process according to the present invention comprises, preferably consists of, reacting a compound according to formula (I)

[0036] O ii — P-H

[0037] OR1wherein R1is hydrogen, (C1-C12)-alkyl, (C1-C12)-haloalkyl, (C6-C10)-aryl, (C6-C10)-haloaryl, (C7-C10) -a ra I kyl , (C7-C10)-haloaralkyl, (C4-C10)-cycloalkyl, or (C4-C10)-halocycloalkyl, with a compound according to formula (II) (ID wherein R2and R3are independently from each other (C1-C8)-acyl, (C1-C8) -al kyl or hydrogen, or R2and R3form together an epoxide group or an ethylene carbonate group, and optional subsequent acidic treatment to form a diol according to formula (III)

[0038] Preferably, R1in formula (I) of step a) of the process according to the present invention is (Cj-Cg) -al kyl, (C1-C6)-haloalkyl, (C6-C8)-aryl, (C6-C8)-haloaryl, (C7-C10) -ara I kyl , (C7-C10)- haloaralkyl, (C5-C8)-cycloalkyl or (C5-C8)-halocycloalkyl.

[0039] In another preferred embodiment of the process according to the present invention, R1in formula (I) of step a) is a Cj-Cg alkyl, more preferably is selected from methyl, ethyl, and n- butyl, and most preferably is n-butyl.

[0040] In an especially preferred embodiment of the step a) of the process according to the present invention, in the compound according to formula (I) R1is n-butyl.

[0041] In another preferred embodiment of the process according to the present invention, R2and R3in formula (II) of the step a) of the process according to the present invention are independently from each other acetyloxy, ethoxy, or n-butoxy, or R2and R3form together an ethylene carbonate group. Especially preferred embodiments of the compound according to formula (II) are selected from the compound according to formula (II), wherein R2is hydroxy and R3is hydroxy, the compound according to formula (II), wherein R2is hydroxy and R4is acetyloxy, the compound according to formula (II), wherein R3is acetyloxy and R4is hydroxy, the compound according to formula (II), wherein both R3and R4are acetyloxy, and the compound according to formula (II), wherein R3and R4form an ethylene carbonate group. Even more especially preferred embodiments of the compound according to formula (II) are selected from the compound according to formula (II) wherein both R3and R4are acetyloxy, and the compound according to formula (II) wherein R3and R4form an ethylene carbonate group. Most preferably, the compound according to formula (II) is the compound according to formula (II), wherein R3and R4form an ethylene carbonate group.

[0042] The respective alkyl chains as used in the radicals R1, R2, and R3of formulae (I) and (II) of step a) of the process of the present invention may in each case be straight-chain or branched-chain (branched) in the carbon scaffold. The step a) of the process according to the present invention is preferably carried out at a temperature in the range of from 60 to 95 ° C, more preferably in the range from 65 to 90 ° C.

[0043] In an alternatively especially preferred embodiment of the step a) of the process according to the present invention, in the compound according to formula (I) R1is hydrogen. Suitable and preferred compounds according to formula (I) include the following: methanephosphonous acid mono(C1-C6)-alkyl esters, monododecyl methanephosphonate, and monophenyl methanephosphonate.

[0044] Moreover, the process according to the present invention is preferably carried out under conditions in which free radicals are formed. Hence, the reaction of the compounds according to formula (I) and (II) to give the compound according to formula (III) in step a) of a process according to the present invention is preferably carried out with the aid of a radical-forming radiation source (such as UV, gamma or X-rays) or in the presence of one or more radical-forming substances.

[0045] Even more preferably, the reacting of the step a) of the process according to the present invention is carried out with aid of a radical-forming radiation source or in the presence of one or more radical-forming substance. An example for the one or more radical-forming substance is 2,2’-azobis(isobutyronitrile) (AIBN).

[0046] However, preferably, the one or more radical-forming substance comprises a compound according to formula (VI) wherein R4is methyl, ethyl, 2,2-dimethyl propyl or phenyl,

[0047] R5independently at each occurrence is (C1-C10)-alkyl, and

[0048] R6is hydrogen or (C1-C10)-alkyL

[0049] Most preferably, in the one or more radical-forming substance according to formula (VI) R5independently from each other is (Cj-C4) -a I kyl and R6is hydrogen or (C!-C4) -alkyl.

[0050] Hence, preferably the one or more radical-forming substance according to formula (VI) is selected from the group consisting of tert-butyl peroxypivalate, tert-amyl peroxypivalate, tert-butyl peroxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, tert- butylperoxy-2-ethylhexanoate, 1,1,3,3-tetramethylbutyl peroxy-2-ethyl hexanoate, tert-amyl peroxyneodecanoate, cumyl peroxyneodecanoate, cumyl peroxyneoheptanoate, cumyl peroxypivalate, and mixtures thereof, more preferably selected from the group consisting of tert-butylperoxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, tert- butylperoxy-2-ethylhexanoate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, cumyl peroxyneodecanoate, and mixtures thereof, and most preferably selected from the group consisting of 1,1,3,3-tetramethylbutyl peroxyneodecanoate, tert-butyl peroxyneodecanoate, tert-butylperoxy-2-ethylhexanoate, and mixtures thereof.

[0051] Preferably, in step a) of the process according to the present invention, the molar ratio of the total amount of the compound according to formula (II) used to the total amount of the compound according to formula (II) used is in a range from 2:1 to 8:1.

[0052] Also preferably, in step a) of the process according to the present invention the one or more radical-forming substance is premixed with a portion or the entirety of compound (I), and this mixture is added into the reaction vessel simultaneously with the compound according to formula (II).

[0053] The one or more radical-forming substances stated as preferred, in particular, permit a very good reaction regime under mild reaction conditions, more particularly within the temperature range stated as preferred, thereby allowing the desired phosphorus-comprising diols according to formula (III) to be obtained in high yields and high purity.

[0054] Preferably, a total of 0.1 to 10 mol-%, more preferably 0.25 to 7 mol-%, even more preferably 0.5 to 7 mol-%, especially preferably 0.5 to 5 mol-%, of one or more radical-forming substances according to formula (VI), based on the total amount of diol or diol derivative according to formula (II) is used in the process according to the present invention.

[0055] The one or more radical-forming substance according to formula (VI), or a mixture of one or more radical-forming substances according to formula (VI), may be mixed together with the diol or diol derivative according to formula (II), and the mixture added, preferably under dosage control, to the initially introduced compound according to formula (I).

[0056] Alternatively, the one or more radical-forming substance or a mixture of one or more radical-forming substances according to formula (VI) may also be mixed with the phosphorus-comprising reactant according to formulae (I) or added, preferably under dosage control, in pure form simultaneously separately alongside the diol or diol derivative according to formula (II).

[0057] The step a) of the process of the invention can be carried out such that the one or more radical-forming substances according to formula (VI), or a portion of the one or more radical-forming substances according to formula (VI), is premixed with a portion or the entirety of the compound according to formula (II) (“mixture Vl + ll”) and this mixture, i.e. “mixture Vl + ll”, is added into the reaction vessel.

[0058] The step a) of the process of the invention is preferably carried out such that compound according to formula (II) is premixed with a portion of the compound according to formula (I) (“mixture ll + l”), spatially separately therefrom (i.e. in a separate container), a portion of the compound according to formula (I) is premixed with the one or more radical-forming substance (VI) (“mixture l+VI”), and these two mixtures, i.e. “mixture ll + l” and “mixture l+VI”, are added simultaneously into the reaction vessel.

[0059] The step a) of the process according to the present invention is preferably carried out such that the one or more radical-forming substances according to formula (VI) or a portion of the one or more radical-forming substances according to formula (VI) is or are premixed with a portion or the entirety of the compound according to formula (I) (“mixture Vl + I ”) , and this mixture, i.e. “mixture Vl+I ”, is added simultaneously with and separately from the compound according to formula (II) into the reaction vessel.

[0060] The compound according to formula (II) is preferably added into the reaction vessel from a separate container that constitutes a separate construction.

[0061] If the step a) of the process according to the present invention is carried out in batch mode, and depending on the batch size, the simultaneous adding in each of the above-mentioned procedures lasts preferably for longer than 30 min, more preferably 30 min to 20 h, and most preferably 1 to 12 h.

[0062] The above-defined mixtures “mixture Vl + ll”, “mixture Vl + I”, “mixture ll + l”, and “mixture l+VI” are likewise provided by the present invention.

[0063] The present invention consequently also relates to a mixture selected from the group consisting of a mixture comprising one or more compounds according to formula (VI) and one or more compounds of the compound according to formula (II), a mixture comprising one or more compounds according to formula (VI) and one or more compounds according to formula (I), a mixture comprising one or more compounds according to formula (II) and one or more compounds according to formula (I), wherein such a mixture preferably contains no compound of the above-defined formula (VI) and / or no compound of the abovedefined formula (III), wherein the compounds according to formulae (I), (II) and (VI) each have the structure defined above, preferably in each case a structure defined above as preferred or particularly preferred.

[0064] The present invention preferably relates to a mixture selected from the group consisting of a mixture comprising one or more compounds according to formula (VI) and one or more compounds according to formula (II), a mixture comprising one or more compounds according to formula (VI) and one or more compounds according to formula (I), wherein the compounds according to formulae (I), (II) and (VI) each have the structure defined above, preferably in each case a structure defined above as preferred or particularly preferred.

[0065] Preferred mixtures of the invention comprise or consist of one or more radical-forming substances according to formula (VI) Hence, preferably the one or more radical-forming substance according to formula (VI) is selected from the group consisting of tert-butyl peroxypivalate, tert-amyl peroxypivalate, tert-butyl peroxyneodecanoate, 1, 1,3,3- tetramethylbutyl peroxyneodecanoate, tert-butylperoxy-2-ethylhexanoate, 1, 1,3,3- tetramethylbutyl peroxy-2-ethyl hexanoate, tert-amyl peroxyneodecanoate, cumyl peroxyneodecanoate, cumyl peroxyneoheptanoate, and cumyl peroxypivalate, and a compound according to formula (II), more preferably selected from the group consisting of tert-butylperoxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, tert- butylperoxy-2-ethylhexanoate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, and cumyl peroxyneodecanoate, and a compound according to formula (II), and most preferably selected from the group consisting of 1,1,3,3-tetramethylbutyl peroxyneodecanoate, tertbutyl peroxyneodecanoate, and tert-butylperoxy-2-ethylhexanoate, and a compound according to formula (II).

[0066] Preferred mixtures of the invention comprise or consist of one or more radical-forming substances according to formula (VI) Hence, preferably the one or more radical-forming substance according to formula (VI) is selected from the group consisting of tert-butyl peroxypivalate, tert-amyl peroxypivalate, tert-butyl peroxyneodecanoate, 1, 1,3,3- tetramethylbutyl peroxyneodecanoate, tert-butylperoxy-2-ethylhexanoate, 1, 1,3,3- tetramethylbutyl peroxy-2-ethyl hexanoate, tert-amyl peroxyneodecanoate, cumyl peroxyneodecanoate, cumyl peroxyneoheptanoate, and cumyl peroxypivalate, and a compound according to formula (I), more preferably selected from the group consisting of tert-butylperoxyneodecanoate, 1,1,3,3-tetramethylbutyl peroxyneodecanoate, tert- butylperoxy-2-ethylhexanoate, 1,1,3,3-tetramethylbutyl peroxy-2-ethylhexanoate, and cumyl peroxyneodecanoate, and a compound according to formula (I), and most preferably selected from the group consisting of 1,1,3,3-tetramethylbutyl peroxyneodecanoate, tertbutyl peroxyneodecanoate, and tert-butylperoxy-2-ethylhexanoate, and a compound according to formula (I).

[0067] The step a) of the process according to the present invention enables the preparation of the phosphorus-comprising diols according to formula (III) under mild reaction conditions, thereby giving the phosphorus-comprising diols according to formula (III) in very good yields.

[0068] Accordingly, when the step a) of the process of the present invention is implemented, disproportionation of reactants according to formulae (I), for example, is significantly lessened or largely prevented. Moreover, when the process of the invention is implemented, polymerization of the compounds according to formula (II) is significantly lessened or largely prevented.

[0069] It has further been found that by premixing (parts) of the reactants according to formulae (I) and (II), the polymerization tendency of compounds according to formula (II) can be still further reduced.

[0070] In the context of the step a) of the process of the invention it is advantageous to use the diols or diol derivatives according to formula (II) in a very high purity. The diols or diol derivatives according to formula (II) are preferably used in a purity of greater than or equal to 90 wt.-%, more preferably of greater than or equal to 92 wt.-%.

[0071] In order to avoid unwanted secondary reactions in step a) of the process according to the present invention, and, hence, to achieve high yields, moreover, it is advantageous to use the phosphorus-comprising reactant according to formula (I) in a molar excess, relative to the compound according to formula (II).

[0072] In the step a) of the process according to the present invention, the molar ratio of the total amount of the phosphorus-comprising reactant according to formulae (I) used to the total amount of the compound according to formula (II) used is preferably in the range from 3:2 to 8:1, more preferably in the range from 2:1 to 6:1, more preferably still in the range from 5:2 to 5:1, very preferably in the range from 2.8:1 to 4.0:1.

[0073] The step a) of the process of the invention can be carried out either in batch mode or in continuous mode (i.e. continuous operating regime).

[0074] The step a) of the process of the invention is carried out preferably with inertizing, more preferably in an inert gas atmosphere. Preferred inert gases in this case are nitrogen and argon.

[0075] It is further possible to carry out the step a) of the process of the invention under superatmospheric pressure or under reduced pressure.

[0076] The step a) of the process of the invention can be carried out in a diluent.

[0077] As diluents it is possible in principle to use a variety of organic solvents, preferably toluene, xylene, chlorobenzene, dichlorobenzene, dimethylformamide (DMF), dimethylacetamide, N- methyl-2-pyrrolidone (NMP), or mixtures of these organic solvents. The step a) of the process of the present invention is preferably carried out without such solvents.

[0078] It may, however, be advantageous to carry out the step a) of the process of the invention in reaction product according to formula (Illi), already formed beforehand, as diluent.

[0079] It may be advantageous to carry out the step a) of the process of the invention in the reactant according to formula (I) as diluent, in which case preferably a portion of the reactant according to formula (I) is introduced as an initial charge to the reaction vessel or reactor.

[0080] Particularly in the case of continuous mode, it is advantageous to carry out the step a) of the process of the invention in reaction product according to formula (III), already formed beforehand, or in a mixture of reaction product according to formula (III) and reactant according to formulae (I), as diluent.

[0081] The yields according to the step a) of the process of the invention amount regularly to 90- 98%, based on the component according to formula (II), and regularly to 88-96%, based on the component according to formula (I).

[0082] The purity of the products after purification, for example after disti I lative removal of the excess of component according to formulae (I), amounts regularly to 90% to 96%. The recovered excess of the starting compound according to formula (I) can be used subsequently without further purification in the same reaction again.

[0083] If the intermediate product of step a) of the process according to the present invention, are not present as free diols already, but rather as diol derivatives, i.e. if in formula (II) R2and R3 are independently from each other (C1-C8)-acyloxy or (C1-C8)-alkoxy, or R2and R3form together an epoxide group or an ethylene carbonate group, the intermediate product of step a) of the process according to the present invention is subsequently to the step a) treated with an acid, wherein the compound according to formula (III) is formed.

[0084] Preferably, the acid treatment of step a) of the process according to the present invention is carried out in an aqueous medium. Also preferably, the acid treatment step a) of the process according to the present invention is carried out using hydrochloric acid. The acid treatment step a) of the process according to the present invention is preferably carried out at a temperature of 80 to 100 ° C.

[0085] Step b): Oxidation step

[0086] In step b) of the process according to the present invention, the diol according to formula (III) is oxidized to form 2-oxo-4-(hydroxy(methyl)phosphinoyl)butyric acid (PPO).

[0087] Hence, step b) of the process of the present invention is concerned with preparing 2-oxo-4- (hydroxy(methyl)phosphinoyl)butyric acid (PPO) of formula (VII) comprising oxidizing in an oxidating step (0) a diol of formula (III)

[0088] It should be understood that as a side reaction, the oxidation may also lead to a hydroxymethyl ketone according to formula (VIII)

[0089] (VIII).

[0090] The step b) according to the process of the present invention can be carried out in the presence of an enzyme (step bl)) or a chemical catalyst (step b2)).

[0091] Step bl): Oxidation in the presence of an enzyme

[0092] In the following the step bl) of the process according to the present invention is described, which is carried out in the presence of an enzyme. Preferably, the enzyme, which is present in step bl) of the process according to the present invention, is an Oxidoreductase ECI enzyme. More preferably, the Oxidoreductase ECI enzyme is selected from the group consisting of EC1.1, EC1.2 or EC1.10, more preferably EC1.1.1, EC1.1.3, EC1.2.1, EC1.2.3. Most preferably, the Oxidoreductase ECI enzyme is an enzyme according to SEQ ID NO:1-1, preferably of SEQ ID NO:10. Preferably, not only one enzyme can be used, but combinations of Oxidoreductases ECI, preferably a combination of the classes EC1.1 and EC1.2.

[0093] The step bl) of the process according to the present invention is preferably carried out at a reaction temperature in the range of from 25 to 45 ° C, more preferably 30 to 42 ° C, and most preferably 35 to 40 ° C. Also preferably, step bl) of the process according to the present invention is carried out in an aqueous solution, preferably a buffered aqueous solution. Most preferably, the pH value of the buffered aqueous solution is in the range of from 8.8 to 7.2, most preferably the pH value of the buffered aqueous solution is 7. Preferably, the buffer aqueous solution is a solution of ammonia in water. Moreover, preferably, step bl) of the process according to the present invention is carried out for a period in the range of from 5 to 48 H.

[0094] Preferably, the step bl) of the process according to the present invention is carried out in an ex vivo environment.

[0095] The step bl) of the process of the present invention is preferably carried out in the presence of a Catalase enzyme in addition to the Oxidase enzyme, preferably a Catalase enzyme according to CAS-Nr. 9001-05-2. It has been surprisingly found that the presence of the Catalase enzyme significantly improves the yields of the compound according to formula (I). Without wishing to be bound by theory it is believed that the improvement in yield is caused by the removal of intermediately formed hydrogen peroxide from the reaction mixture in the oxidating step.

[0096] Step b2): Oxidation in the presence of a chemical catalyst

[0097] In the following the step b2) of the process according to the present invention is described, which is carried out in the presence of a chemical catalyst as step.

[0098] Hence, in step b2) of the process according to the present invention, the chemical catalyst is preferably a platinum-group metal catalyst.

[0099] Moreover, preferably, step b2) of the process according to the present invention is carried out in the presence of a gas comprising molecular oxygen.

[0100] Finally, preferably, step b2) of the process according to the present invention is carried out in the presence and an activator. Hence, more preferably, step b2) of the process according to the present invention is carried out in the presence of a chemical catalyst, preferably a platinum-group metal catalyst, in the presence of a gas comprising molecular oxygen and an activator.

[0101] Preferably, the step b2) of the process according to the present invention is carried out in basic aqueous solution, preferably in an aqueous solution of an amine. Preferably the step b2) of the process according to the present invention is carried out in aqueous solution of a compound selected from the list consisting of ammonia, glutamate, L-glutamate, lysine, alanine, isopropylamine, sec-butylamine, and phenylethylamine.

[0102] The platinum-group metal used as the chemical catalyst in the step b2) of the process according to the present invention can be added to the reactants in a variety of forms, for example in elementary, i.e. metallic, form, for instance as so-called "black", in combination with other platinum-group metals or in the form of a compound, for example as an oxide or also in the form of some other compound. Preferably, the platinum-group metal used as the chemical catalyst step b2) of the process according to the present invention is present in metallic form. Also preferably, the platinum-group metal catalyst used as the chemical catalyst in the step b2) of the process according to the present invention is selected from platinum and palladium.

[0103] The platinum-group metals used as the chemical catalyst in the step b2) of the process according to the present invention can be applied to supports yielding a supported platinum-group metal catalyst. Preferably, the support of the supported platinum-group metal catalyst as used in the step b2) of the process according to the present invention is selected from the group consisting of active charcoal, graphite, kieselguhr, silica gel, spinels, aluminum oxide, asbestos, calcium carbonate, magnesium carbonate, barium sulphate, or organic support material. Active charcoals have proved particularly suitable, for example, inexpensive pulverulent active charcoals, produced from wood, which are extensively used for decolorizing purposes. Hence, preferably, the platinum-group metal catalyst used in the step b2) of the process according to the present invention is a supported platinum-group metal catalyst, more preferably a charcoal supported platinum- group metal catalyst.

[0104] The amount of the platinum-group metal comprised in the supported platinum-group metal catalyst as used in the step b2) of the process according to the present invention can be less than 10 wt.-% with respect to the total weight of the supported platinum-metal group catalyst, preferably is in the range of from 0.1 to 5 wt.-%.

[0105] Furthermore, the platinum-group metal catalyst as used in the step b2) of the process according to the present invention preferably comprises an activator. More preferably, the activator is selected from lead and / or a compound thereof and / or bismuth and / or a compound thereof.

[0106] The amount in which the platinum-group metal catalyst is used in the step b2)of the process according to the present invention depends on the desired rate of oxidation, the form of the catalyst, the nature and amount of the activator, and so on, and can in a specific case easily be determined by preliminary experiments.

[0107] Preferably, the amount of platinum-group metal used per mole compounds according to formula (III) in the step b2) of the process according to the present invention is less than 1,000 mg. In most cases sufficiently high reaction rates are achieved with an amount of platinum-group metal of 20 to 400 mg per mole of compounds according to formula (III).

[0108] It has been found that tar formation is avoided when using the platinum-group metal catalyst in the step b2) of the process according to the present invention. Hence, the platinum-group metal catalysts used in the step b2) of the process according to the present invention can be used repeatedly. As a result of this reuse, the consumption of platinum- group metal catalyst per mole of compounds according to formula (III) can be reduced to 5 mg or less, before reprocessing of the platinum-group metal catalyst becomes necessary.

[0109] Preferably, in the step b2) of the process according to the present invention, the activator is present in an amount of less than 0.1 mole or more with respect to the amount of compounds according to formula (III), more preferably of 5 x 10’5to 1 x 10’1mole, even more preferably 1 x 10’4to 1 x 10’2mole.

[0110] The activator as used in the step b2) of the process according to the present invention preferably comprise the metals lead and / or bismuth as such, that is to say in the elementary form, and / or in the form of their compounds, for example as oxides, or as salts of hydracids, such as chlorides, bromides, iodides, sulfides, selenides and tellurides; or as salts of inorganic oxy-acids, such as nitrates, nitrites, phosphites, phosphates, sulfates, carbonates, perchlorates, antimonates, arsenates, selenites, selenates, and borates; or as salts of oxy-acids derived from transition metals, for example vanadates, niobates, tantalates, chromates, molybdates, tungstates, and permanganates; or as salts of organic aliphatic or aromatic acids, for example formates, acetates, propionates, benzoates, salicylates, lactates, mandelates, glyoxylates, arylglyoxylates and citrates; or as phenolates and the like. The activators may, in each particular case, be soluble, partially soluble or insoluble in the reaction mixture.

[0111] Hence, the activator used in the step b2)of the process according to the present invention preferably comprises one or more compounds selected from the group consisting of lead in elemental form, bismuth in elemental form, lead in oxide form, bismuth in oxide form, lead in hydracid salt form, bismuth in hydracid salt form, lead in form of a salt of an inorganic oxyacid, bismuth in form of a salt of an inorganic oxyacid, lead in form of a salt of a transition-metal-comprising oxyacid, bismuth in form of a salt of a transition-metal- comprising oxyacid, lead in form of a salt of an organic aliphatic or aromatic acid, and bismuth in form of a salt of an organic aliphatic or aromatic acid, more preferably is selected from lead in elemental form and bismuth in elemental form, and most preferably is bismuth in elemental form.

[0112] In a preferred embodiment of the process according to the present invention, in the step b2) , combinations of these activators with one another and / or with other elements or compounds, not specified as an activator, can also be used. The activators as used in the step b2) of the process according to the present invention may be present in various valency levels or in a mixture of valency levels. Furthermore, changes in valency may also occur during the reaction. If the activators have not already been added as oxides and / or hydroxides, it is possible that they become entirely or partially converted to these in the alkaline medium. After the reaction, the platinum-group metal catalyst can be filtered off together with the sparingly soluble activator and be reused in further oxidation reactions. Losses of platinum-group metal catalyst and / or activator, if these occur, must be made up.

[0113] The activator used in the step b2) of the process according to the present invention can be added to the reactants as a solid, preferably in a finely divided form, or in the form of a solution. It is also possible to add the activator when preparing the platinum-group metal catalyst, or to impregnate the platinum-group metal catalyst with the activator. The activator can also serve as a support for the platinum metal. Preferably, the activator is incorporated into the platinum-group metal catalyst.

[0114] If the step b2) of the process according to the present invention is carried out in the presence of a chemical catalyst, the step b2) is preferably carried out in the presence of an aqueous alkaline medium.

[0115] The alkali of the aqueous alkaline medium of the step b2) of the process according to the present invention can be added to a solution or suspension of the compound according to formula (III), or the compound according to formula (III) can be dissolved or suspended in the aqueous alkaline solution. Preferably, the amount of alkali is chosen to provide 0.3 to 5, preferably 0.5 to 3, equivalents of alkali per mole of compound according to formula (III) to be oxidized. The use of from 0.9 to 2 equivalents of alkali per mole of compound according to formula (III) to be oxidized is particularly preferred.

[0116] Preferably, the alkali is selected from the list consisting of sodium hydroxide, potassium hydroxide, or carbonate, more preferably the alkali is selected from the list consisting of sodium hydroxide or potassium hydroxide, and most preferably the alkali is sodium hydroxide.

[0117] In the step b2) of the process according to the present invention, the concentration of the organic compounds in the aqueous alkaline reaction solution is in general selected so that both the diol according to formula (III) and the PPO according to formula (I) formed are present in solution under the reaction conditions. Where appropriate, the diol according to formula (III) should be added in portions to the oxidation mixture, preferably together with part of the alkali. Most preferably, the final concentration of organic compounds in the reaction mixture is in the range of from 5 to 30 wt.% with respect to the total weight of the oxidation mixture.

[0118] Under the conditions according to the invention, an oxidation effect is observable at all temperatures at which a liquid phase is present. Accordingly, the possible reaction temperature of the step b2) of the process according to the present invention ranges from the solidification point to the boiling point of the reaction mixture. Preferably, the step b2) is carried out at a temperature of from 10 to 100 ° C, preferably 25 to 85 ° C, and most preferably 45 to 65 ° C.

[0119] The aerating step in the step b2) of the process according to the present invention can be carried out by bubbling gas comprising molecular oxygen through the reaction mixture. Alternatively, the gas comprising molecular oxygen can be applied under a pressure of 0.5 to 10 atm.

[0120] Preferably, the gas comprising molecular oxygen as used in the step b2) of the process according to the present invention can be pure oxygen or air.

[0121] The step b2) of the process of the present invention is preferably carried out in the presence of a Catalase enzyme, preferably a Catalase enzyme according to CAS-Nr. 9001- 05-2. It has been surprisingly found that the presence of the Catalase enzyme significantly improves the yields of PPO. Without wishing to be bound by theory it is believed that the improvement in yield is caused by the removal of intermediately formed hydrogen peroxide from the reaction mixture in the oxidating step.

[0122] If a Catalase enzyme is present in the reaction mixture in the step b2) of the process of the present invention when being carried out in the presence of a chemical catalyst, preferable a platinum-group metal catalyst, the reaction temperature is preferably in the range of from 25 to 45 ° C, more preferably 30 to 42 ° C, and most preferably 39 to 41 ° C.

[0123] Step c): Amination step The step c) of the process according to the present invention is the specific amination of PPO to L-glufosinate using an amine group from one or more amine donors. Such amine donors can be selected from glutamate, L-glutamate, lysine, alanine, isopropylamine, secbutylamine, phenylethylamine and the like. The step c) can be enzymatically catalyzed or achieved by chemical conversion. If step c) is enzymatically catalyzed, it is preferably catalyzed by a transaminase (TA) enzyme or an L-amino acid dehydrogenase (LAAD) enzyme. Using the step c) of the process as described herein, compositions of substantially purified L-glufosinate can be obtained.

[0124] The step c) of the process of the present invention involves the conversion of PPO to L- glufosinate using a transaminase (TA) enzyme (step cl)), or an L-amino acid dehydrogenase (LAAD) enzyme (step c2)).

[0125] Step cl): Amination by a transaminase (TA)

[0126] In one embodiment, the step c) of the process according to the present invention is a reaction catalyzed by a TA (step cl)). A TA with the required stereospecificity that accepts PPO as a substrate catalyzes the amination of PPO to L-glufosinate with the following stoichiometry:

[0127] PPO + amine donor => L-glufosinate + keto acid.

[0128] The starting amounts of PPO are typically less than 1 g / L and the highest levels of PPO during the reaction are typically less than 25 g / L. The amine donor is initially present at between 1 and 50 fold molar excess over the starting amount of PPO.

[0129] Preferred TAs used in step cl) of the process according to the present invention include the gabT transaminase from Escherichia coli (UniProt P22256), which has been shown to catalyze the desired reaction with PPO as a substrate (Bartsch et al. (1990) Appl Environ Microbiol. 56(1):7-12). Another enzyme has been evolved to catalyze the desired reaction at a higher rate using isopropylamine as an amine donor (Bhatia et al. (2004) Peptide Revolution: Genomics, Proteomics & Therapeutics, Proceedings of the Eighteenth American Peptide Symposium, Ed. Michael Chorev and Tomi K. Sawyer, July 19-23, 2003, pp. 47-48). Additionally, TA enzymes from numerous microorganisms, such as Streptomyces hygroscopicus, Streptomyces viridochromogenes, Candida albicans, and others can be used in the step cl) of the process according to the present invention. In particular, see, for example, EP 0 249 188 Al, and U.S. Patent No. 5,162,212. Where desired, the enzymes can be evolved by mutagenesis to increase their activities. Mutant TA enzymes can be selected for desired activity by the assays outlined in Schulz et al., Appl Environ Microbiol. (1990) Jan. 56(1) :l-6, and / or by direct measurement of the products by HPLC, LC-MS, or similar products. Additional TA enzymes used in step cl) of the process according to the present invention can be identified by screening collections of TAs, such as those sold by Prozomix Limited (Northumberland, United Kingdom), SyncoZymes (Shanghai, China), Evocatal (Monheim am Rhein, Germany), Codexis (Redwood City, CA), or Abeam (Cambridge, United Kingdom) for the desired activity. Alternatively, sequence similarity can be used to identify novel TA enzymes. Finally, TA enzymes can also be identified from organisms capable of catalyzing the desired reaction.

[0130] The selection of an appropriate amine donor is important for an economical conversion of PPO to L-glufosinate. A variety of issues may be considered, including the cost of the donor, equilibrium thermodynamics, potential recovery of the donor, separation of the keto acid product from the desired L-glufosinate, and others. Consequently, TA enzymes that accept several different amine donors can be used, including low cost amine donors such as L- aspartate or racemic aspartate, L-glutamate or racemic glutamate, L-alanine or racemic alanine, L-phenylethylamine or racemic phenylalanine, L-glycine or racemic glycine, L- lysine or racemic lysine, L-valine or racemic valine, L-serine or racemic serine, L-glutamine or racemic glutamine, isopropylamine, sec-butylamine, ethanolamine, 2-aminobutyric acid, and diaminoproprionic acid. In some embodiments, the amine donor is not aspartate or aspartic acid (e.g., L-aspartic acid, D-aspartic acid, or racemic D,L-aspartic acid).

[0131] In embodiments where the amino donor is glutamate, the keto acid co-product that results from the transamination reaction is a -ketoglutarate (which is also referred to as a - ketoglutaric acid or a -KG). The a -ketoglutarate can be isolated and / or purified using methods known to those of skill in art, such as in EP Patent No. 0073711, CN Patent No. 10519873, CN Patent No. 105177065, CN Patent No. 104529755, and Zhan et al., Shipin Yu Shengwu Jishu Xuebao, 32(10): 1043-1048 (2013). The produced and isolated a - ketoglutarate can be used in a variety of applications, including in synthesizing pharmaceutical agents, food additives, and biomaterials. Optionally, the a -ketoglutarate can be chemically converted to either racemic glutamate or L-glutamate, optionally for reuse in the reaction.

[0132] A wild type TA that accepts a desired amine donor can be identified, or a TA that does not normally accept a desired amine donor can be evolved to accept the desired substrate. Optionally, the transaminase is not an aspartate transaminase. Optionally, the transaminase is not 4-amino-butyrate: 2-ketoglutarate transaminase. In some embodiments, the transaminase is not a combination enzyme system that includes a PPT-specific transaminase and glutamate:oxaloacetate transaminase.

[0133] Step c2): Amination by a L-amino acid dehydrogenase (LAAD) In another preferred embodiment of step c) of the process according to the present invention LAAD enzymes that accept PPO as a substrate are used for catalyzing the reaction (step c2)). Such LAAD enzymes use the following stoichiometry:

[0134] NH3+ reduced acceptor + PPO => L-glufosinate + H2O + acceptor.

[0135] LAAD catalyzed reactions can include redox cofactor recycling, which involves reducing the oxidized acceptor so that it can donate more electrons to PPO.

[0136] Steps cl) or c2) of the process according to the present invention are preferably carried out for a period of 24 hours, 18 hours, 12 hours, 8 hours, or 4 hours.

[0137] The enzymes used in steps cl) or c2) of the process according to the present invention can be added to the reaction by a number of methods. One preferably approach is to express the enzyme(s) in microorganism(s) such as E. coli, S. cerevisiae, P. pastoris, and others, and to add the whole cells to the reactions as whole cell biocatalysts. Another also preferably approach is to express the enzyme(s), lyse the microorganisms, and add the cell lysate. Yet another also preferably approach is to purify, or partially purify, the enzyme(s) from a lysate and add pure or partially pure enzyme(s) to the reaction. If multiple enzymes are required for a reaction, the enzymes can be expressed in one or several microorganisms, including expressing all enzymes within a single microorganism.

[0138] A further approach, which can be combined with the above approaches, is to immobilize enzyme(s) in the steps cl) or c2) of the process according to the present invention to a support (exemplary strategies are outlined in Datta et al. (2013) 3 Biotech. Feb; 3(1): 1-9). As outlined in Datta et al., and not intending to be limiting, enzymes, either singly or in combination, can, for example, be adsorbed to, or covalently or non-covalently attached to, or entrapped within, natural or synthetic polymers or inorganic supports, including aggregates of the enzyme(s) themselves. Once immobilized, the enzyme(s) and support can be dispersed into bulk solution or packed into beds, columns, or any number of similar approaches to interacting reaction solution with the enzymes. Since aeration is important for the DAAO reaction envisioned here, bubble columns or similar may be used for enzyme immobilization. As examples, reaction mixture can be flowed through a column of immobilized enzymes (flow reaction), added to a fixed bed or column of immobilized enzymes, allowed to react, and either removed from the bottom or top of the reaction vessel (plug flow), or added to dispersed immobilized enzymes and allowed to react then the immobilized enzymes removed by filtration, centrifugation, or similar (batch). Thus, any method for immobilization of the enzymes may be employed in the methods of the invention. Steps cl) or c2) of the process according to the present invention are preferably carried out in a buffer. Exemplary buffers commonly used in biotransformation reactions include Tris, phosphate, or any of Good’s buffers, such as 2-(N-morpholino)ethanesulfonic acid (MES); N-(2-Acetamido)iminodiacetic acid (ADA); piperazine-N,N' -bis(2-ethanesulfonic acid) (PIPES); N-(2-Acetamido)-2-aminoethanesulfonic acid (ACES); -Hydroxy-4- morpholinepropanesulfonic acid (MOPSO); cholamine chloride; 3-(N- morpholino)propanesulfonic acid (MOPS); N,N-Bis(2-hydroxyethyl)-2-aminoethanesulfonic acid (BES); 2-[[l,3-dihydroxy-2-(hydroxymethyl)propan-2-yl]amino]ethanesulfonic acid (TES); 4-(2-hydroxyethyl)-l-piperazineethanesulfonic acid (HEPES); 3-(Bis(2- hydroxyethyl)amino)-2-hydroxypropane-l-sulfonic acid (DIPSO); acetamidoglycine, 3-(N- Tris(hydroxymethyl)methylamino(-2-hydroxypropanesulfonic acid (TAPSO); Piperazine- N,N' -bis(2-hydroxypropanesulfonic acid) (POPSO); 4-(2-Hydroxyethyl)piperazine-l-(2- hydroxypropanesulfonic acid) (HEPPSO); 3-[4-(2-Hydroxyethyl)-l- piperazinyl]propanesulfonic acid (HEPPS); tricine; glycinamide; bicine; or 3- [[1,3-dihydroxy- 2-(hydroxymethyl)propan-2-yl]amino]propane-l-sulfonic acid (TAPS). Additional exemplary buffer recipes can be found in Whittail, J. and Sutton, P. W. (eds) (2012) Front Matter, in Practical Methods for Biocatalysis and Biotransformations 2, John Wiley & Sons, Ltd, Chichester, UK. In some embodiments, ammonium can act as a buffer. One or more organic solvents can also be added to the reaction.

[0139] Surprisingly, steps cl) or c2) of the process according to the present invention can be carried out with no or low levels (less than 1 mM) of buffer added (other than ammonium that may optionally be present due to addition of racemic glufosinate ammonium). In particular, immobilized LAAD and TA may be stable and active in the presence of less than 1 mM phosphate buffer and with no other buffer except any ammonium present due to the addition of racemic glufosinate ammonium.

[0140] Steps cl) or c2) of the process according to the present invention are preferably carried out within a defined pH range, which can be between pH 4 to pH 10 (e.g., between pH 6 and pH 9, such as approximately pH 7.5 to pH 8).

[0141] Steps cl) or c2) of the process according to the present invention are preferably carried out at a reaction temperature kept at a point between room temperature and the boiling point of the solvent, most typically between room temperature and 50 ° C.

[0142] Isolation of L-glufosinate

[0143] The process according to the present invention provides a composition of substantially pure L-glufosinate (rather than a racemic mixture of L-glufosinate and Diol according to formula (HD). In one embodiment, the L-glufosinate is not isolated from the biotransformation mixture and a composition comprising diol according to formula (III), PPO, and L-glufosinate is obtained. This composition will contain at least 80% L-glufosinate by weight of the sum of L-glufosinate, diol according to formula (III), and PPO, at least 90% L-glufosinate by weight of the sum of the components. This composition may be used directly as a herbicidal composition or as an ingredient in a formulated herbicidal product.

[0144] Alternatively, some or all of the components other than L-glufosinate can be removed from the mixture achieved by step c) of the process according to the present invention, the mixture optionally concentrated, and then the mixture can be used directly (and / or with the addition of various adjuvants) for the prevention or control of weeds. The biotransformation mixture, in some instances, can be used directly (and / or with the addition of various adjuvants) for the prevention or control of weeds.

[0145] Additional steps to further purify the L-glufosinate can be added. Such further purification and isolation methods include ion exchange, extraction, salt formation, crystallization and filtration; each may be used multiple times or in suitable combination. Enzymes can be removed by simple filtration if supported, or if free in solution by the use of ultrafiltration, the use of absorbents like celite, cellulose or carbon, or denaturation via various techniques known to those skilled in the art.

[0146] Ion exchange processes effect separation by selective adsorption of solutes onto resins chosen for this purpose. Because products and impurities must be dissolved in a single solution prior to adsorption, concentration of the purified product stream by evaporation or distillation prior to isolation is usually required. Examples of the use of ion exchange for purification are described by Schultz et al., and in EP0249188(A2).

[0147] Purification may be achieved by the formation of an insoluble salt of L-glufosinate by the addition of a suitable acid, including hydrochloric acid, sulfuric acid, phosphoric acid, nitric acid, acetic acid and the like. Similarly, the purification may be achieved by the addition of a suitable base to form an insoluble salt. Useful bases include hydroxides, carbonates, sulfates and phosphates of alkali metals or hydroxides, carbonates, sulfates and phosphates of alkali earth metals. Other bases which contain nitrogen may be used, including ammonia, hydroxylamine, isopropylamine, triethylamine, tributylamine, pyridine, 2- picoline, 3-picoline, 4-picoline, 2,4-lutidine, 2,6-lutidine, morpholine, N-methymorpholine, l,8-diazabicyclo[5.4.0]undec-7-ene, and dimethylethanolamine. It may be advantageous to concentrate the mixture or to add a solvent (or both) to maximize yield and optimize purity of the desired salt. Solvents suitable for this purpose include those in which the solubility of the desired salt is very low (such solvents are often called “anti-solvents”). Salts of L- glufosinate can be transformed into forms of glufosinate suitable for formulation by standard methods known to those skilled in the art. Alternatively, the L-glufosinate can be isolated as a zwitterion.

[0148] US 9,255,115 B2 describes how the hydrochloric acid salt of L-glufosinate can be converted to the zwitterionic form with a base such as sodium hydroxide or sodium methoxide and then crystallized from aqueous alcohol solvent to afford L-glufosinate in relatively high purity. This method has the advantage of producing crystalline L-glufosinate that is not hygroscopic and therefore maintains a higher purity compared to amorphous L-glufosinate when exposed to humidity over time.

[0149] Optionally, purification may be achieved by first crystallizing one or more impurities, removing the impurities by filtration and then further purifying L-glufosinate from the resulting filtrate by forming a salt as previously described. This is advantageous if unreacted amine donor can be partially or completely isolated and used in subsequent reactions. Similarly, unreacted PPO that is partially or completely isolated may be recycled for use in subsequent reactions.

[0150] Extraction may be used to purify the product. DE 3920570 C2 describes a process in which excess glutamic acid (used as the amine donor) is precipitated by adjusting the solution pH to 3.7 to 4.2 with sulfuric acid. After filtering the glutamic acid, the filtrate pH is lowered to 1-2 whereupon other impurities are extracted into a solvent. After extraction and concentration, ammonia is added to the aqueous solution to a pH of 5-7 whereupon ammonium sulfate precipitates. The ammonium sulfate is removed by filtration and the resulting filtrate is concentrated to afford the ammonium salt of L-glufosinate.

[0151] Isolation of L-glufosinate or its salts may be desirable, for example, for the purpose of shipping solids to the location of formulation or use. Typical industrial methods of isolation may be used, for example, a filtration, centrifugation, etc. Isolated product often requires the removal of water, volatile impurities and solvents (if present) and typical industrial drying equipment may be used for this purpose. Examples of such equipment include ovens, rotating drum dryers, agitated dryers, etc. In some cases, it may be advantageous to use a spray dryer.

[0152] It is not necessary to produce a solid product after purification. This may be advantageous if the formulation of L-glufosinate is to occur at the same site used for L-glufosinate production. L-glufosinate and many of its salts are readily soluble in water, and water is a convenient liquid to use for formulating products. For example, the amine donor is isolated by filtration and the resulting filtrate is concentrated by distillation. The pH of the filtrate may be adjusted to a desirable value and the resulting solution may be used as is or blended with formulation ingredients. In another example, a slurry of L-glufosinate or one of its salts may be prepared as described above and isolated by filtration. The solid could be dissolved directly on the filter by adding water or a suitable solvent to obtain a solution of L-glufosinate.

[0153] Composition according to the invention

[0154] The present invention further relates to a composition according to the present invention comprising 2-oxo-4-(hydroxy(methyl)phosphinoyl)butyric acid (PPO) according to formula (IV)

[0155] (IV), and aditionally a diol according to formula (III) and L-glufosinate.

[0156] Preferably, the composition further comprises a hydroxymethyl ketone according to formula (V):

[0157] (V).

[0158] Preferably, L-glufosinate is the predominant compound among L-glufosinate, PPO, and diol according to formula (III). For example, L-glufosinate can be present in the composition according to the present invention in an amount of at least 80 wt.-% of the sum of L- glufosinate, PPO, and diol according to formula (III), at least 85 wt.-% of the sum of L- glufosinate, PPO, and diol according to formula (III), at least 90 wt.-% of the sum of L- glufosinate, PPO, and diol according to formula (III), at least 95 wt.-% of the sum of L- glufosinate, PPO, and diol according to formula (III), at least 96 wt.-% of the sum of L- glufosinate, PPO, and diol according to formula (III), at least 97 wt.-% of the sum of L- glufosinate, PPO, and diol according to formula (III), at least 98 wt.-% of the sum of L- glufosinate, PPO, and diol according to formula (III), or at least 99 wt.-% of the sum of L- glufosinate, PPO, and diol according to formula (III). The composition according to the present invention can include PPO in an amount up to 20 wt.- wt.-% of the sum of L-glufosinate, PPO, and diol according to formula (III).

[0159] Optionally, the composition according to the present invention includes from 0.001 wt.-% to 20 wt.-% PPO (e.g., from 0.05 wt.-% to 15 wt.-% or from more than 0.01 wt.-% to less than 5 wt.-% PPO). For example, the composition according to the present invention can include PPO in an amount of less than 20 wt.-%, less than 19 wt.-%, less than 18 wt.-%, less than 17 wt.-%, less than 16 wt.-%, less than 15 wt.-%, less than 14 wt.-%, less than 13 wt.-%, less than 12 wt.-%, less than 11 wt.-%, less than 10 wt.-%, less than 9 wt.-%, less than 8 wt.-%, less than 7 wt.-%, less than 6 wt.-%, less than 5 wt.-%, less than 4 wt.-%, less than 3 wt.-%, less than 2 wt.-%, less than 1 wt.-%, less than 0.5 wt.-%, less than 0.1 wt.-%, or less than 0.01 wt.- wt.-% of the sum of the masses of L-glufosinate, PPO, and diol according to formula (III).

[0160] The diol according to formula (III) can be present in the composition according to the present invention in an amount of 15 wt.-% or less of the sum of L-glufosinate, PPO, and diol according to formula (III). For example, diol according to formula (III) can be present in an amount of 14 wt.-% or less, 13 wt.-% or less, 12 wt.-% or less, 11 wt.-% or less, 10 wt.-% or less, 9 wt.-% or less, 8 wt.-% or less, 7 wt.-% or less, 8 wt.-% or less, 6 wt.-% or less, 5 wt.-% or less, 4 wt.-% or less, 3 wt.-% or less, 2 wt.-% or less, 1 wt.-% or less, or 0.5 wt.-% or less of the sum of L-glufosinate, PPO, and diol according to formula (III).

[0161] In some embodiments, the composition according to the present invention can contain small amounts (e.g., about 10 wt.-% or less, about 8 wt.-% or less, about 5 wt.-% or less, about 2 wt.-% or less, or about 1 wt.-% or less of the composition according to the present invention) of diol according to formula (III). In some embodiments, the composition according to the present invention can contain small amounts (e.g., about 15 wt.-% or less, about 10 wt.-% or less, about 8 wt.-% or less, about 5 wt.-% or less, about 2 wt.-% or less, or about 1 wt.-% or less of the composition according to the present invention) of PPO.

[0162] The composition according to the present invention described herein is useful for application to a field of crop plants for the prevention or control of weeds. The composition according to the present invention may be formulated as a liquid for spraying on a field. The L-glufosinate is provided in the composition according to the present invention in effective amounts. As used herein, effective amount means from about 10 g active ingredient per hectare to about 1,500 g active ingredient per hectare, e.g., from about 50 g to about 400 g or from about 100 g to about 350 g. In some embodiments, the active ingredient is L- glufosinate. For example, the amount of L-glufosinate in the composition according to the present invention can be about 10 g, about 50 g, about 100 g, about 150 g, about 200 g, about 250 g, about 300 g, about 350 g, about 400 g, about 500 g, about 550 g, about 600 g, about 650 g, about 700 g, about 750 g, about 800 g, about 850 g, about 900 g, about 950 g, about 1,000 g, about 1,050 g, about 1,100 g, about 1,150 g, about 1,200 g, about 1,250 g, about 1,300 g, about 1,350 g, about 1,400 g, about 1,450 g, or about 1,500 g L-glufosinate per hectare.

[0163] The herbicidal composition according to the present invention (including concentrates which require dilution prior to application to the plants) described herein contains L- glufosinate (i.e., the active ingredient), optionally some residual diol according to formula (III) and / or PPO, and one or more adjuvant components in liquid or solid form.

[0164] The composition according to the present invention is prepared by admixing the active ingredient with one or more adjuvants, such as diluents, extenders, carriers, surfactants, organic solvents, humectants, or conditioning agents, to provide a composition according to the present invention in the form of a finely-divided particulate solid, pellet, solution, dispersion, or emulsion. Thus, the active ingredient can be used with an adjuvant, such as a finely-divided solid, a liquid of organic origin, water, a wetting agent, a dispersing agent, an emulsifying agent, or any suitable combination of these. From the viewpoint of economy and convenience, water is the preferred diluent. However, not all the compounds are resistant to hydrolysis and in some cases this may dictate the use of non-aqueous solvent media, as understood by those of skill in the art.

[0165] Optionally, one or more additional components can be added to the composition according to the present invention to produce a formulated herbicidal composition according to the present invention. Such formulated composition according to the present invention can include L-glufosinate, carriers (e.g., diluents and / or solvents), and other components. The formulated composition according to the present invention includes an effective amount of L-glufosinate. Optionally, the L-glufosinate can be present in the form of L-glufosinate ammonium. The L-glufosinate ammonium can be present in an amount ranging from 10 % to 30 wt.-% of the formulated composition according to the present invention. For example, the L-glufosinate ammonium can be present in an amount of 10 wt.-%, 12 wt.-%, 14 wt.-%, 16 wt.-%, 18 wt.-%, 20 wt.-%, 22 wt.-%, 24 wt.-%, 26 wt.-%, 28 wt.-%, or 30 wt.-% of the formulated composition according to the present invention. Optionally, the L-glufosinate ammonium is present in an amount of 12.25 wt.-% or of 24.5%

[0166] In some examples, the formulated composition according to the present invention can include one or more surfactants. A suitable surfactant for use in the formulated composition according to the present invention includes sodium alkyl ether sulfate. The surfactant can be present in an amount from 10 wt.-% to 40 wt.-% of the formulated composition according to the present invention. For example, the surfactant can be present in an amount of 10 wt.- %, 12 wt.-%, 14 wt.-%, 16 wt.-%, 18 wt.-%, 20 wt.-%, 22 wt.-%, 24 wt.-%, 26 wt.-%, 28 wt.-%, 30 wt.-%, 32 wt.-%, 34 wt.-%, 36 wt.-%, 38 wt.-%, or 40 wt.-% of the formulated composition according to the present invention. Optionally, the sodium alkyl ether sulfate is present in an amount of 11.05%, 15.8 wt.-%, 22.1%, or 31.6 wt.-%.

[0167] The formulated composition according to the present invention can optionally include one or more solvents (e.g., organic solvents). Optionally, the solvent can be l-methoxy-2-propanol, dipropylene glycol, ethylene glycol, and mixtures thereof. The one or more solvents can be present in an amount ranging from 0.5 % to 20 wt.-% of the formulated composition according to the present invention. For example, the total amount of solvents in the composition according to the present invention can be present in an amount of 0.5% to 18 wt.-%, 5 wt.-% to 15 wt.-%, or 7.5 wt.-% to 10 wt.-% of the formulated composition according to the present invention.

[0168] Optionally, the solvent includes a combination of two solvents. For example, the solvents in the formulation can include l-methoxy-2-propanol and dipropylene glycol. The 1-methoxy- 2-propanol can be present, for example, in an amount of 0.5 wt.-% to 2 wt.-% of the formulated composition according to the present invention. For example, the l-methoxy-2- propanol can be present in the amount of 0.5 wt.-%, 0.6 wt.-%, 0.7 wt.-%, 0.8 wt.-%, 0.9 wt.- %, 1.0 wt.-%, 1.1 wt.-% 1.2 wt.-%, 1.3 wt.-%, 1.4 wt.-%, 1.5 wt.-%, 1.6 wt.-%, 1.7 wt.-%, 1.8 wt.-%, 1.9 wt.-%, or 2.0 wt.-% of the formulated composition according to the present invention. Optionally, the l-methoxy-2-propanol is present in an amount of 0.5 wt.-% or 1.0 wt.-% of the formulated composition according to the present invention. The dipropylene glycol can be present in an amount of from 4 wt.-% to 18 wt.-% of the formulated composition according to the present invention. For example, the dipropylene glycol can be present in an amount of 4 wt.-%, 6 wt.-%, 8 wt.-%, 10 wt.-%, 12 wt.-%, 14 wt.-%, 16 wt.-%, or 18 wt.-% of the formulated composition according to the present invention. Optionally, the dipropylene glycol is present in an amount of 4.3 wt.-% or 8.6 wt.-% of the formulated composition according to the present invention.

[0169] The formulated composition according to the present invention can also include one or more polysaccharide humectants. Examples of suitable polysaccharide humectants include, for example, alkyl polysaccharides, pentoses, high fructose corn syrup, sorbitol, and molasses. The polysaccharide humectant, such as alkyl polysaccharide, can be present in the formulated composition according to the present invention in an amount ranging from 4 wt.-% to 20 wt.-% of the formulated composition according to the present invention. For example, the total amount of polysaccharide humectant in the composition according to the present invention can be present in an amount of 4 wt.-% to 18 wt.-%, 4.5 wt.-% to 15 wt.-%, or 5 wt.-% to 10 wt.-% of the formulated composition according to the present invention. In some examples, the total amount of polysaccharide humectant, such as the alkyl polysaccharide, present in the formulated composition according to the present invention can be 4 wt.-%, 5 wt.-%, 6 wt.-%, 7 wt.-%, 8 wt.-%, 9 wt.-%, 10 wt.-%, 11 wt.-%, 12 wt.-%, 13 wt.-%, 14 wt.-%, 15 wt.-%, 16 wt.-%, 17 wt.-%, or 18 wt.-%. Optionally, the alkyl polysaccharide can be present in an amount of 3.2%, 4.9 wt.-%, 6.2%, or 9.8 wt.-%.

[0170] A diluent can also be included in the formulated composition according to the present invention. Suitable diluents include water and other aqueous components. Optionally, the diluents are present in an amount necessary to produce composition according to the present invention ready for packaging or for use.

[0171] The herbicidal composition according to the present invention described herein, particularly liquids and soluble powders, can contain as further adjuvant components one or more surface-active agents in amounts sufficient to render a given composition according to the present invention readily dispersible in water or in oil. The incorporation of a surface-active agent into the composition according to the present invention greatly enhances its efficacy. Surface-active agent, as used herein, includes wetting agents, dispersing agents, suspending agents, and emulsifying agents are included therein. Anionic, cationic, and nonionic agents can be used with equal facility.

[0172] Suitable wetting agents include alkyl benzene and alkyl naphthalene sulfonates, sulfated fatty alcohols, amines or acid amides, long chain acid esters of sodium isothionate, esters of sodium sulfosuccinate, sulfated or sulfonated fatty acid esters petroleum solfonates, sulfonated vegetable oils, ditertiary acetylenic glycols, polyoxyethylene derivatives of alkylphenols (particularly isooctylphenol and nonylphenol), and polyoxethylene derivatives of the mono-higher fatty acid esters of hexitol anhydrides (e.g. sorbitan). Exemplary dispersants include methyl cellulose, polyvinyl alcohol, sodium lignin sulfonates, polymeric alkyl naphthalene sulfonates, sodium naphthalene sulfonate, polymethylene bisnaphthalenesulfonate, and sodium N-methyl-N- (long chain acid) laurates.

[0173] Water-dispersible powder composition according to the present invention can be made containing one or more active ingredients, an inert solid extender, and one or more wetting and dispersing agents. The inert solid extenders are usually of mineral origin, such as the natural clays, diatomaceous earth, and synthetic minerals derived from silica and the like. Examples of such extenders include kaolinites, attapulgite clay, and synthetic magnesium silicate. Water-dispersible powders described herein can optionally contain from about 5 to about 95 parts by weight of active ingredient (e.g., from about 15 to 30 parts by weight of active ingredient), from about 0.25 to 25 parts by weight of wetting agent, from about 0.25 to 25 parts by weight of dispersant, and from 4.5 to about 94.5 parts by weight of inert solid extender, all parts being by weight of the total composition according to the present invention. Where required, from about 0.1 to 2.0 parts by weight of the solid inert extender can be replaced by a corrosion inhibitor or anti-foaming agent or both.

[0174] Aqueous suspensions can be prepared by dissolution or by mixing together and grinding an aqueous slurry of a water-insoluble active ingredient in the presence of a dispersing agent to obtain a concentrated slurry of very finely divided particles. The resulting concentrated aqueous suspension is characterized by its extremely small particle size, so that when diluted and sprayed, coverage is very uniform.

[0175] Emulsifiable oils are usually solutions of active ingredient in water-immiscible or partially water-immiscible solvents together with a surface-active agent. Suitable solvents for the active ingredient described herein include hydrocarbons and water-immiscible ethers, esters, or ketones. The emulsifiable oil composition according to the present invention generally contains from about 5 to 95 parts active ingredient, about 1 to 50 parts surface active agent, and about 4 to 94 parts solvent, all parts being by weight based on the total weight of emulsifiable oil.

[0176] Compositions described herein can also contain other additaments, for example, fertilizers, phytotoxicants and plant growth regulants, pesticides, and the like used as adjuvants or in combination with any of the above-described adjuvants. The composition according to the present invention described herein can also be admixed with the other materials, e.g., fertilizers, other phytotoxicants, etc., and applied in a single application.

[0177] In each of the formulation types described herein, e.g., liquid and solid formulations, the concentration of the active ingredients are the same.

[0178] In some embodiments, the composition according to the present invention can include a - ketoglutarate as the major component, a -ketoglutarate is an important dicarboxylic acid and one of the key intermediates in the tricarboxylic acid cycle and amino acid metabolism. a -ketoglutarate can be isolated from the reaction mixture by methods such as that set forth in French Patent No. 07199, herein incorporated by reference. The a -ketoglutarate composition according to the present invention can be formulated with pharmaceutical excipients and carriers, food additives, or components used to form biomaterials. The a - ketoglutarate composition according to the present invention can be used in a variety of applications, including in synthesizing pharmaceutical agents, food additives, and biomaterials, as described in Li et al., Bioprocess Biosyst Eng, 39:967-976 (2016).

[0179] It is recognized that the herbicidal composition according to the present invention can be used in combination with other herbicides. The herbicidal composition according to the present invention of the present invention is often applied in conjunction with one or more other herbicides to control a wider variety of undesirable vegetation. When used in conjunction with other herbicides, the presently claimed compounds can be formulated with the other herbicide or herbicides, tank mixed with the other herbicide or herbicides or applied sequentially with the other herbicide or herbicides. Some of the herbicides that can be employed in conjunction with the compounds of the present invention include: amide herbicides such as allidochlor, beflubutamid, benzadox, benzipram, bromobutide, cafenstrole, CDEA, chlorthiamid, cyprazole, dimethenamid, dimethenamid-P, diphenamid, epronaz, etnipromid, fentrazamide, flupoxam, fomesafen, halosafen, isocarbamid, isoxaben, napropamide, naptalam, pethoxamid, propyzamide, quinonamid and tebutam; anilide herbicides such as chloranocryl, cisanilide, clomeprop, cypromid, diflufenican, etobenzanid, fenasulam, flufenacet, flufenican, mefenacet, mefluidide, metamifop, monalide, naproanilide, pentanochlor, picolinafen and propanil; arylalanine herbicides such as benzoylprop, flamprop and flamprop-M; chloroacetanilide herbicides such as acetochlor, alachlor, butachlor, butenachlor, delachlor, diethatyl, dimethachlor, metazachlor, metolachlor, S-metolachlor, pretilachlor, propachlor, propisochlor, prynachlor, terbuchlor, thenylchlor and xylachlor; sulfonanilide herbicides such as benzofluor, perfluidone, pyrimisulfan and profluazol; sulfonamide herbicides such as asulam, carbasulam, fenasulam and oryzalin; antibiotic herbicides such as bilanafos; benzoic acid herbicides such as chloramben, dicamba, 2,3,6-TBA and tricamba; pyrimidinyloxybenzoic acid herbicides such as bispyribac and pyriminobac; pyrimidinylthiobenzoic acid herbicides such as pyrithiobac; phthalic acid herbicides such as chlorthal; picolinic acid herbicides such as aminopyralid, clopyralid and picloram; quinolinecarboxylic acid herbicides such as quinclorac and quinmerac; arsenical herbicides such as cacodylic acid, CMA, DSMA, hexaflurate, MAA, MAMA, MSMA, potassium arsenite and sodium arsenite; benzoylcyclohexanedione herbicides such as mesotrione, sulcotrione, tefuryltrione and tembotrione; benzofuranyl alkylsulfonate herbicides such as benfuresate and ethofumesate; carbamate herbicides such as asulam, carboxazole chlorprocarb, dichlormate, fenasulam, karbutilate and terbucarb; carbanilate herbicides such as barban, BCPC, carbasulam, carbetamide, CEPC, chlorbufam, chlorpropham, CPPC, desmedipham, phenisopham, phenmedipham, phenmedipham-ethyl, propham and swep; cyclohexene oxime herbicides such as alloxydim, butroxydim, clethodim, cloproxydim, cycloxydim, profoxydim, sethoxydim, tepraloxydim and tralkoxydim; cyclopropylisoxazole herbicides such as isoxachlortole and isoxaflutole; dicarboximide herbicides such as benzfendizone, cinidon-ethyl, flumezin, flumiclorac, flumioxazin and flumipropyn; dinitroaniline herbicides such as benflu ralin, butralin, dinitramine, ethalfluralin, fluchloralin, isopropalin, methalpropalin, nitralin, oryzalin, pendimethalin, prodiamine, prof luralin and trifluralin; dinitrophenol herbicides such as dinofenate, dinoprop, dinosam, dinoseb, dinoterb, DNOC, etinofen and medinoterb; diphenyl ether herbicides such as ethoxyfen; nitrophenyl ether herbicides such as acifluorfen, aclonifen, bifenox, chlomethoxyfen, chlomitrofen, etnipromid, fluorodifen, fluoroglycofen, fluoronitrofen, fomesafen, furyloxyfen, halosafen, lactofen, nitrofen, nitrofluorfen and oxyfluorfen; dithiocarbamate herbicides such as dazomet and metam; halogenated aliphatic herbicides such as alorac, chloropon, dalapon, flupropanate, hexachloroacetone, iodomethane, methyl bromide, monochloroacetic acid, SMA and TCA; imidazolinone herbicides such as imazamethabenz, imazamox, imazapic, imazapyr, imazaquin and imazethapyr; inorganic herbicides such as ammonium sulfamate, borax, calcium chlorate, copper sulfate, ferrous sulfate, potassium azide, potassium cyanate, sodium azide, sodium chlorate and sulfuric acid; nitrile herbicides such as bromobonil, bromoxynil, chloroxynil, dichlobenil, iodobonil, ioxynil and pyraclonil; organophosphorus herbicides such as amiprofos-methyl, anilofos, bensulide, bilanafos, butamifos, 2,4-DEP, DMPA, EBEP, fosamine, glyphosate and piperophos; phenoxy herbicides such as bromofenoxim, clomeprop, 2,4-DEB, 2,4-DEP, difenopenten, disul, erbon, etnipromid, fenteracol and trifopsime; phenoxyacetic herbicides such as 4-CPA, 2,4-D, 3,4-DA, MCPA, MCPA-thioethyl and 2,4,5-T; phenoxybutyric herbicides such as 4-CPB, 2,4-DB, 3,4-DB, MCPB and 2,4,5-TB; phenoxypropionic herbicides such as cloprop, 4-CPP, dichlorprop, dichlorprop-P, 3,4-DP, fenoprop, mecoprop and mecoprop-P; aryloxyphenoxypropionic herbicides such as chlorazifop, clodinafop, clofop, cyhalofop, diclofop, fenoxaprop, fenoxaprop-P, fenthiaprop, fluazifop, fluazifop-P, haloxyfop, haloxyfop-P, isoxapyrifop, metamifop, propaquizafop, quizalofop, quizalofop-P and trifop; phenylenediamine herbicides such as dinitramine and prodiamine; pyrazolyl herbicides such as benzofenap, pyrazolynate, pyrasulfotole, pyrazoxyfen, pyroxasulfone and topramezone; pyrazolylphenyl herbicides such as fluazolate and pyraflufen; pyridazine herbicides such as credazine, pyridafol and pyridate; pyridazinone herbicides such as brompyrazon, chloridazon, dimidazon, flufenpyr, metflurazon, norflurazon, oxapyrazon and pydanon; pyridine herbicides such as aminopyralid, cliodinate, clopyralid, dithiopyr, fluroxypyr, haloxydine, picloram, picolinafen, pyriclor, thiazopyr and triclopyr; pyrimidinediamine herbicides such as iprymidam and tioclorim; quaternary ammonium herbicides such as cyperquat, diethamquat, difenzoquat, diquat, morfamquat and paraquat; thiocarbamate herbicides such as butylate, cycloate, di-allate, EPTC, esprocarb, ethiolate, isopolinate, methiobencarb, molinate, orbencarb, pebulate, prosulfocarb, pyributicarb, sulfallate, thiobencarb, tiocarbazil, tri-allate and vernolate; thiocarbonate herbicides such as dimexano, EXD and proxan; thiourea herbicides such as methiuron; triazine herbicides such as dipropetryn, triaziflam and trihydroxytriazine; chlorotriazine herbicides such as atrazine, chlorazine, cyanazine, cyprazine, eglinazine, ipazine, mesoprazine, procyazine, proglinazine, propazine, sebuthylazine, simazine, terbuthylazine and trietazine; methoxytriazine herbicides such as atraton, methometon, prometon, secbumeton, simeton and terbumeton; methylthiotriazine herbicides such as ametryn, aziprotryne, cyanatryn, desmetryn, dimethametryn, methoprotryne, prometryn, simetryn and terbutryn; triazinone herbicides such as ametridione, amibuzin, hexazinone, isomethiozin, metamitron and metribuzin; triazole herbicides such as amitrole, cafenstrole, epronaz and flupoxam; triazoIone herbicides such as amicarbazone, bencarbazone, carfentrazone, flucarbazone, propoxycarbazone, sulfentrazone and thiencarbazone-methyl; triazolopyrimidine herbicides such as cloransulam, diclosulam, florasulam, flumetsulam, metosulam, penoxsulam and pyroxsulam; uracil herbicides such as butafenacil, bromacil, flupropacil, isocil, lenacil and terbacil; 3-phenyluracils; urea herbicides such as benzthiazuron, cumyluron, cycluron, dichloralurea, diflufenzopyr, isonoruron, isouron, methabenzthiazuron, monisouron and noruron; phenylurea herbicides such as anisuron, buturon, chlorbromuron, chloreturon, chlorotoluron, chloroxuron, daimuron, difenoxuron, dimefuron, diuron, fenuron, fluometuron, fluothiuron, isoproturon, linuron, methiuron, methyldymron, metobenzuron, metobromuron, metoxuron, monolinuron, monuron, neburon, parafluron, phenobenzuron, siduron, tetrafluron and thidiazuron; pyrimidinylsulfonylurea herbicides such as amidosulfuron, azimsulfuron, bensulfuron, chlorimuron, cyclosulfamuron, ethoxysulfuron, flazasulfuron, flucetosulfuron, flupyrsulfuron, foramsulfuron, halosulfuron, imazosulfuron, mesosulfuron, nicosulfuron, orthosulfamuron, oxasulfuron, primisulfuron, pyrazosulfuron, rimsulfuron, sulfometuron, sulfosulfuron and trif loxysu Ifu ron ; triazi nylsu Ifonyl u rea herbicides such as chlorsulfuron, cinosulfuron, ethametsulfuron, iodosulfuron, metsulfuron, prosulfuron, thifensulfuron, triasulfuron, tribenuron, trif I us u If u ro n and tritosulfuron; thiadiazolylurea herbicides such as buthiuron, ethidimuron, tebuthiuron, thiazafluron and thidiazuron; and unclassified herbicides such as acrolein, allyl alcohol, aminocyclopyrachlor, azafenidin, benazolin, bentazone, benzobicyclon, buthidazole, calcium cyanamide, cambendichlor, chlorfenac, chlorfenprop, chlorflurazole, chlorflurenol, cinmethylin, clomazone, CPMF, cresol, ortho-dichlorobenzene, dimepiperate, endothal, fluoromidine, fluridone, flurochloridone, flurtamone, fluthiacet, indanofan, methazole, methyl isothiocyanate, nipyraclofen, OCH, oxadiargyl, oxadiazon, oxaziclomefone, pentachlorophenol, pentoxazone, phenylmercury acetate, pinoxaden, prosulfalin, pyribenzoxim, pyriftalid, quinoclamine, rhodethanil, sulglycapin, thidiazimin, tridiphane, trimeturon, tripropindan and tritac. The herbicidal composition according to the present invention of the present invention can, further, be used in conjunction with glyphosate or 2,4-D on glyphosate-tolerant or 2,4-D-tolerant crops. It is generally preferred to use the composition according to the present invention of the invention in combination with herbicides that are selective for the crop being treated and which complement the spectrum of weeds controlled by these compositions according to the present invention at the application rate employed. It is further generally preferred to apply the composition according to the present invention of the invention and other complementary herbicides at the same time, either as a combination formulation or as a tank.

[0180] Method according to the invention

[0181] The present invention is concerned with a method of selectively controlling weeds in an area comprising a crop of planted seeds or crops that are resistant to glufosinate using a composition comprising 2-oxo-4-(hydroxy(methyl)phosphinoyl)butyric acid (PPO) according to formula (IV)

[0182] (IV), and aditionally a diol according to formula (III)

[0183] (Ill), and L-glufosinate.

[0184] Preferably, the composition further comprises a hydroxymethyl ketone according to formula (V):

[0185] Hence, the composition according to the present invention can be used in methods for selectively controlling weeds in a field or any other area, including, for example, a railway, lawn, golf course, and others where the control of weeds is desired. Optionally, the field or other area can contain a crop of planted seeds or crops that are resistant to glufosinate. The methods can include applying an effective amount of a composition comprising L- glufosinate as described herein to the field.

[0186] The composition according to the present invention are useful for application to a field of crop plants for the prevention or control of weeds. The composition may be formulated as a liquid for spraying on a field. The L-glufosinate is provided in the composition in effective amounts. As used herein, effective amount means from about 10 g active ingredient per hectare to about 1,500 g active ingredient per hectare, e.g., from about 50 g to about 400 g or from about 100 g to about 350 g. In some embodiments, the active ingredient is L- glufosinate. For example, the amount of L-glufosinate in the composition can be about 10 g, about 50 g, about 100 g, about 150 g, about 200 g, about 250 g, about 300 g, about 350 g, about 400 g, about 500 g, about 550 g, about 600 g, about 650 g, about 700 g, about 750 g, about 800 g, about 850 g, about 900 g, about 950 g, about 1,000 g, about 1,050 g, about 1,100 g, about 1,150 g, about 1,200 g, about 1,250 g, about 1,300 g, about 1,350 g, about 1,400 g, about 1,450 g, or about 1,500 g L-glufosinate per hectare.

[0187] Experimental Part

[0188] Inventive Example I El: Addition of MPE

[0189] To 6 g methylphosphinic acid butyl ester (MPE) was added 5 ml toluene under stirring at room temperature followed by 20 mg 2,2’-azobis(isobutyronitrile) (AIBN). The reaction mixture was heated to 65 ° C. A solution of 2.0 g 3,4-diacetoxy-l-butene in 5 ml_ toluene was added to the reaction mixture. The addition was carried out dropwise over 30 min.

[0190] After the addition had been finished, the temperature was increased to 75 ° C and the reaction mixture was stirred for additional 5 h. Toluene was removed under reduced pressure on a rotary evaporator. Excess MPE was distilled off at a pressure below 1 mbar and a temperature above 60 ° C. The distillation sump contained the pure product (3.3 g, 92%).XH NMR analysis (400 MHz, Chloroform-d) revealed <5 5.13 - 5.03 (m, 1H), 4.29 - 4.20 (m, 1H), 4.11 - 3.91 (m, 3H), 2.08 (s, 3H), 2.07 (s, 3H), 1.99 - 1.58 (m, 6H), 1.47 (d, J = 13.6 Hz, 3H), 1.44 - 1.35 (m, 2H), 0.94 (t, J = 7.4 Hz, 3H).

[0191] Inventive Example IE2: Deprotection

[0192] 80 mL of aq. HCI (17% w / w) were added to a mixture of 1 g of starting material as prepared according to I El. The reaction mixture was stirred at 100 ° C for 24 h and concentrated in vacuo yielding 505 mg of product diol. JH NMR analysis (400 MHz, Deuterium Oxide) revealed <5 3.74 - 3.68 (m, 1H), 3.64 - 3.56 (m, 1H), 3.55 - 3.46 (m, 1H), 2.02 - 1.47 (m, 7H). LC-MS found 169.1 (M + H) +

[0193] Inventive Example IE3: Addition of MPE to carbonate

[0194] To 49.8 g methylphosphinic acid butyl ester (MPE) was added 50 ml toluene under stirring at room temperature followed by 120 mg 2,2’-azobis(isobutyronitrile) (AIBN). The reaction mixture was heated to 75 ° C. A solution of 11.0 g 4-vinyl-l,3-dioxolan-2-one (vinyl ethylene carbonate, CAS 4427-96-7) in 30 mL toluene was added to the reaction mixture. The addition was carried out dropwise over 60 min. The reaction mixture was stirred at 75 ° C for an additional 7 h. Excess MPE was distilled off at a pressure below 1 mbar and a temperature above 60 ° C using a thin film evaporator. The distillation sump contained the product and was further purified by column chromatography using Methanol / Dichloromethane (22.0 g , 91%).XH NMR analysis (400 MHz, Chloroform-d) revealed <5 4.90 - 4.77 (m, 1H), 4.63 - 4.53 (m, 1H), 4.17 - 4.07 (m, 1H), 4.07 - 3.91 (m, 2H), 2.15 - 1.72 (m, 4H), 1.72 - 1.59 (m, 2H), 1.59 - 1.46 (m, 3H), 1.45 - 1.33 (m, 2H), 0.95 (t, J = 7.4 Hz, 3H).

[0195] Inventive Example IE4: Deprotection of carbonate

[0196] 100 mL of aq. HCI (20% w / w) were added to a mixture of 16.5 g of starting material as prepared according to IE3. The reaction mixture was stirred at 90 ° C for 4 h and concentrated in vacuo yielding the product diol. Inventive Example IE5: Chemical oxidation of diol

[0197] 1 M NaOH was added to a solution of 2-hydroxy-4-(hydroxy(methyl)phosphinoyl)butanol (100 mg) in water (6 mL) to adjust the pH to 8. 500 mg Pt / Bi on carbon (water content 59%, 1.63% Pt, 0.41% Bi) were added. The reaction mixture was heated to 55 ° C and the pH was adjusted throughout the reaction to 8 by addition of aq. NaOH while aerating with oxygen. After 28 h NMR showed a conversion of 10% to the keto acid (PPO). PPO and intermediates were identified by both NMR and HPLC.

[0198] HPLC Method: The phosphorous containing compounds were separated by an Aminex HPX- 87 H, 300*7.8 mm column. Temperature 30 ° C, Flowrate 0.5 mL / min, Rl Detection, Eluent 5 mM sulfuric acid in water. HPLC retention times: 2-hydroxy-4- (hydroxy(methyl)phosphinoyl)butanol: 16.0 min, PPO 9.7 min,

[0199] Inventive Example IE6: Chemical oxidation of diol including Catalase

[0200] 1 M NaOH was added to a solution of 2-hydroxy-4-(hydroxy(methyl)phosphinoyl)butanol (100 mg) in water (6 mL) to adjust the pH to 8. 500 mg Pt / Bi on carbon (water content 59%, 1.63% Pt, 0.41% Bi) were added. Catalase (10 mg, CAS: 9001-05-2) was added to the reaction mixture. The reaction mixture was heated to 40 ° C and aerated. The pH value was adjusted throughout the reaction to 8 by addition of aq. NaOH. After 26 h a conversion of 59% to the keto acid (PPO) was measured by NMR.

[0201] Inventive Example IE7: Cloning of oxidoreductases and transaminase

[0202] Enzymes were identified from public databases (NCBI, Uniprot). The DNA sequences corresponding to the enzymes were codon-optimized for expression in Escherichia coli (E. coli) and cloned (Twist Bioscience) in pDHE 19.2 vector (DE 19848129). The gene of interest lies under control of a rhamnose inducible promoter (rhaBAD). The synthesized plasmids were used to transform competent cells (Chung, C.T. et al., Proc Natl Acad Sci U S A, 1989, 86, 2172) of the E. coli strain TG10 (WO 2004 / 050877 Al). The E. coli strain TG10 is a rhaA- -derivate of E. coli TGI (DSMZ 6056) transformed with pHSG575 (Takeshita, S. et al., Gene, 1987, 61, 63) and pAgro4 (pBB541 in Tomoyasu, T. et al., Mo / . Microbiol., 2001,

[0203] 40, 397). GalOx (SEQ ID NO:9) may be cloned and expressed as described in Birmingham, W.R., et al., Nature Communications, 2021, 12, 4946) or WO 2016 / 150629 Al. The sequences as listed in Table 1 were cloned based on the above-mentioned protocols.

[0204] Table 1: Tested Enzymes

[0205] Inventive Example IE8: Recombinant production of oxidases and transaminase

[0206] E. coli TG10 transformed with the oxidase-containing plasmids were grown in 10 ml LB medium (Bertani, G., J Bacterio / , 1951, 62, 293) supplemented with 100 pg / ml ampicillin, 50 pg / ml spectinomycin, 20 pg / ml chloramphenicol and 12.5 pg / ml tetracyline at 37 ° C for 16 h (200 rpm). This preculture was used to inoculate 100 ml of LB medium supplemented with 100 pg / ml ampicillin, 50 pg / ml spectinomycin, 20 pg / ml chloramphenicol and 12.5 pg / ml tetracyline until the optical density reaches A600 nm of 0.6. To the cultures, 0.2 mM isopropyl-E-D-thiogalactopyranoside, and 0.5 g / L rhamnose were added and incubated further at 22 ° C for 16-18 h (200 rpm). The biomass was harvested by centrifugation at 4000*g for 15 min at 4 C and the pellets were frozen in -20 ° C until further use. Recombinant production of GalOx (SEQ ID NO:10) is described in Birmingham, W.R., et al., Nature Communications, 2021, 12, 4946) or WO 2016 / 150629 Al. For Transaminase (SEQ ID NO:12): The cell suspension was frozen at -80 ° C before being lyophilized. In that regard, the lyophilizer was kept at -50 ° C and a pressure of 0.25 mbar. Lyophilized cells were stored at 4 ° C. Inventive Example IE9: Preparation of the biocatalyst for activity screening.

[0207] The frozen pellets were thawed in 0.1 M potassium phosphate buffer pH 7.8 (3 mL buffer / g pellet). The cell suspension was distributed in 2 ml vials and lyzed in Homogenisator (Precellys ®, VWR) for 2*30 sec cycles. The cell-free lysate was further centrifuged at 12000*g for 15 min at 4 ° C. The clarified supernatant (cell-free extract) was used for the activity assay.

[0208] Inventive Example I E10: ABTS assay - Activity screening of oxidoreductase

[0209] Enzymatic activity was measured at 30 ° C by incubating the cell-free extract (12.5 vol%) in 200 pl of 0.1 M potassium phosphate buffer pH 7.8 containing 5 g / L 2-hydroxy-4- (hydroxy(methyl)phosphinoyl)butanol, 0.2 g / L ABTS (2,2’-azino-bis(3-ethylbenzothiazoline- 6-sulfonic acid)) and 0.5 g / L HRP (Horse radish peroxidase). The reaction was monitored by measuring the absorbance of ABTSox at 420 nm up to 2 h. In the presence of GalOx- Protein (SEQ ID NO:10) 2-hydroxy-4-(hydroxy(methyl)phosphinoyl)butanol was oxidized. In the presence of Aoxl-Protein (SEQ ID NO:4) 2-hydroxy-4-

[0210] (hydroxy(methyl)phosphinoyl)butanol was oxidized. Whereas in the absence of protein no oxidation was observed.

[0211] Inventive Example IE11: One pot preparation of L-Glufosinate

[0212] 1 M aq. NaOH was added to a solution of 2-hydroxy-4-(hydroxy(methyl)phosphinoyl)butanol (100 mg) as prepared in IE2 in water (6 mL) to adjust the pH to 8. 500 mg Pt / Bi on carbon (water content 59%, 1.63% Pt, 0.41% Bi) were added. Catalase (10 mg, CAS: 9001-05-2) was added to the reaction mixture. The reaction mixture was heated to 40 ° C and aerated. The pH value was adjusted throughout the reaction to 8 by addition of aq. NaOH. After 20 h 22.5 pL 5 M aq Isopropylamine solution , 55 pL 10 mM Pyridoxalphosphat (“PLP”)-solution and 6 mg Transaminase (SEQ ID NO:12, lyophilized cells) were added. After an additional 26 h of stirring 55 pL 10 mM PLP-solution and 6 mg Transaminase (lyophilized cells) were added. After an additional 72 hours of stirring the reaction mixture contained L-Glufosinate, which was detected by both HPLC and NMR (Conversion yield in NMR 2.9%). The concentration of glufosinate was determined by HPLC using o-Phthaldehyde (OPA) as a precolumn derivatizing reagent. Precolumn: C18 ODS, Column: YMC Triart C18 plus, 150*4,6 mm column, temperature 40 ° C, flow rate 1.5 mL, detection fluescence FLD excitation 340 nm, emission 450 nM, eluent A 40 mM NaH2PO4(pH 7.8), Eluent B acetonitrile:methanol:water 45:45:10, gradient, retention time Glufosinate: 4.7 min. Min A% B%

[0213] 0.0 96.0 4.0

[0214] 2.0 96.0 4.0

[0215] 5.0 80.0 20.0

[0216] 9.0 0.0 100.0

[0217] Inventive Example IE12: PPO conversion to L-Glufosinate

[0218] To 4-[hydroxy(methyl)phosphoryl]-2-oxobutanoic acid (PPO, 1.08 g, 5.997 mmol) in water (10 mL) was added isopropylamine (1.202 g, 5.997 mmol, 1.0 eq, 5 M aq solution). The pH was adjusted to 8.5 using 10 M aq Ammonia solution and 15 mL water were added. The reaction mixture was heated to 35 ° C and pyridoxalphosphate-solution (PLP) (1.2 mL, 10 mM) and Transaminase (0.1 g, SEQ ID NO:12, lyophilized cells) were added. The reaction volume was adjusted to 30 using water and the pH was continuously adjusted to 8.5 using 10 M aq ammonia. After 23 hours 98.5% of PPO was converted to L-Glufosinate ammonium by HPLC.

[0219] Sequences

[0220] SEQ I D NO:1 atgagcgatattactgtgacgaattgggcgggtaacatcacctatacggcgaaagaactgctgcgtccgcacagcctgg acgcgctgcgcgcattggttgcagacagcgcgcgtgtccgcgtgctgggtagcggccatagctttaacgaaattgcggagccgg gtgatggcggcgtgctgctgtccctggccggtttgccatccgttgtcgacgtcgatactgcggcccgtacggtgcgtgtcggtggc ggcgttcgctacgcagagctggctcgtgtcgttcacgcgcgtggtttagcgctgccgaacatggccagcctgccgcacatcagcg ttgcgggcagcgtggcgaccggtacgcatggcagcggtgttggtaatggctctctggcgagcgtagttagagaagtggaactggt gacggcagatggcagcaccgtcgttatcgctcgtggcgacgagcgttttggtggcgcggttacgtcgctgggtgccctgggtgttg tcaccagcttgaccctggacctggagccggcatacgaaatggaacaacatgtttttaccgaactgccgctggctggcctggatcc ggcgaccttcgaaacggttatggcagctgcgtactccgtgtctctgtttaccgattggcgcgcaccgggttttcgccaagtctggtt gaagcgtcgtaccgaccgccctctggacggcttcccgtatgcagcaccggcggcggagaaaatgcacccggtgccgggtatgc cagccgttaattgcactgagcaattcggcgtgccgggtccgtggcacgagcgcctgccgcatttccgtgccgagttcaccccgag cagcggtgctgaactccagtcagagtacctgatgccgcgtgagcacgcgctggcagcactgcacgcgatggacgcgatccgtg aaaccctggctcctgtgttgcagacctgtgagattcgcaccgtggctgccgacgcacagtggctgagcccggcttatggtcgtga taccgtagccgcacattttacgtgggtcgaggacaccgccgcggtgctgccggttgttcgccgcctggaagaagcactggtcccg ttcgcggcacgtccgcactggggtaaagtgttcacggtcccggcaggcgagttgcgtgcgctgtacccgcgtcttgcggatttcgg tgcactggccggtgccctggacccagcgggcaagtttaccaacgcgttcgtccgtggtgtgctggcgggt

[0221] SEQ I D NO:2

[0222] MSDITVTNWAGNITYTAKELLRPHSLDALRALVADSARVRVLGSGHSFN EIAEPGDGGVLL SLAGLPSVVDVDTAARTVRVGGGVRYAELARVVHARGLALPNMASLPH ISVAGSVATGTHGSGV GNGSLASVVREVELVTADGSTVVIARGDERFGGAVTSLGALGVVTSLTLDLEPAYEMEQHVFTEL PLAGLDPATFETVMAAAYSVSLFTDWRAPGFRQVWLKRRTDRPLDGFPYAAPAAEKM HPVPG MPAVNCTEQFGVPGPWHERLPHFRAEFTPSSGAELQSEYLMPREHALAALHAMDAI RETLAPV LQTCEI RTVAADAQWLSPAYGRDTVAAHFTWVEDTAAVLPVVRRLEEALVPFAARPHWGKVFTV PAGELRALYPRLADFGALAGALDPAGKFTNAFVRGVLAG

[0223] SEQ I D NO:3 atgatgggtcatccggaagaggttgatgtcattgtgtgtggcggcggtccggctggttgcgtagttgcgggccgtctggcg tacgcggaccccaccctcaaggtgatgctgatcgaaggcggggcgaataaccgcgatgacccctgggtttatcgtccgggaatt tatgtacgcaacatgcagcggaacggcatcaatgataaagcgacgttctacacagacaccatggcgtcgagttatttgcgcggt cggagaagcatagtcccgtgtgccaacatcctggggggtggtagctcaattaacttccagatgtacactcgggcgtcagcgagc gattgggatgatttcaagacggaagggtggacgtgtaaggacctgttgcctctgatgaagcgtctggaaaattaccagaaaccgt gcaataacgatacccacggctatgacggtccgattgctattagcaatggcggccagatcatgcctgtggcgcaggatttccttag agcagcacacgctatcggggttccatattccgatgatattcaggatctgaccaccgctcatggtgcggagatttgggccaaatat atcaatcgccataccggtcgtcgcagtgatgcagctactgcctatgtgcacagtgtgatggacgtgcaagataatttatttctgcgt tgcaacgcacgcgtgtcacgcgtcttgttcgatgataacaataaagccgtgggcgtcgcctatgttccaagccgtaatcgtaccc atggcggtaaattacatgagaccatagtaaaagcgcgtaaaatggttgttctgagctctggcaccctcggcacaccgcaaatcct agagcgctcgggagttggtaatggagaactgctgcgccaactcggtattaaaatcgtttcggatctgccaggcgtcggtgaacag tatcaggaccactacaccacgctgagcatctatcgcgtctccaacgaatctattaccaccgatgatttcctgcgaggggtgaaag acgtacagcgtgaactgtttaccgaatgggaagtaagcccggaaaaagcccgtttatcttcgaatgcaattgacgccggctttaa aattcgccctacggaggaggaactgaaagaaatgggcccggagttcaacgagctgtggaaccgttactttaaagataaacccg ataaaccggtgatgtttggctctattgtcgcgggcgcttacgcagaccacactcttctaccgccgggtaaatatattacgatgtttc agtatttagaatatccggcaagccgcggcaaaattcatatcaaatcccaaaacccatacgtggaaccgttctttgacagcgggtt tatgaacaataaggcggattttgccccgatccgctggagctacaagaaaaccagggaagtggcgcgacgcatggacgcatttc gtggagaattaacgtcccaccatccgcgttttcaccccgcaagtccggccgcttgcaaagacatcgatattgaaacagccaagc agatctacccggatggactgacggttggtatccatatgggctcgtggcatcagccttccgaaccgtacaaacatgataaggtgat cgaggacataccatacacggaggaagatgataaagcgattgacgattgggtcgcggaccacgtcgaaactacctggcatagtc tgggtacttgtgccatgaaaccgcgtgaacaaggtggagtagttgataaacgtcttaacgtgtatggtactcaaaatttgaaatgc gtggacctgtcaatctgcccggataacctgggcacaaacacgtattctagcgcgttgctcgtaggggaaaaaggggccgatttg attgcagaagagcttggcttaaaaattaaaaccccacacgcccctgttccacatgctccagtgcccacaggccgccctgcgacc caacaggtgcgcggatcctga

[0224] SEQ I D NO:4

[0225] MGH PEEVDVIVCGGGPAGCVVAGRLAYADPTLKVMLIEGGANNRDDPWVYRPGIYVRNM QRNGINDKATFYTDTMASSYLRGRRSIVPCAN ILGGGSSINFQMYTRASASDWDDFKTEGWTCK DLLPLMKRLENYQKPCNNDTHGYDGPIAISNGGQIM PVAQDFLRAAHAIGVPYSDDIQDLTTAH GAEIWAKYINRHTGRRSDAATAYVHSVMDVQDN LFLRCNARVSRVLFDDN NKAVGVAYVPSRN RTHGGKLH ETIVKARKMVVLSSGTLGTPQILERSGVGNGELLRQLGIKIVSDLPGVGEQYQDHYT TLSIYRVSN ESITTDDFLRGVKDVQRELFTEWEVSPEKARLSSNAIDAGFKI RPTEEELKEMGPEF NELWNRYFKDKPDKPVMFGSIVAGAYADHTLLPPGKYITMFQYLEYPASRGKIHIKSQNPYVEP FFDSGFMNN KADFAPI RWSYKKTREVARRMDAFRGELTSHHPRFHPASPAACKDI DIETAKQIY PDGLTVGIH MGSWHQPSEPYKH DKVI EDI PYTEEDDKAIDDWVADHVETTWHSLGTCAMKPRE QGGVVDKRLNVYGTQNLKCVDLSICPDNLGTNTYSSALLVGEKGADLIAEELGLKIKTPHAPVPH APVPTGRPATQQVR

[0226] SEQ I D NO:5 atgtcaacctctagctctgacccgtttttcaattttgccaaatccagcttccgctctgcggctgcacagaaagcgagtgcat ctagtctgccgccgttgcccgggccggataaaaaagttccggggatggatattaaatatgatgtggttattgtcggatctggtccg attggttgcacgtacgctcgggagcttgttggtgcgggctataaagtcgctatgtttgatataggcgagatcgactcgggcctgaa aatcggcgcgcataaaaaaaacaccgtggagtaccagaaaaacattgataaattcgttaacgtaattcagggccagctcatgtc cgtttcggtgcctgtgaacaccctggtcgtggacactctcagcccgacgtcgtggcaggccagcacgttctttgtacgcaacggct caaacccagagcaggacccactgcgtaatctgtcaggccaagcggtaactcgcgtggtcggaggcatgagcacccactggac atgcgcaacgccccgcttcgatcgggaacagcgtccgctccttgtcaaagacgacgctgatgccgacgacgcggaatgggatc gtttgtacaccaaagccgaatcatattttcaaaccggtacggatcaatttaaagagtccatccgtcataatctggttctgaataaac tgaccgaggaatacaaaggtcagcgtgattttcagcagatcccgctggctgcgacccgccgctcgcctacttttgtcgaatggag ttccgcgaatacggtgtttgatttacaaaatcgtccgaacacggacgctccggaagaaagatttaacttattcccggccgtcgcct gtgagagggtggtacgcaatgcgttgaatagcgaaatcgaatccttacacatccatgacctaattagcggggaccgattcgaaa ttaaggccgatgtttacgtcttgaccgccggtgcggttcataatacccaattactggttaacagtggttttgggcagctgggccgcc ccaatcctgcgaacccgcctgaactgttaccgagcctcggtagctatattacggaacagtctcttgtgttctgtcagacggtgatg agcacagaattgattgattcggtgaagtcggatatgaccattcgtgggacacctggcgagctaacttatagtgtcacgtatacgcc cggcgcgagtaccaacaaacacccggattggtggaacgaaaaagttaagaaccacatgatgcaacatcaggaagatccgttg cccataccgtttgaagacccagaaccacaggtaaccaccctgttccaacctagccatccgtggcacacccaaatccaccgtgat gccttctcatacggtgcggtgcagcagtcgattgattcccggctgattgtagactggcgtttctttggccgtactgaaccgaaagag gagaacaaactgtggttctcggataagattactgacgcctacaatatgccgcagccgacctttgattttcgctttccggcaggccg tactagcaaagaagcggaagatatgatgacagatatgtgcgttatgtccgccaaaatcggtggatttctgccaggaagcctgcc gcagtttatggagccaggcctggtgctgcacctgggtggtacccatcgaatgggctttgatgaaaaggaagataattgttgcgtg aacactgacagccgcgtgtttgggtttaaaaatctgttccttggcggttgcggtaacatcccaaccgcatacggagcgaacccta cgctgacagcaatgtcattagcgatcaagtcctgtgaatatatcaagcaaaatttcaccccaagtccgttcacatctgaagcaca a

[0227] SEQ I D NO:6

[0228] MSTSSSDPFFN FAKSSFRSAAAQKASASSLPPLPGPDKKVPGMDI KYDVVIVGSGPIGCTY ARELVGAGYKVAMFDIGEI DSGLKIGAHKKNTVEYQKNIDKFVNVIQGQLMSVSVPVNTLVVDTL SPTSWQASTFFVRNGSNPEQDPLRNLSGQAVTRVVGGMSTHWTCATPRFDREQRPLLVKDDA DADDAEWDRLYTKAESYFQTGTDQFKESI RH NLVLN KLTEEYKGQRDFQQIPLAATRRSPTFVE WSSANTVFDLQNRPNTDAPEERFNLFPAVACERVVRNALNSEIESLHIHDLISGDRFEI KADVYV LTAGAVHNTQLLVNSGFGQLGRPNPAN PPELLPSLGSYITEQSLVFCQTVMSTELI DSVKSDMTI RGTPGELTYSVTYTPGASTNKHPDWWNEKVKNHMMQHQEDPLPIPFEDPEPQVTTLFQPSHP WHTQI HRDAFSYGAVQQSIDSRLIVDWRFFGRTEPKEEN KLWFSDKITDAYNMPQPTFDFRFPA GRTSKEAEDMMTDMCVMSAKIGGFLPGSLPQFMEPGLVLHLGGTHRMGFDEKEDNCCVNTD SRVFGFKNLFLGGCGNI PTAYGAN PTLTAMSLAIKSCEYI KQNFTPSPFTSEAQ

[0229] SEQ I D NO:7 atgagcacgtcgagcagtgatccgttctataatttcgcgaaaacgagctttaaatcagcggcggctcagaaagcctcag ccacaagtctgccgcctctccccggccccgaccagaaagtaccgggtatggatattaaatatgacgttgttattgtcggcagcgg cccgatcggttgcacctacgcgcgcgaactggtggaagcgggttataaagtggcgatgttcgacattggcgaaattgactcagg gcttaagatcggtgcgcataagaagaacaccgtcgagtatcaaaaaaatattgacaaatttgtcaatgttattcagggccaattg atgtctgtgtctgtaccggtaaataaactggttgtggataccttaagtccgaccagttggcaagcgtccacgtttttcgttcgcaatg gctcaaacccggagcaggacccgcttcggaatctgagcggccaggcagttactcgcgtggtgggtggcatgtctacgcactgga cgtgtgcaaccccgcggtttgatagggagcagcgtccactgctggtcaaagatgatccggatgccgatgatgcgatttgggacc agctgtatacgaaagcagaaagctattttaagaccgggacagatcagtttaacgaatctatacgtcataaccttgttttgaacaaa ttagctgaagaatataaaggtcagcgtacctttcagcagattccattggcggccacccgtcgcaacccgacttttgtggaatggtc gagcgccaatactgtgtttgatctgcaaaaccgcccgaatatcgacgcacccgaagaacgcttcaatctttttcctgcggtggcgt gtgagagagtaatgcgtaacgcctcaaataccgctattgaatcactgcatatccgggatctgatttccggtgatcgctttgctatcc aggcagatgtctatgtgctgaccgcgggagcggttcacaacacccaattactggttaattccggttttgggaagctgggccgtccg gacccggccaaccccccagaattactgcctttcttaggctcctacattacagagcagtccctggtcttttgccagaccgtaatgtct accgaactgatcgattcggtgaagtcggacatgacgattatcggtaaccctggcgaactgggctactcggtgtcttacatgccgg gtgcttcgactaacaaacacccagattggtggaatgagaaagtccagaaccacatgatgcaacaccaagaagacccgttacct attccatttgaagatccagaaccgcaagtgaccacgttgtttcagccgagccatccttggcatacacagatccatcgagatgcctt tagctacggtgccgtacagcaaagcattgatagccgtctgatagtcgattggcgctttttcggccgtaccgagcccaaagaggag aataaattgtggttcagtgacaaaattacggacgcctacaacatgccgcagccgactttcgacttccgcttcccagcaggacgta ccagtcaagaagctgaagatatgatgacggacatgtgcgttatgtccgcgaaaatcggtggctttctgccggggtccctgccgca atttatggaaccggggctagtcctccacctgggaggaactcatcgcatggggttcgacgaacaggaagataactgttgcgtggat acagatagccgtgtgttcggtttcaacaatctcttcctcggtggatgtggcaacatccccactgcatacggcgccaacccaacctt gacggcaatgagtctggcaatcaaatcgtgcgagtatatcaaaaaaaattttacccctagcccgtttaccccagctcaatga

[0230] SEQ I D NO:8

[0231] MSTSSSDPFYNFAKTSFKSAAAQKASATSLPPLPGPDQKVPGMDI KYDVVIVGSGPIGCTY ARELVEAGYKVAM FDIGEIDSGLKIGAHKKNTVEYQKNIDKFVNVIQGQLMSVSVPVN KLVVDTL SPTSWQASTFFVRNGSNPEQDPLRNLSGQAVTRVVGGMSTHWTCATPRFDREQRPLLVKDDP DADDAIWDQLYTKAESYFKTGTDQFN ESIRHNLVLNKLAEEYKGQRTFQQI PLAATRRNPTFVE WSSANTVFDLQNRPNI DAPEERFNLFPAVACERVMRNASNTAIESLHIRDLISGDRFAIQADVYVL TAGAVH NTQLLVNSGFGKLGRPDPANPPELLPFLGSYITEQSLVFCQTVMSTELIDSVKSDMTII GN PGELGYSVSYMPGASTN KH PDWWN EKVQNH MMQHQEDPLPIPFEDPEPQVTTLFQPSHP WHTQI HRDAFSYGAVQQSIDSRLIVDWRFFGRTEPKEEN KLWFSDKITDAYNMPQPTFDFRFPA GRTSQEAEDMMTDMCVMSAKIGGFLPGSLPQFMEPGLVLHLGGTHRMGFDEQEDNCCVDTD SRVFGFNN LFLGGCGN IPTAYGANPTLTAMSLAIKSCEYI KKNFTPSPFTPAQ

[0232] SEQ I D NO:9 atggcatctgcacctattggtagcgccattcctcgcaacaactgggccgtcacttgcgacagtgcacagtcgggaaatg aatgcaacaaggccattgatggcaacaaggataccttttggcacacattctatggcgccaacggggatccaaagccccctcac acatacacgattgacatgaagacaactcagaacgtcaacggcttgtctgtgctgcctcgacaggatggtaaccaaaacggctgg atcggtcgccatgaggtttatctaagctcagatggcacaaactggggcagccctgttgcgtcaggtagttggttcgccgactctac tacaaaatactccaactttgaaactcgccctgctcgctatgttcgtcttgtcgctatcactgaagcgaatggccagccctggacta gcattgcagagatcaacgtcttccaagctagttcttacacagccccccagcctggtcttggacgctggggtccgactattgactta ccgattgttcctgcggctgcagcaattgaaccgacatcgggacgagtccttatgtggtcttcatatcgcaatgatgcatttgaagg atcccctggtggtatcactttgacgtcttcctgggatccatccactggtattgtttccgaccgcactgtgacagtcaccaagcatgat atgttctgccctggtatctccatggatggtaacggtcagatcgtagtcacaggtggcaacgatgccaagaagaccagtttgtatga ttcatctagcgatagctggatcccgggacctgacatgcaagtggctcgtgggtatcagtcatcagctaccatgtcagacggtcgtg tttttaccattggaggctccttcagcggtggcgtatttgagaagaatggcgaagtctatagcccatcttcaaagacatggacgtcc ctacccaatgccaaggtcaacccaatgttgacggctgacaagcaaggattgcttttttcagacaaccacgcgtggctctttggatg gaagaagggttcggtgttccaagcgggacctagcacagccatgaactggtactataccagtggaagtggtgatgtgaagtcagc cggaaaacgccagtctaaccgtggtgtagcccctgatgccatgtgcggaaacgctgtcatgtacgacgccgttaaaggaaagat cctgacctttggcggctccccagattatacagactctgacgccacaaccaacgcccacatcatcaccctcggtgaacccggaac atctcccaacactgtctttgctagcaatgggttgtactttgcccgaacgtttcacacctctgttgttcttccagacggaagcacgttta ttacaggaggccaacgacgtggaattccgttcgaggattcaaccccggtatttacacctgagatctacgtccctgaacaagaca ctttctacaagcagaaccccaactccattgttcgcgcctaccatagcatttcccttttgttacctgatggcagggtatttaacggtgg tggtggtctttgtggcgattgtaccacgaatcatttcgacgcgcaaatctttacgccaaactatctttacgatagcaacggcaatct cgcgacacgtcccaagattaccagaacctctacacagagcgtcaaggtcggtggcagaattacaatctcgacggattcttcgat tagcaaggcgtcgttgattcgctatggtacagcgacacacacggttaatactgaccagcgccgcattcccctgactctgacaaac aatggaggaaatagctattctttccaagttcctagcgactctggtgttgctttgcctggctactggatgttgttcgtgatgaactcggc cggtgttcctagtgtggcttcgacgattcgcgttactcag

[0233] SEQ ID NO:10

[0234] MASAPIGSAISRNNWAVTCDSAQSGNECN KAIDGNKDTFWHTFYGANGDPKPPHTYTID MKTTQNVNGLSMLPRQDGNQNGWIGRHEVYLSSDGTNWGSPVASGSWFADSTTKYSNFETR PARYVRLVAITEANGQPWTSIAEINVFQASSYTAPQPGLGRWGPTI DLPIVPAAAAI EPTSGRVLM WSSYRNDAFGGSPGGITLTSSWDPSTGIVSDRTVTVTKHDMFCPGISMDGNGQIVVTGGNDAK KTSLYDSSSDSWI PGPDMQVARGYQSSATMSDGRVFTIGGSWSGGVFEKNGEVYSPSSKTWTS LPNAKVNPMLTADKQGLYRSDN HAWLFGWKKGSVFQAGPSTAMNWYYTSGSGDVKSAGKRQ SNRGVAPDAMCGNAVMYDAVKGKILTFGGSPDYQDSDATTNAHIITLGEPGTSPNTVFASNGLY FARTFHTSVVLPDGSTFITGGQRRGIPFEDSTPVFTPEIYVPEQDTFYKQNPNSIVRVYHSISLLLP DGRVFNGGGGLCGDCTTNH FDAQIFTPNYLYNSNGN LATRPKITRTSTQSVKVGGRITISTDSSI SKASLI RYGTATHTVNTDQRRIPLTLTNNGGNSYSFQVPSDSGVALPGYWMLFVMNSAGVPSV ASTI RVTQ

[0235] SEQ ID NO:11: atgggattgaccgttcaaaagatcaactgggagcaggtaaaagagtgggatcgcaaatacctgatgcgtacacgcagc acccagaacgaatatcagcctgtcccgatcgagtccaccgaaggtgactacctgatcatgccaggtggtacccgtctgctggatt tcttcaatcagctgtattgcgtgaatattgggcagaagaaccagaaagtcaatgcggctattaaggaagcgttggatcgttatggc tttgtttgggatgcctatgctaccgattataaagcaaaagcggccaaaatcattatcgaagatatccttggcgatgaggattggcc gggaaaagtgcgctttgtctcaactggcagtgaagcggtagaaacggcgctgaacattgcgcgcctctacaccaatcgcccgtt agtggtcacgcgcgagcatgattatcatggctggactggcggtgcagcagccgttacgcgcttgcgttcgtttcagtctggtcttgc gggcgaaaattctgggagctttagtgcgcagattccggggagttcctacaacaatgcagtactgatggcaccaagcccgaacgc tttccaagatagcaacggtaattgcctgaaagacgaaaatggagaactgctgagcgttaaatacacacgtcggatgattgagaa ctatggcccggaacaagtggctgcggtgattacggaagtgccgcagggtgtgggatcaacaatgcctccgtatgaatacattcc gcagattcgcaaaatgaccaaagaactcggcgttctttggattaacgatgaagtgctgactggctttggtcgcacgggtaaatgg ttcggctatcagcactacggtgtccaacccgacatcattacgatgggtaagggcttgtcatcctcgagtctgccagcaggtgccgt agtggtttccaaagaaattgcggcgtttatggacaaacaccgttgggaacagggcagcacctatgcagggcatccagtggcaat ggccgccgtttgtgcgaacttagaagtcatgatggaagagaatctggtggaacaagccaagaatagcggtgagtatattcggag caaactggaactgttgcaagagaaacacaaatctatcgggaacttcgatggttgtggcctgctgtggttagtagaaattgttaatg cggaaaccaaaaccccgtacgtcaaattagatcgcaactttacccgtgggatgaacctgaatcagatccccactcaaattatca tggaaaaggccctcgagaaaggcgtgttaatcggaggcgtgatgcctaacacgatgcgtattggtgcctcgcttaacgtttcacg cggcgatatcgacaaagctatggacgccctggactatgctctggactacctcgagtcgggcgaatggcagcagtcttaa

[0236] SEQ ID NO:12:

[0237] MGLTVQKINWEQVKEWDRKYLMRTRSTQN EYQPVPIESTEGDYLIMPGGTRLLDFFNQL YCVNIGQKNQKVNAAI KEALDRYGFVWDAYATDYKAKAAKIII EDILGDEDWPGKVRFVSTGSEA VETALNIARLYTNRPLVVTREHDYHGWTGGAAAVTRLRSFQSGLAGENSGSFSAQI PGSSYN NA VLMAPSPNAFQDSNGNCLKDENGELLSVKYTRRMIENYGPEQVAAVITEVPQGVGSTMPPYEYI PQIRKMTKELGVLWI NDEVLTGFGRTGKWFGYQHYGVQPDIITMGKGLSSSSLPAGAVVVSKEIA AFMDKHRWEQGSTYAGHPVAMAAVCAN LEVMMEENLVEQAKNSGEYI RSKLELLQEKHKSIG NFDGCGLLWLVEIVNAETKTPYVKLDRN FTRGMN LNQIPTQIIM EKALEKGVLIGGVMPNTMRI GASLNVSRGDI DKAM DALDYALDYLESGEWQQS

Claims

Claims1. A process for the preparation of L-glufosinate, the process comprising the following steps: a) reacting a compound according to formula (I)wherein wherein R1is hydrogen, (C1-C12)-alkyl, (C1-C12)-haloalkyl, (C6-C10)-aryl, (C6-C10)-haloaryl, (C7-C10) -a ra I kyl , (C7-C10)-haloaralkyl, (C4-C10)-cycloalkyl, or (C4-C10)-halocycloalkyl, with a compound according to formula (II)(ID wherein R2and R3are independently from each other (C1-C8)-acyloxy, (Cj-C8)- alkoxy or hydroxy, or R2and R3form together an epoxide group or an ethylene carbonate group, and optional subsequent acidic treatment to form a diol according to formula (I II)b) Oxidizing the diol according to formula (I II) to form 2-oxo-4- (hydroxy(methyl)phosphinoyl)butyric acid (PPO); and c) aminating the PPO to L-glufosinate.

2. The process according to claim 1, wherein step c) is carried out as step cl) in the presence of a transaminase (TA) enzyme using an amine group from one or more amine donors, or as step c2) in the presence of an L-amino acid dehydrogenase (LAAD) enzyme using an ammonia source.

3. The process according to claims 1 or 2, wherein in step cl) the amine donor is selected from the group consisting of glutamate, L-glutamate, alanine, secbutylamine, phenylethylamine, glycine, lysine, valine, serine, glutamine,isopropylamine, ethanolamine, 2-aminobutyric acid, diaminoproprionic acid, or any secondary amine or amino acid, preferably the amine donor is isopropylamine.

4. The process of claim 1, wherein in step cl) the TA enzyme , is an enzyme encoded by SEQ ID NO: 12.

5. The process according to any of the preceding claims 1 to 4, wherein the steps b) and c) are carried out in a single container.

6. The process according to any of the preceding claims 1 to 5, wherein step a) is carried out with aid of a radical-forming radiation source or in the presence of one or more radical-forming substance.

7. The process according to claim 6, wherein the one or more radical-forming substance comprises a compound of formula (VI)whereinR6is methyl, ethyl, 2,2-dimethyl propyl or phenyl,R7independently at each occurrence is (C1-C10)-alkyl andR8is hydrogen or (C1-C10)-alkyL8. The process according to any of the preceding claims 1 to 7, wherein step b) is carried out as step bl) in the presence of an enzyme or as step b2) in the presence of a chemical catalyst.

9. The process according to claim 8, wherein in step b2) the chemical catalyst is a platinum-group metal catalyst, wherein the oxidizing step is further carried out, preferably in an aqueous solution of an alkali, in the presence of a gas comprising molecular oxygen and a compound comprising lead and / or bismuth.

10. The process according to claim 9, wherein in step b2) the compound comprising lead and / or bismuth comprises one or more compounds selected from the group consisting of lead in elemental form, bismuth in elemental form, lead in oxide form, bismuth in oxide form, lead in hydracid salt form, bismuth in hydracid salt form, lead in form of a salt of an inorganic oxyacid, bismuth in form of a salt of an inorganic oxyacid, lead in form of a salt of a transition-metal-comprising oxyacid, bismuth in form of a salt of a transition-metal-comprising oxyacid, lead in form of a salt of an organic aliphatic oraromatic acid, and bismuth in form of a salt of an organic aliphatic or aromatic acid, preferably is selected from lead in elemental form and bismuth in elemental form, most preferably is bismuth in elemental form.

11. The process according to any of the preceding claims 9 or 10, wherein in step b2) the platinum-group metal catalyst is selected from platinum and palladium.

12. The process according to claim 8, wherein in step bl) the enzyme is an Oxidoreductase ECI enzyme, preferably the Oxidoreductase ECI enzyme is selected from the group consisting of EC1.1, EC1.2 or EC1.10, more preferably EC1.1.1, EC1.1.3, EC1.2.1, EC1.2.3.

13. A composition comprising 2-oxo-4-(hydroxy(methyl)phosphinoyl)butyric acid (PPO) according to formula (IV)(IV), and aditionally a diol according to formula (III)and L-glufosinate14. A composition according to claim 13, the composition further comprising a hydroxymethyl ketone according to formula (V):(V).

15. A method of selectively controlling weeds in an area comprising a crop of planted seeds or crops that are resistant to glufosinate using a composition according to any of the preceding claims 13 or 14.

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