A cyclopropane monophosphine ligand-cobalt complex, preparation method and application

Abstract

The present invention belongs to the field of catalysts and relates to a cyclopropane monophosphine ligand-cobalt complex, a preparation method and an application thereof. The cyclopropane monophosphine ligand-cobalt complex has the following structural formula: wherein: R 1 、R 2 is phenyl or substituted phenyl, R 3 、R 4 is phenyl, substituted phenyl or C1-C8 alkyl, R 1 、R 2 、R 3 、R 4 The catalysts of the present invention can be the same or different. They are simple to synthesize, easily scalable, and have excellent stability. The catalysts are capable of highly active hydroformylation of a variety of simple olefins and highly regioselective hydroformylation of vinyl ethers, thereby providing a hydroformylation process with mild conditions, simple operation, and high chemoselectivity.

Description

Technical Field

[0001] The present invention belongs to the field of catalysts, and in particular relates to a cyclopropane monophosphine ligand-cobalt complex, a preparation method and an application thereof. Background Art

[0002] The hydroformylation of olefins is an important method for synthesizing aldehydes. This process links petrochemical products (olefins) with coal chemicals (synthesis gas), utilizes inexpensive raw materials, and boasts 100% atom economy. The resulting linear aldehydes are used in plasticizers, detergents, and surfactants on a million-ton scale, while branched-chain aldehydes are primarily used as intermediates in pharmaceuticals and fine chemicals. As the most successful industrial application of homogeneous catalysis to date, hydroformylation currently produces over 12 million tons of aldehydes annually.

[0003] Cobalt catalysts and rhodium catalysts are the two most commonly used catalytic systems in the hydroformylation industry. However, the scarcity and high price of rhodium resources have prompted people to refocus on cobalt catalysts. However, existing cobalt catalytic systems such as (1) Hanf, S. et al. Catalysts. 2020, 10, 510. (2) Kumar, R. et al. J. Organomet. Chem. 2022, 960, 122231 often have harsh reaction conditions (reaction temperature is usually 140-180 ° C, reaction pressure is usually 50-350 bar), low reaction activity and selectivity (turnover number TON is usually <2000, the ratio of direct-chain product to branched product l / b is usually <10), and there is also the problem of limited substrate applicability, which restricts the application of cobalt-catalyzed olefin hydroformylation.

[0004] The purpose of the present invention is to develop a novel cobalt catalyst to achieve efficient hydroformylation of various olefin substrates, thereby providing technical support for the high-value utilization of olefins. Summary of the Invention

[0005] The present invention aims to overcome the shortcomings of the prior art by providing a cyclopropane monophosphine ligand-cobalt complex, its preparation method, and its application. This complex efficiently catalyzes the hydroformylation of various simple alkyl olefins, primarily yielding linear products with turnover numbers up to 3000. It can also catalyze the hydroformylation of vinyl ethers to yield single branched products. The reaction conditions are mild, the operation is simple, and the chemical selectivity is high.

[0006] The first aspect of the present invention is to provide a cyclopropane monophosphine ligand-cobalt complex (I), which has the following structural formula:

[0007]

[0008] in:

[0009] R1 、R 2 is phenyl, substituted phenyl, R 3 、R 4 is phenyl, substituted phenyl, C1-C8 alkyl, R 1 、R 2 、R 3 、R 4 It can be the same or different;

[0010] Furthermore, the substituents in the substituted phenyl group are one or a combination of two or more of C1-C8 alkyl, C1-C8 alkoxy, C2-C8 acyloxy, hydroxy, halogen, amino, (C1-C8 acyl)amino, di(C1-C8 alkyl)amino, C1-C8 acyl, C2-C8 ester, and haloalkyl; the number of substituents is 0-5;

[0011] Furthermore, the C1-C8 alkyl group is methyl, ethyl, n-propyl, isopropyl, cyclopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, sec-pentyl, tert-pentyl, n-hexyl, isohexyl, neohexyl, sec-hexyl, tert-hexyl, n-heptyl, isoheptyl, neoheptyl, sec-heptyl, tert-heptyl, n-octyl, isooctyl, neooctyl, sec-octyl or tert-octyl;

[0012] Furthermore, the C1-C8 acyl group is formyl, acetyl, propionyl, n-butyryl, isobutyryl, n-valeryl, isovaleryl, secondary valeryl, pivaloyl, n-hexanoyl, isohexanoyl, neohexanoyl, secondary hexanoyl, n-heptanoyl, isoheptanoyl, neoheptanoyl, secondary heptanoyl, n-octanoyl, isooctanoyl, neooctanoyl, secondary octanoyl, 1-cyclopropylformyl, 1-cyclobutylformyl, 1-cyclopentylformyl, 1-cyclohexylformyl, 1-cycloheptylformyl;

[0013] Furthermore, the C2-C8 acyloxy group is acetoxy, propionyloxy, n-butyryloxy, isobutyryloxy, n-valeryloxy, isovaleryloxy, secondary valeryloxy, pivaloyloxy, n-hexanoyloxy, isohexanoyloxy, neohexanoyloxy, secondary hexanoyloxy, n-heptanoyloxy, isoheptanoyloxy, neoheptanoyloxy, secondary heptanoyloxy, n-octanoyloxy, isooctanoyloxy, neooctanoyloxy, secondary octanoyloxy, 1-cyclopropylcarbonyloxy, 1-cyclobutylcarbonyloxy, 1-cyclopentylcarbonyloxy, 1-cyclohexylcarbonyloxy, 1-cycloheptylcarbonyloxy;

[0014] Further, the C2-C8 ester group is methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, isobutoxycarbonyl, n-pentyloxycarbonyl, isopentyloxycarbonyl, neopentyloxycarbonyl, secondary pentyloxycarbonyl, tert-pentyloxycarbonyl, cyclopentyloxycarbonyl, n-hexyloxycarbonyl, isohexyloxycarbonyl, neohexyloxycarbonyl, secondary hexyloxycarbonyl, tert-hexyloxycarbonyl, cyclohexyloxycarbonyl, n-heptyloxycarbonyl, isoheptyloxycarbonyl, neoheptyloxycarbonyl, secondary heptyloxycarbonyl, tert-heptyloxycarbonyl, or cycloheptyloxycarbonyl;

[0015] Furthermore, the haloalkyl group is a haloalkyl group containing fluorine, chlorine, bromine or iodine.

[0016] Furthermore, the cyclopropane monophosphine ligand-cobalt complex (I) is preferably:

[0017]

[0018] Furthermore, the cyclopropane monophosphine ligand-cobalt complex (I) can be a monomer, a dimer or a solvated complex.

[0019] The second aspect of the present invention is to provide a method for preparing the cyclopropane monophosphine ligand-cobalt complex (I), comprising the following steps:

[0020] (1) Preparation of cyclopropane monophosphine ligand (II). The specific method is to start from trans-1,2-diarylethene, use NaOH as base and TEBAC (benzyltriethylammonium chloride) as phase transfer catalyst, and carry out cyclopropanation with bromoform to prepare gem-dibromocyclopropane (III); then use LiBr as additive, and carry out bromine-lithium exchange with n-butyllithium at -100℃ to obtain monobromocyclopropane (IV); finally, carry out bromine-lithium exchange again and react with PR 3 R 4 Cl reaction, borane protection to obtain cyclopropane skeleton monophosphine ligand borane adduct, using DABCO (1,4-diazabicyclo [2.2.2] octane) deboranization to obtain cyclopropane skeleton monophosphine ligand (II), used for subsequent complexation reaction.

[0021]

[0022] (2) Preparation of cyclopropane monophosphine ligand-cobalt complex (I). In tetrahydrofuran, at 25-150° C., cyclopropane monophosphine ligand and corresponding cobalt salt (1 equivalent) are complexed for 1-48 hours to prepare cyclopropane monophosphine ligand-cobalt complex (I), the reaction formula of which is:

[0023]

[0024] The third aspect of the present invention provides the use of the cyclopropane monophosphine ligand-cobalt complex (I) as a catalyst for the hydroformylation of olefins, the reaction equation of which is:

[0025]

[0026] The cyclopropane monophosphine ligand (II) can also be complexed with a cobalt precursor in situ to prepare a cyclopropane monophosphine ligand-cobalt complex (I), which can be used in the hydroformylation of olefins. The reaction equation is:

[0027]

[0028] Among them, R 5 It is an alkyl group, a substituted alkyl group, or a phenyl group.

[0029] R 5 The alkyl group refers to a straight-chain or branched-chain alkyl group having 1 to 20 carbon atoms, for example, methyl, ethyl, n-propyl, n-butyl, isobutyl, tert-butyl, n-hexyl, octyl, decyl, dodecyl, hexadecyl, etc., preferably a straight-chain alkyl group having 1 to 16 carbon atoms, particularly preferably a straight-chain alkyl group having 4 to 16 carbon atoms, and most preferably n-butyl, n-hexyl, n-decyl, and n-hexadecyl.

[0030] R 5 The substituted alkyl group refers to a terminally substituted straight-chain or branched alkyl group having 1 to 20 carbon atoms, for example, benzyl, phenethyl, phenylpropyl, allyl, propargyl, hydroxymethyl, aminomethyl, chloromethyl, etc., preferably a straight-chain alkyl group having 1 to 16 carbon atoms with a terminal phenyl group, and particularly preferably a straight-chain alkyl group having 4 to 6 carbon atoms with a terminal phenyl group.

[0031] The in-situ complexation method is as follows: in a solvent required for the hydroformylation reaction, a cyclopropane monophosphine ligand and a corresponding cobalt salt (1 equivalent) are stirred at room temperature under an argon atmosphere for ten minutes.

[0032] In the application of the cyclopropane monophosphine ligand-cobalt complex (I), reactants, catalyst, and degassed solvent are sequentially added to a hydrogenation inner tube under an argon atmosphere, and then heated and stirred under a synthesis gas (hydrogen and carbon monoxide mixture) atmosphere until the reaction is completed.

[0033] Furthermore, the solvent used is one or more organic solvents selected from tetrahydrofuran, anisole, ethylene glycol dimethyl ether, methanol, ethanol, isopropanol, and toluene; the catalyst dosage is 0.1-1 mol%; the synthesis gas ratio and pressure are H2 / CO=1:1-3:1, 40atm-80atm; the substrate concentration is 0.001-10.0M; the reaction temperature is 100-150°C; and the reaction is carried out for 1-72 hours.

[0034] A fourth aspect of the present invention provides the use of the cyclopropane monophosphine ligand-cobalt complex (I) as a catalyst for the highly regioselective hydroformylation of vinyl ethers, wherein the reaction equation is:

[0035]

[0036] Among them, R 6 It is a substituted alkyl group, a phenyl group, or a substituted phenyl group.

[0037] R 6 The substituted alkyl group refers to a terminally substituted straight-chain or branched alkyl group having 1 to 20 carbon atoms, for example, benzyl, phenethyl, phenylpropyl, allyl, propargyl, hydroxymethyl, aminomethyl, chloromethyl, etc., preferably a straight-chain alkyl group having 1 to 16 carbon atoms with a terminal phenyl group, and particularly preferably a straight-chain alkyl group having 4 to 6 carbon atoms with a terminal phenyl group.

[0038] R 6 The substituted phenyl group refers to a phenyl group substituted with one or more halogens or alkyl groups, for example: o-tolyl, p-tolyl, m-tolyl, mesityl, mesityl, unityl, o-chlorophenyl, o-bromophenyl, m-fluorophenyl, etc., preferably a phenyl group substituted with one or more chlorine atoms or methyl groups, and particularly preferably a phenyl group substituted with one chlorine atom or methyl group.

[0039] Cyclopropane monophosphine ligand-cobalt complex (I) was prepared by in situ complexation of cyclopropane monophosphine ligand with cobalt precursor for high regioselective hydroformylation of vinyl ether.

[0040] Advantages and beneficial effects of the present invention:

[0041] The present invention complexes a synthesized cyclopropane monophosphine ligand with a cobalt salt to prepare a novel cyclopropane monophosphine ligand-cobalt complex. This catalyst is simple to synthesize, easily scalable, and exhibits excellent stability. The novel catalyst is capable of highly active hydroformylation of a variety of simple olefins and highly regioselective hydroformylation of vinyl ethers, providing a hydroformylation condition characterized by mild conditions, simple operation, and high chemoselectivity. The novel cyclopropane monophosphine ligand-cobalt complex provided by the present invention is one of the most efficient cobalt-catalyzed hydroformylation catalysts currently available and has promising application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 is the H NMR spectrum of cyclopropane monophosphine ligand II-f ( 1 H NMR) spectra;

[0043] Figure 2 is the C NMR spectrum of cyclopropane monophosphine ligand II-f ( 13 C NMR) spectra;

[0044] Figure 3 is the NMR phosphine spectrum of cyclopropane monophosphine ligand II-f ( 31 P NMR) spectra;

[0045] Figure 4 The H NMR spectrum of cyclopropane monophosphine ligand-cobalt complex If ( 1 H NMR) spectra;

[0046] Figure 5 The C NMR spectrum of cyclopropane monophosphine ligand-cobalt complex If ( 13 C NMR) spectra;

[0047] Figure 6 is the NMR phosphine spectrum of cyclopropane monophosphine ligand-cobalt complex If ( 31 P NMR) diagram. DETAILED DESCRIPTION

[0048] The following embodiments will help to further understand the present invention, but it should not be understood that the scope of the above subject matter of the present invention is limited to the following embodiments. All technologies implemented based on the above content of the present invention belong to the scope of the present invention.

[0049] General Notes:

[0050] The abbreviations used in the following examples have the following meanings:

[0051] Me is methyl, Et is ethyl, t Bu is tert-butyl, n Bu is n-butyl, Ph is phenyl, Tol. is toluene, THF is tetrahydrofuran, Et2O is diethyl ether, anisole is anisole, t-glyme is triethylene glycol dimethyl ether, 1,4-dioxane is 1,4-dioxane, DME is ethylene glycol dimethyl ether, DMF is N,N-dimethylformamide, PhCl is chlorobenzene, 2-Me-THF is 2-methyltetrahydrofuran, PE is petroleum ether, EA is ethyl acetate, Ar is argon, CDCl3 is deuterated chloroform, and TMS is a trimethylsilyl substituent.

[0052] eq. is equivalent, rt stands for room temperature, S / C is the molar ratio of substrate to catalyst, ND stands for not detected, TLC is thin layer chromatography, NMR is nuclear magnetic resonance, HRMS is high resolution mass spectrometry, GC is gas chromatography, TON is turnover number = molar ratio of product aldehyde / molar ratio of catalyst, CS is chemoselectivity = product aldehyde yield / conversion, l / b is isomeric ratio = linear aldehyde yield / branched aldehyde yield.

[0053] The solvents used were purified and dried by standard procedures before use; the reagents used were commercially available or synthesized according to existing literature methods and purified before use.

[0054] Example 1: Synthesis of cyclopropane monophosphine ligand (II)

[0055] Synthesis of 2,3-diphenylcyclopropyldi-tert-butylphosphine borane adduct II-a:

[0056]

[0057] Under air, trans-1,2-diphenylethylene (1.8 g, 10 mmol) and TEBAC (benzyltriethylammonium chloride, 0.46 g, 2 mmol) were weighed into a 250 mL three-necked flask equipped with an electromagnetic stirrer, and 20 mL of bromoform was added. 20 mL of saturated aqueous NaOH solution was added dropwise under an ice bath at 0°C. After completion, stirring was continued at 0°C for 20 minutes, and then returned to room temperature and stirred. After 5 hours, water was added to quench the reaction, the liquids were separated, and the aqueous phase was extracted with dichloromethane (100 mL × 3). The organic phase was washed with water and dried over anhydrous Na2SO4. Filtered, the filtrate was concentrated by rotary evaporation, and the crude product was separated by silica gel column chromatography (eluent: petroleum ether) to obtain product III-a (3.28 g, yield 92%).

[0058] Under argon protection, LiBr (0.883 g, 10.1 mmol), 1 mL of ether and 1 mL of tetrahydrofuran were added to a 100 mL dry Schlenk tube equipped with an electromagnetic stirrer. The system was cooled to -100 °C in an ice-water bath and slowly added dropwise n BuLi n-hexane solution (4.0 mL, 2.5 M, 10.1 mmol). The system was transferred to a liquid nitrogen ethanol (-100 ° C) system, and the tetrahydrofuran solution of III-a was added dropwise using a syringe pump. The addition was completed in about 1 hour. After stirring at low temperature for 1 hour, the reaction system was quenched with ethanol, water was added, and petroleum ether was extracted three times (10 mL × 3), and dried over anhydrous MgSO4. Filtered, the filtrate was concentrated by rotary evaporation, and the crude product was separated by silica gel column chromatography (eluent: petroleum ether) to obtain product IV-a (1.81 g, yield 72%).

[0059] Reactant IV-a (1.81 g, 6.6 mmol) was weighed into a 100 mL Schlenk bottle equipped with electromagnetic stirring, dissolved in anhydrous tetrahydrofuran under argon atmosphere, and added dropwise at -100 °C. n BuLi n-hexane solution (3.1 mL, 2.5 M, 7.9 mmol) was stirred at low temperature for 1 hour. tBu2Cl (2.38 g, 2 mmol), the reaction system was naturally warmed to room temperature and stirred for 4 hours. After the reaction was completed by TLC monitoring, the temperature was controlled in an ice-water bath (0 ° C), and borane tetrahydrofuran solution (26 mL, 1.0 M, 4 mmol) was added to the system, and the system was restored to room temperature and stirred for 12 hours. The temperature was controlled in an ice-water bath, and water was added dropwise to quench the reaction system. The reaction was extracted three times with 10 mL of ethyl acetate, the organic phases were combined, and dried over anhydrous MgSO4. Drying with anhydrous MgSO4. Filter, concentrate the filtrate by rotary evaporation, and the crude product was separated by silica gel column chromatography (eluent: petroleum ether, petroleum ether / ethyl acetate = 100: 1) to obtain the target product II-a (1.51 g, yield 65%)

[0060] In a 25 mL Schlenk flask, II-a (1.51 g, 4.3 mmol) and DABCO (1.44 g, 6 mmol) were weighed. The atmosphere was replaced with argon, and anhydrous THF (20 mL) was added. The mixture was stirred at 50°C for 8 hours. Purification by silica gel column chromatography under anhydrous and oxygen-free conditions afforded the desired product Ia as a colorless oil (1.37 g, 94% yield).

[0061] 1 HNMR(400MHz, CDCl3)δ7.33–7.24(m,6H),7.23–7.14(m,4H),2.63–2.55(m,1H),

[0062] 2.55–2.47(m,1H),1.79–1.71(m,1H),1.16(d,J=10.9Hz,9H),0.95(d,J=10.8

[0063] Hz,9H).

[0064] 13 CNMR(101MHz, CDCl3)δ141.93,139.73,139.70,128.64,127.68,126.06,125.87,125.71,33.84,33.81,32.30,32.2 8,32.11,32.09,31.97,31.87,31.79,30.45,30.33,30.22,30.00,29.92,29.87,29.79,26.88,26.80,26.63,26.53.

[0065] 31 P NMR (162 MHz, CDCl3) δ 12.88.

[0066] The synthesis method of the following compounds is the same as that of Example 1, except that the phenyl group is replaced by a substituted phenyl group.

[0067]

[0068] Colorless oily compound, total yield 43%.

[0069] 1 HNMR(400MHz, CDCl3)δ7.41–7.35(m,2H),7.33–7.14(m,18H),2.97–2.82(m,2H),

[0070] 2.12–2.03 (m, 1H).

[0071] 13 CNMR(101MHz,CDCl3)δ(101MHz,CDCl3)δ141.29,139.47,139.37,139.14,139.04,138.25,138.19,133.09,132.90,132.71,132.53,129. 22,129.19,128.67,128.57,128.50,128.44,128.36,128.29,128.06 ,126.65,126.59,126.37,32.41,32.35,29.92,29.84,29.48,29.35.

[0072] 31 P NMR (162MHz,CDCl3)δ-16.18.

[0073]

[0074] Colorless oily compound, total yield 40%.

[0075] 1 HNMR(400MHz, CDCl3)δ7.26–7.15(m,6H),7.14–7.04(m,4H),2.52–2.44(m,2H) ,1.64–1.48(m,8H),1.44–1.29(m,3H),1.28–0.95(m,10H),0.93–0.70(m,2H). 13 CNMR (101MHz, CDCl3) δ142.05,139.33,128.63,127.69,126.00,33.99,32. 30,31.01,30.75,30.17,29.28,27.45,26.59,26.43,22.78,14.30,14.21.

[0076] 31P NMR (162MHz,CDCl3)δ-11.30.

[0077]

[0078] Colorless oily liquid, total yield 40%.

[0079] 1 HNMR(400MHz, CDCl3)δ7.18–7.13(m,2H),7.09–7.02(m,6H),2.54–2.46(m,1H),

[0080] 2.43–2.38(m,1H),2.29(s,3H),2.27(s,3H),1.68–1.63(m,1H),1.13(d,J=10.8

[0081] Hz,9H),0.93(d,J=10.8Hz,9H).

[0082] 13 CNMR(101MHz, CDCl3)δ138.97,136.68,136.65,135.43,135.18,129.44,129.38,129.31,129.26,128.46,128.35,125.60,33.38 ,33.32,32.29,32.27,32.11,32.09,31.40,31.30,31.20,30.51,30.35,30.20,30.07,29.94,29.81,26.49,26.26,26.02,21.13.

[0083] 31 P NMR (162 MHz, CDCl3) δ 12.97.

[0084]

[0085] Colorless oily compound, total yield 38%.

[0086] 1 HNMR(400MHz, CDCl3)δ7.25–7.18(m,4H),7.16–7.10(m,2H),7.07–7.02(m,2H),

[0087] 2.48(dt,J=9.1,6.3Hz,1H),2.40–2.33(m,1H),1.68–1.62(m,1H),1.26–1.19(m,

[0088] 18H), 1.10 (d, J=10.8Hz, 9H), 0.88 (d, J=10.8Hz, 9H).

[0089] 13 CNMR (101MHz, CDCl3) δ148.72,148.51,138.91,136.72,136.69,128.22,125.58,125.38,124.67,124.42,34.49,34.46,33. 35,32.30,32.28,32.11,31.61,31.42,31.26,30.57,30.42,30.27,30.03,29.91,29.79,27.13,26.01,22.79,14.32,14.24.

[0090] 31 PNMR (162MHz,CDCl3)δ13.01.

[0091]

[0092] Colorless oily compound, total yield 36%.

[0093] 1 HNMR(400MHz, CDCl3)δ7.25–7.18(m,4H),7.09–7.05(m,2H),3.31–3.21(m,1H),

[0094] 2.60–2.54(m,1H),2.48–2.42(m,1H),1.33(s,63H),1.17(d,J=11.0Hz,9H),0.89

[0095] (d, J = 10.5 Hz, 9 H).

[0096] 13 CNMR (101MHz, CDCl3) δ150.69,149.51,141.08,139.23,123.50,123.32,120.66,120.61,120.51,119.87,119.86,119. 40,119.23,35.03,34.93,34.02,33.04,32.28,32.07,31.82,31.63,30.64,30.48,30.34,30.11,29.99,29.87,25.05.

[0097] 31 P NMR (162 MHz, CDCl3) δ 14.43.

[0098]

[0099] 1 HNMR(400MHz, CDCl3)δ7.56(d,J=7.7Hz,1H),7.25–7.06(m,6H),6.98–6.93(m,1H),

[0100] 3.49(dt,J=12.2,7.2Hz,1H),2.53(m,4H),2.41(s,3H),1.93(ddd,J=9.5,6.9,4.8

[0101] Hz,1H),1.23(d,J=12.2Hz,9H),1.08(d,J=12.8Hz,9H).

[0102] 13 CNMR(101MHz, CDCl3)δ139.07,137.47,137.35,133.97,133.95,130.50,129.78,129.75,127.09,126.46,126.20,1 25.52,122.13,34.20,33.92,33.68,33.63,32.41,32.13,28.23,28.21,28.04,23.85,20.50,20.46,20.04,19.67.

[0103] 31 PNMR (162MHz,CDCl3)δ13.26

[0104]

[0105] White solid, yield 71%, melting point: 186-188°C.

[0106] 1 HNMR(400MHz, CDCl3)δ7.43–7.19(m,16H),7.11(dd,J=5.3,3.3Hz,1H),6.81(d,J=

[0107] 7.7Hz,1H),3.35(dt,J=11.9,7.3Hz,1H),2.98(dt,J=9.6,7.5Hz,1H),1.55(ddd,J

[0108] =9.6,7.2,5.3Hz,1H),1.04(d,J=12.2Hz,9H),0.94(d,J=12.8Hz,9H).

[0109] 13 CNMR(101MHz, CDCl3)δ143.34,143.26,141.90,140.69,138.10,132.61,132.58,130.12,129.97,129.95,129.84,128.37,128.23,127.91,1 27.49,126.94,126.85,126.71,125.87,122.04,33.96,33.68,33.39, 33.34,32.40,32.12,28.20,28.18,27.90,25.06,21.26,21.11,20.90.

[0110] 31 P NMR (162 MHz, CDCl3) δ 11.32

[0111] Example 2: Synthesis of Cyclopropane Monophosphine Ligand Cobalt Complex (I)

[0112] Synthesis of 2,3-bis(3,5-di-tert-butylphenyl)-1,1-dibromocyclopropane-cobalt complex If:

[0113]

[0114] In a glove box, cyclopropane monophosphine ligand II-f (112.6 mg, 0.2 mmol) and Co2(CO)8 (38 mg, 0.11 mmol) were added to a 10 mL dry Schlenk tube. The system was placed under an argon atmosphere, and 2 mL of ultra-dry tetrahydrofuran was added. The reaction was allowed to proceed at 60°C for 4 h. After the reaction was complete, the system was allowed to return to room temperature, 5 mL of ultra-dry n-pentane was added, and the mixture was allowed to stand for 24 h. The residue was filtered, washed three times with 5 mL of ultra-dry n-pentane each time, and dried to obtain the cyclopropane monophosphine ligand cobalt complex (If) as a dark brown solid (120 mg, yield: 71%); melting point: >250°C (decomposition).

[0115] 1 H NMR(400MHz,CDCl3) δ7.08(m,2H),6.79(m,4H),3.14(bs,1H),2.57(bs,1H),1.97(bs,1H),1.51(s,9H),1.32(s,9H),1.14(s,36H).

[0116] 13C NMR (101MHz, CDCl3) δ203.52,202.54,201.12,131.88,131.59,130.20,129.81,129.17,1 29.13,128.02,127.74,127.29,35.27,33.59,31.67,29.71,28.78,28.11,27.54,26.94.

[0117] 31P NMR (162MHz, CDCl3) δ108.29.

[0118] HRMS(ESI) calcd for[M-2(CO)],C 80 H 126 Co2O2P2] + :1298.7897,found:1298.7802.

[0119] IR(neat,cm -1 ) 2026.6 1989.3 1863.7

[0120] The synthesis method of the following compounds is the same as that of Example 2, except that the phenyl group is replaced by a substituted phenyl group.

[0121]

[0122] Dark brown solid, yield 79%.

[0123] 1 H NMR (400MHz, CDCl3) δ7.41–7.30(m,6H),7.28–7.13(m,4H),2.69–2.58(m,1H),2.57–2.46(m,1H),1.82-1.77(m,1H),1.23(s 9H),1.10(s,9H).

[0124] 13 C NMR (101MHz, CDCl3)δ204.02,202.56,202.31,,140.85,139.21,139.07,129.34,127.35,1 25.96,125.37,125.02,33.85,33.75,32.71,32.69,31.76,31.87,29.34,28.24,26.51

[0125] 31 P NMR (162MHz,CDCl3)δ102.03.

[0126] IR(neat,cm -1 ) 2037.5 1990.7 1843.5

[0127]

[0128] Dark brown solid, yield 85%.

[0129] 1 H NMR (400MHz, CDCl3)δ7.45–7.38(m,2H),7.35–7.12(m,18H),2.98–2.1(m,2H),

[0130] 2.23–2.13 (m, 1H).

[0131] 13 C NMR (101MHz, CDCl3)204.25,203.63,202.98,143.29,141.73,139.87,139.64,139.01,138.78,138.55,134.21,133.60,131.71, 131.53,129.86,129.39,128.87,128.31,128.21,128.03,126.55,126.34,126.21,33.56,33.37,30.23,30.02,29.98,29.56.

[0132] 31 P NMR (162MHz,CDCl3)δ98.32.

[0133] IR(neat,cm -1 ) 2056.3 June 1987 1868.1

[0134]

[0135] Dark brown solid, yield 71%.

[0136] 1 H NMR (400MHz, CDCl3) δ7.31–13(m,10H),2.59–2.43(m,2H),1.69–1.47(m,8H),1.45–81(m,15H).

[0137] 13 C NMR(101MHz, CDCl3)δ204.22,203.03202.95,143.51,139.77,128.69,128.0,127.60,3 9.19,38.61,34.00,31.90,29.36,21.56,20.53,20.30,19.90,17.44,14.45,13.11.

[0138] 31 P NMR (162MHz,CDCl3)δ100.33.

[0139] IR(neat,cm -1 ) 2063.3 1989.3 1867.9

[0140]

[0141] Dark brown solid, yield 70%.

[0142] 1 H NMR (400MHz, CDCl3) δ7.21–7.15(m,2H),7.13–7.01(m,6H),2.53–2.39(m,2H),2.31(s,3H),2.28(s,3H),1.72–1.65(m,1H),1.01–0.91(m,18H).

[0143] 13 C NMR (101MHz, CDCl3)δ202.68,202.31,201.85,139.94,138.34,138.21,134.84,134.81,131.36,130.65,130.61,127.96,127.33 ,127.06,126.38,125.00,34.97,34.79,34.55,34.50,33.27,33.00,29.10,29.08,28.91,24.72,21.37,21.32,20.91,20.54.

[0144] 31 P NMR (162MHz,CDCl3)δ104.23.

[0145] IR(neat,cm -1 ) 2057.6 June 1977 1854.7

[0146]

[0147] Dark brown solid, yield 72%.

[0148] 1 H NMR (400MHz, CDCl3) δ7.25–7.18(m,4H),7.16–7.10(m,2H),7.07–7.02(m,2H),2.48(dt,J=9.1,6.3Hz,1H),2 .40–2.33(m,1H),1.68–1.62(m,1H),1.26–1.19(m,18H),1.10(d,J=10.8Hz,9H),0.88(d,J=10.8Hz,9H).

[0149] 13 C NMR (101MHz, CDCl3)δ203.65,202.34,202.12,144.13,140.83,133.67,130.15,129.94,128.43,127.82,127.62, 127.47,127.25,34.11,33.83,33.54,33.49,32.54,32.27,28.34,28.32,28.05,25.21,21.41,21.26,21.05.

[0150] 31 P NMR (162MHz,CDCl3)δ106.17.

[0151] IR(neat,cm -1 ) 2049.3 1983.1 1849.9

[0152]

[0153] Dark brown solid, yield 69%.

[0154] 1 H NMR (400MHz, CDCl3) δ7.51(m,1H),7.24–6.94(m,7H),3.51–3.40(m,1H),2.61–2.49(m,4H),2.58(s,3H),1.93–1.82(m,1H),1.24–1.08(m,18H).

[0155] 13 C NMR(101MHz, CDCl3) δ202.86,202.61,201.75,138.73,138.42,137.68,135.63,130.22,130.02,128 .68,127.45,127.22,126.43,126.20,125.85,32.29,31.57,30.92,23.52,22.49,22.26,21.86.

[0156] 31 P NMR (162MHz,CDCl3)δ103.61

[0157] IR(neat,cm -1 ) 2075.3 1983.1 1849 9

[0158]

[0159] Dark brown solid, yield 65%.

[0160] 1 H NMR (400MHz, CDCl3) δ7.63–7.31(m,16H),7.25–7.09(m,2H),3.41–3.36(m,1H),3.05(bs,1H),1.61(bs,1H),1.20–0.99(m,18H).

[0161] 13 C NMR (101MHz, CDCl3)δ202.56,202.21,201.64,143.29,143.23,141.88,140.64 ,138.08,132.53,130.08,129.94,129.92,129.90,129.79,128.32,128.17 ,127.84,127.45,126.87,126.81,126.66,125.80,122.0034.53,34.25,33.96,33.91,32.97,32.70,28.76,28.74,28.47,28.46,25.63,21.83,21.47.

[0162] 31 P NMR (162MHz,CDCl3)δ105.95

[0163] IR(neat,cm -1 ) 2081.5 1973 1866.9

[0164] Example 3: Application of Cyclopropane Monophosphine Ligand and Its Cobalt Complex in Cobalt-Catalyzed Hydroformylation

[0165] a)

[0166] Using a pre-prepared catalyst: In an argon-filled glove box, a cyclopropane monophosphine ligand-cobalt complex (If) and 3 mL of tetrahydrofuran were added to a 10 mL hydrogenation inner tube. 1-hexene (86 mg, 1 mmol) was then added. The tube was sealed with parafilm and removed from the container. The mixture was then placed in a sealed hydrogenation kettle. Carbon monoxide was rapidly replaced three times, initially with 13 atm of carbon monoxide, followed by hydrogen to a total pressure of 40 atm. The reaction was stirred in a 120°C oil bath for 3 hours. After the reaction was complete, the system was returned to room temperature, the kettle was vented, and the reaction mixture was filtered through a burette column. Tridecane was added as an internal standard. The conversion number, chemoselectivity (CS = product aldehyde yield / conversion), and regioselectivity (l / b) were calculated using GC.

[0167] b)

[0168] Using an in situ generated catalyst: In an argon-filled glove box, add cyclopropane monophosphine ligand II-f (0.01 mmol), Co(CO) (1.7 mg, 0.005 mmol), and 3 mL of tetrahydrofuran to a 10 mL hydrogenation inner tube. 1-Hexene (86 mg, 1 mmol) is then added. The tube is sealed with parafilm and removed from the container. The mixture is then sealed in a hydrogenation kettle. Carbon monoxide is rapidly replaced three times, initially with 13 atm of carbon monoxide, followed by hydrogen to a total pressure of 40 atm. The reaction is stirred in a 120°C oil bath for 3 hours. After the reaction is complete, the system is returned to room temperature, the kettle is vented, and the reaction mixture is filtered through a burette column. Tridecane is added as an internal standard. Gas chromatography (GC) is used to calculate turnover numbers, chemoselectivity, and regioselectivity.

[0169] Table 1: Experimental results of 1-hexene hydroformylation catalyzed by cyclopropane monophosphine ligand and its cobalt complex

[0170]

[0171]

[0172] a The conversion and selectivity were determined by GC with n-tridecane added as an internal standard. Condition a was a pre-prepared catalyst, while condition b was an in-situ catalyst synthesis during the reaction.

[0173] As shown in Table 1, the ligand significantly affects the yield and chemical selectivity of the hydroformylation reaction. The ligand with higher regioselectivity (l / b = 10:1) given in the literature was used. n Bu3P [Mullineaux, D.; Slaugh.LJ Organomet. Chem. 1968, 13, 469-477.], hardly reacts under these conditions, while a large sterically hindered ligand reported in the literature is used. 292 [Achonduh, G.; Yang, Q.; Alper, H. Tetrahedron, 2015, 71, 1241-1246], the conversion number was only 30, far less than that of cyclopropane monophosphine ligands II-a to II-h. This is enough to demonstrate its superiority in olefin hydroformylation reactions.

[0174] We investigated the effects of substituents on the phosphorus of T-Phos: when the two substituents on the phosphorus atom were changed from phenyl (II-b) to the sterically hindered tert-butyl (II-a), the conversion rate, chemical selectivity, and regioselectivity of the reaction were all improved; the increased steric hindrance of the substituents on the 2,3-position benzene ring of cyclopropane helped to improve the chemical selectivity and conversion number of the reaction (II-d to II-h).

[0175] Example 4: Effects of Different Temperatures and Syngas Conditions on the Hydroformylation of 1-Hexene

[0176]

[0177] Using an in situ generated catalyst: In an argon-filled glove box, add cyclopropane monophosphine ligand II-f (5.6 mg, 0.01 mmol), Co2(CO)8 (1.7 mg, 0.005 mmol), 1-hexene (86 mg, 1 mmol), and 3 mL of t-glyme (tetraethylene glycol dimethyl ether) to a hydrogenation inner tube. Seal the tube with parafilm and remove it from the container. Place it in a hydrogenation kettle, fill it with synthesis gas at different pressures and ratios, and stir it in an oil bath at different temperatures for 12 hours. After the reaction is complete, return the system to room temperature, vent the gas, and open the kettle. Filter the reaction mixture through a burette column. Add n-tridecane as an internal standard. Calculate the turnover number, chemoselectivity, and regioselectivity using GC.

[0178] Table 2: Experimental results of 1-hexene hydroformylation reaction under different temperatures and synthesis gas conditions

[0179]

[0180]

[0181] aConversion and selectivity were determined by GC with n-tridecane added as an internal standard.

[0182] As can be seen from Table 2, the evaluation of synthesis gas pressure shows that the change in pressure has no significant effect on the reaction results. Under the same pressure conditions, when the hydrogen content is greater than the carbon monoxide content, the reaction will have better chemical selectivity and activity. When the hydrogen ratio is too high (CO / H2=1:3, 40atm), the chemical selectivity and activity decrease slightly. Through the investigation of the reaction temperature, we found that when the temperature is lower than 120℃, the reaction is inhibited. When the reaction temperature is between 120-160℃, the reaction can occur well, and the regioselectivity, chemical selectivity and conversion number are all at very high levels.

[0183] Example 5: Effect of different solvents on the hydroformylation of 1-hexene

[0184]

[0185] Using an in situ generated catalyst: In an argon-filled glove box, add cyclopropane monophosphine ligand II-f (5.6 mg, 0.01 mmol), Co2(CO)8 (1.7 mg, 0.005 mmol), 1-hexene (86 mg, 1 mmol), and 3 mL of solvent to a 10 mL hydrogenation inner tube. Seal the tube with parafilm and remove the tube. Place the tube in a hydrogenation autoclave. Rapidly replace the carbon monoxide three times, then fill the autoclave with 13 atm of carbon monoxide each time. Then, fill the autoclave with hydrogen to a total pressure of 40 atm. Stir in a 120°C oil bath for 12 hours. After the reaction is complete, return the system to room temperature, vent the air, and open the autoclave. Filter the reaction mixture through a burette column. Add n-tridecane as an internal standard. GC is used to calculate the turnover number, chemoselectivity, and regioselectivity.

[0186] Table 3: Experimental results of different solvents for the hydroformylation of 1-hexene

[0187]

[0188]

[0189] a The conversion and selectivity were determined by GC with n-tridecane added as an internal standard.

[0190] As can be seen in Table 3, the solvent significantly affects the reaction. Without the use of a solvent, a black insoluble material is obtained after the reaction, and the starting material, product, and by-products are undetectable by GC. The hydroformylation reaction proceeds well in most ether solvents, achieving a regioselectivity of 74:26, a chemoselectivity of 95%, and a conversion of 1:1 in tetrahydrofuran. However, the use of polar protic alcohols significantly increases the number of by-products. The reaction fails when using polar aprotic solvents such as acetonitrile and N,N-dimethylformamide, as well as aromatic solvents such as toluene and chlorobenzene.

[0191] Example 6: Scope of application of alkyl olefin substrates

[0192]

[0193] Using an in situ generated catalyst: In an argon-filled glove box, add cyclopropane monophosphine ligand II-f (5.6 mg, 0.01 mmol), Co2(CO)8 (1.7 mg, 0.005 mmol), substrate (1 mmol), and 3 mL of solvent to a 10 mL hydrogenation inner tube. Seal the tube with parafilm and remove it from the container. Place the tube in a hydrogenation autoclave, rapidly replace carbon monoxide three times, and then fill it with 13 atm of carbon monoxide each time. Then, fill it with hydrogen to a total pressure of 40 atm. Stir the reaction in a 120°C oil bath. After the reaction is complete, return the system to room temperature, vent the air, and open the autoclave. Filter the reaction solution through a burette column. Add n-tridecane as an internal standard. Calculate the turnover number, chemoselectivity, and regioselectivity using GC.

[0194] Table 4: Experimental results of hydroformylation of different alkyl olefin substrates

[0195]

[0196] a The conversion and selectivity were determined by GC with n-tridecane added as an internal standard. b S / C=1000 and the reaction was carried out for 12 hours.

[0197] As can be seen in Table 4, the system has excellent reactivity towards a variety of alkyl olefins, especially some long-chain olefins (Experiments 1-6) and cyclohexene (Experiment 10). Even under the condition of S / C = 1000, the hydroformylation products can be obtained with a chemoselectivity greater than 85%, and the conversion numbers are all above 700, which is at a relatively high level among existing cobalt-catalyzed systems. In a report on similar substrates, the conversion numbers of reactions using this catalyst were less than 100 [Beller, M.A.C.S.Sustainable Chem. Eng. 2021, 9, 5148-5154.]. It is worth mentioning that we can obtain the hydroformylation product of norbornene with a regioselectivity of endo:exo = 80:20, with a conversion number as high as 357, which is not reported in previous cobalt-catalyzed olefin hydroformylation.

[0198] Example 7: Vinyl ether substrate application range

[0199]

[0200] Using an in situ generated catalyst: In an argon-filled glove box, add cyclopropane monophosphine ligand II-f (5.6 mg, 0.01 mmol), Co2(CO)8 (1.7 mg, 0.005 mmol), substrate (1 mmol), and 3 mL of solvent to a 10 mL hydrogenation inner tube. Seal the tube with parafilm, remove the tube, and seal it in a hydrogenation autoclave. Rapidly replace carbon monoxide three times, then fill the tube with 13 atm of carbon monoxide. Then, add hydrogen to a total pressure of 40 atm, and stir in a 120°C oil bath. After the reaction is complete, return the system to room temperature, vent the air, and open the autoclave. Filter the reaction solution through a burette column. Add n-tridecane as an internal standard. Calculate the turnover number, chemoselectivity, and regioselectivity using GC.

[0201] Table 5: Experimental results of hydroformylation of different vinyl ether substrates

[0202]

[0203]

[0204] a The conversion and selectivity were determined by GC with n-tridecane added as an internal standard.

[0205] A major feature of this system's substrate scope is its ability to catalyze the highly regioselective hydroformylation of vinyl ethers, affording nearly exclusively branched products. Its turnover, chemoselectivity, and regioselectivity significantly surpass those reported in the literature [Cornils, B. New synthesis with carbon monoxide, Springer, 1980, pp. 99-123]. The system exhibits excellent tolerance for both alkyl and aryl vinyl ethers, achieving chemoselectivities exceeding 90% and regioselectivities exceeding 98:2. This reaction provides a novel method for the synthesis of 2-aryl / alkoxypropanals.

[0206] Example 8: High conversion number experiment

[0207]

[0208] Using an in situ generated catalyst: In an argon-filled glove box, add cyclopropane monophosphine ligand II-f (0.01 M in THF), Co2(CO)8 (0.005 M in THF), substrate (1 mmol), and 3 mL of solvent to a 10 mL hydrogenation inner tube. Seal the tube with parafilm and remove the tube. Place the tube in a hydrogenation autoclave. Rapidly replace carbon monoxide three times, then fill the autoclave with 13 atm of carbon monoxide each time. Then, fill the tube with hydrogen to a total pressure of 40 atm, and stir in a 120°C oil bath. After the reaction is complete, return the system to room temperature, vent the air, and open the autoclave. Filter the reaction mixture through a burette column. Add n-tridecane as an internal standard. Calculate the turnover number, chemoselectivity, and regioselectivity using GC.

[0209] Table 6: 1-Hexene Hydroformylation High Conversion Experiment

[0210]

[0211]

[0212] a The conversion and selectivity were determined by GC with n-tridecane added as an internal standard. b The reaction was allowed to proceed for 12 hours. c CO / H2 (60atm, 1:2), reaction for 24 hours. d CO / H2 (80 atm, 1:2), reaction for 72 hours

[0213] An examination of existing monophosphine ligand-cobalt complex-catalyzed olefin hydroformylation systems revealed that catalyst dosages of >1% were often used, and turnovers were generally <100. However, as shown in Table 6, ligand II-f exhibited high catalytic activity for the hydroformylation of 1-hexene. Scale-up to an S / C ratio of 200 showed little impact on catalytic activity. At an S / C ratio of 500, activity was maintained even with an extended reaction time of 12 hours. While activity decreased slightly at an S / C ratio of 1000, a 96% conversion rate and a turnover of 897 were still achieved.

[0214] We noted that increasing the S / C ratio decreased the regioselectivity of the reaction. We speculate that the isomerization rate is higher than the hydroformylation rate, and the increased substrate concentration leads to an increase in the number of isomerized products, resulting in more branched products and a decrease in regioselectivity. To prevent pressure drop caused by syngas depletion, which could lead to catalyst decomposition, and catalyst instability caused by prolonged reaction time, we increased the syngas pressure to 60 or 80 atm and reacted for 72 hours at an S / C ratio of 5000. The product was obtained with a conversion rate of 71%, a turnover number of 60%, and a chemoselectivity of 85%. The turnover number reached 3015, reaching the best level reported in the literature for monophosphine ligand-cobalt catalysts.

[0215] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A cyclopropane monophosphine ligand-cobalt complex, characterized in that: It has the following structural formula: ; （I） Where: R 1 、R 2 is phenyl or substituted phenyl, wherein the substituent in the substituted phenyl is C1-C8 alkyl; R 3 、R 4 is phenyl, substituted phenyl or C1-C8 alkyl, wherein the substituent in the substituted phenyl is C1-C8 alkyl; R 1 、R 2 、R 3 、R 4 It can be the same or different.

2. The cyclopropane monophosphine ligand-cobalt complex according to claim 1, characterized in that The cyclopropane monophosphine ligand-cobalt complex (I) can be a monomer, a dimer or a solvated complex.

3. The method for preparing the cyclopropane monophosphine ligand-cobalt complex according to any one of claims 1 to 2, characterized in that: In tetrahydrofuran, at 25-150°C, cyclopropane monophosphine ligand (II) and the corresponding cobalt salt (1 equivalent) are complexed for 1-48 hours to prepare cyclopropane monophosphine ligand-cobalt complex (I), the reaction formula of which is: 。 4. The method for preparing a cyclopropane monophosphine ligand-cobalt complex according to claim 3, wherein: The preparation method of the cyclopropane monophosphine ligand (II) is as follows: starting from trans-1,2-diarylethene, using NaOH as a base and TEBAC as a phase transfer catalyst, cyclopropanation with bromoform to prepare gem-dibromocyclopropane (III); then using LiBr as an additive, bromine-lithium exchange with n-butyllithium at -100 ° C to obtain monobromocyclopropane (IV); finally, bromine-lithium exchange again and reacting with PR 3 R 4 Cl reaction, borane protection to obtain cyclopropane skeleton monophosphine ligand borane adduct, DABCO deboranization to obtain cyclopropane skeleton monophosphine ligand (II); 。 5. Use of the cyclopropane monophosphine ligand-cobalt complex according to any one of claims 1 to 2 as a catalyst in the hydroformylation of olefins, wherein the reaction equation is: ; where R 5 It is an alkyl group, a substituted alkyl group, or a phenyl group. The alkyl group refers to a straight-chain or branched-chain alkyl group having 1 to 20 carbon atoms. The substituted alkyl group refers to a terminally substituted straight-chain or branched-chain alkyl group having 1 to 20 carbon atoms. The terminal substituent is benzyl, phenethyl, phenylpropyl, allyl, propargyl, hydroxymethyl, aminomethyl, or chloromethyl.

6. The use according to claim 5, characterized in that The cyclopropane monophosphine ligand is complexed with a cobalt precursor in situ to prepare a cyclopropane monophosphine ligand-cobalt complex (I), which is used in the hydroformylation of olefins. The reaction equation is: ; where R 5 It is an alkyl group, a substituted alkyl group, or a phenyl group. The alkyl group refers to a straight-chain or branched-chain alkyl group having 1 to 20 carbon atoms. The substituted alkyl group refers to a terminally substituted straight-chain or branched-chain alkyl group having 1 to 20 carbon atoms. The terminal substituent is benzyl, phenethyl, phenylpropyl, allyl, propargyl, hydroxymethyl, aminomethyl, or chloromethyl.

7. The use according to claim 6, characterized in that The on-site complexation method is as follows: in the solvent required for the hydroformylation reaction, the cyclopropane monophosphine ligand and the corresponding cobalt salt (1 equivalent) are stirred at room temperature under an argon atmosphere for ten minutes.

8. Use of the cyclopropane monophosphine ligand-cobalt complex according to any one of claims 1 to 2 as a catalyst in the highly regioselective hydroformylation of vinyl ether, wherein the reaction equation is: ; where R 6 The substituted alkyl group, phenyl group, or substituted phenyl group refers to a terminally substituted straight-chain or branched alkyl group having 1 to 20 carbon atoms, wherein the terminal substituent is benzyl, phenethyl, phenylpropyl, allyl, propargyl, hydroxymethyl, aminomethyl, or chloromethyl. The substituted phenyl group is a phenyl group substituted with one or more halogens or alkyl groups.

9. The use according to claim 8, characterized in that Cyclopropane monophosphine ligand-cobalt complex (I) was prepared by in situ complexation of cyclopropane monophosphine ligand with cobalt precursor for highly regioselective hydroformylation of vinyl ethers.

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