An aqueous salicylaldehyde diamine oxazoline compound and metal complex thereof, and a preparation method and application thereof

Abstract

This invention discloses a chiral salicylaldehyde diamine oxazoline compound with the structural formula shown in formula (1), and discloses its preparation method and the metal complex of the prepared chiral salicylaldehyde diamine oxazoline compound. The metal complex of the chiral salicylaldehyde diamine oxazoline compound can be used to catalyze the deoxygenation reduction reaction of sulfoxide compounds to generate thioether compounds, especially for preparing sterically hindered thioether products, with a product yield of over 90%. The metal complex can also catalyze the epoxidation reaction of olefin compounds, exhibiting higher catalytic activity and requiring less catalyst.

Description

Technical Field

[0001] This invention relates to a salicylaldehyde diamine oxazoline compound and its preparation method, a metal complex of the salicylaldehyde diamine oxazoline compound, and the use of the metal complex as a catalyst. Background Technology

[0002] In the field of redox reaction research, the methodology of transition metal complex catalysis has received widespread attention from academia and industry worldwide, with extensive research on ligands linked to the central metal. Among these, the salen ligand, obtained by condensing alkyl diamines or aryl diamines with salicylaldehyde, is a classic example. It can form complexes with many metals to catalyze many types of reactions [(a)W.Liu, JTGroves.Acc.Chem.Res.2015,48,1727–1735.(b)X.Han,C.Yuan,B.Hou,L,-J.Liu.H.–Y.Li,Y.Liu,Y.Cui.Che]. m.Soc.Rev.,2020,49,6248-6272.(c)MAMalik,OADar,P.Gull,MYWani.AAHashmi.Med.Chem.Commun.,2018,9,409-436]; In 2016, Gao Shuang et al. first reported the phenylenediamine bisoxazoline ligand and characterized its structure [W.Dai,J.Li,G.-S.Li,H.Yang L.-Y.Wang,S.Gao.Org.Lett.,2013,15,4138-4141]; It mainly coordinates with inexpensive metals (Fe, Co, Ni) to form catalysts, and is widely used in asymmetric epoxidation and asymmetric dihydroxylation of olefins. Complexes of other transition metals have also been synthesized and used to catalyze organic reactions. The inventors have synthesized a salicylaldehyde diamine oxazoline compound, which is of great significance in the field of transition metal catalysis.

[0003] Thioether compounds are crucial components in various commercial pharmaceuticals (such as antibiotics) and chemicals (such as fuel additives), playing a vital role in organic synthesis [(a) McGarrigle, EM; Myers, EL; Illa, O.; Shaw, MA; Riches, SL; Aggarwal, VKChem. Rev. 2007, 107, 5841. (b) Rickard, D.; Luther III, GWChem. Rev. 2007, 107, 514.]. The deoxyreduction reaction of sulfoxides, as an important transformation, has considerable practicality in organic synthesis (especially asymmetric synthesis reactions). For example, in asymmetric synthesis reactions, through stereoselective induction, the chiral sulfinyl group can be removed by reducing sulfoxides to thioethers. However, the reduction of sulfoxides involves chemoselectivity issues, and the generation of byproduct thiols limited the application of early methodologies. With the development of organometallic compounds, it is of great significance to add various metals and their complexes or Lewis acids as catalysts to sulfoxide reduction systems to accelerate the reduction reaction. This is especially important for developing more simple, mild, practical and effective sulfoxide reduction systems. Sulfoxide compounds have been widely used in pharmaceutical and other industries [Chen, C.; Li, Y.; Xiao, Y.; Zhu, L.; Cheng, C.; Liu, Y. Chin. J. Org. Chem. 2011, 31, 925]. However, existing sulfoxide reduction systems often face limitations such as side reactions, low yields, difficult post-processing, or harsh reaction conditions [(a) Kukushkin, V.Y. Coord. Chem. Rev. 1995, 139, 375. (b) Firouzabadia, H.; Jamalianb, A. J. Sulfur. Chem. 2008, 29, 53. (b) Shiri, L.; Kazemi, M. Res. Chem. Intermed. 2017, 43, 6007.]. For sterically hindered sulfoxide reduction products, the yield is very low. Therefore, developing efficient, high-yield, and highly chemoselective reduction reactions of sulfoxides catalyzed by inexpensive metals is of great significance. Summary of the Invention

[0004] This invention discloses a salicylaldehyde-diamine oxazoline compound and its preparation method. The compound is prepared by attaching the SP2 carbon atom of the oxazoline ring to the 2-position of bromobenzene, and then attaching the imine group, resulting from the one-sided condensation of salicylaldehyde and the diamine, to the 1-position of bromobenzene. This invention also discloses a metal complex containing the salicylaldehyde-diamine oxazoline compound; and relates to the catalytic activity of this metal complex as a catalyst in reduction reactions, particularly in deoxygenation reductions containing sulfoxide groups.

[0005] This invention is achieved through the following technical solution:

[0006] A salicylaldehyde diamine oxazoline compound has the following structural formula (1):

[0007]

[0008] R 1 R 2 Each of the following groups is H, unsubstituted or substituted by one or more substituents A: C1-C12 alkyl, C5-C12 cycloalkyl, C6-C12 aryl; wherein the substituent A is one or more of C1-C5 alkyl, C1-C5 alkoxy, phenyl, C1-C5 fluoroalkyl, C1-C5 fluoroalkoxy, hydroxyl, and halogen;

[0009] R 1 R 2 When R is a different substituent, 1 R 2 The connected carbon atom is a chiral carbon atom, and the compound shown in formula (1) is a chiral compound containing salicylaldehyde diamine oxazoline.

[0010] Preferred R 1 It is a C1-C12 alkyl, phenyl, or benzyl, more preferably methyl, isopropyl, tert-butyl, phenyl, or benzyl;

[0011] Preferred R 2 It is H or C1-C12 alkyl, more preferably H or methyl.

[0012] R 3 R 4 The following groups, each independently H, are either unsubstituted or substituted with one or more substituents A: C1-C12 alkyl, C5-C12 cycloalkyl, C6-C12 aryl; wherein the substituent A is one or more of C1-C5 alkyl, C1-C5 alkoxy, phenyl, C1-C5 fluoroalkyl, C1-C5 fluoroalkoxy, hydroxyl, and halogen;

[0013] Preferred R 3 R 4 Each of the following is independently H, an unsubstituted C1-C12 alkyl group or a C1-C5 alkyl group substituted with 1-2 C1-C5 alkoxy groups, more preferably R. 3 R 4 Each can be H, methyl, ethyl, isopropyl, or tert-butyl.

[0014] R 5 R 6 R 7 R 8Each of the following is independently H, C1-C4 fluoroalkoxy, F, Cl, nitro, or an unsubstituted or C1-C12 alkyl group substituted with 1-2 C1-C4 alkoxy groups, more preferably R. 5 R 6 R 7 R 8 Each is independently H or C1-C12 alkyl; more preferably R 5 R 6 R 7 R 8 It can be H, methyl, ethyl, isopropyl, or tert-butyl.

[0015] R 9 R 10 Each can be independently H, C1-C12 alkyl, C1-C4 fluoroalkoxy, F, Cl, nitro, C5-C12 cycloalkyl, or C6-C12 aryl;

[0016] Or R 9 R 10 And the two carbons connected thereto form a ring to form a C5-C12 cycloalkyl, C6-C12 aryl, or C5-C12 heterocyclic aryl; the H on the C5-C12 cycloalkyl, C6-C12 aryl, or C5-C12 heterocyclic aryl is not substituted or is substituted by a substituent B, wherein the substituent B is a C1-C5 alkyl, C1-C5 alkoxy, phenyl, hydroxyl, nitro, or halogen;

[0017] Preferred R 9 R 10 Each of the following is independently H, C1-C12 alkyl, C6-C12 aryl, or R. 9 R 10 And the two carbons connected to it form a ring, forming a phenyl or naphthyl group.

[0018] R 11 It is H, an unsubstituted or substituted group A, one of the following: C1-C12 alkyl, C5-C12 cycloalkyl, C6-C12 aryl; wherein the substituent A is C1-C5 alkyl, C1-C5 alkoxy, phenyl, C1-C5 fluoroalkyl, C1-C5 fluoroalkoxy, hydroxyl, or halogen; preferably R 10 It is H or C1-C12 alkyl; more preferably R 11 It can be H, methyl, ethyl, isopropyl, or tert-butyl.

[0019] R 12 R 13 R 14 R 15Each of the following is independently H, an unsubstituted or C1-C12 alkyl group substituted with 1-2 C1-C4 alkoxy groups, a C1-C4 fluoroalkoxy group, F, Cl, Br, nitro group, or an unsubstituted or C5-C12 cycloalkyl group substituted with 1-3 substituent C groups, wherein the substituent C group is a C1-C4 alkyl group or a C1-C4 alkoxy group;

[0020] Preferred R 12 R 13 R 14 R 15 Each of the following is independently H, C1-C12 alkyl, F, Cl or Br; more preferably R. 12 R 14 For H; R 13 R 15 Each of them is independently H, C1-C12 alkyl or Br, more preferably H, Br, methyl, ethyl, isopropyl or tert-butyl.

[0021] R 9 R 10 When the two carbons connected to it form a ring to form a phenyl group, the chemical formula is as follows (1-1):

[0022]

[0023] R 1 R 2 When the substituents are different, the chiral salicylaldehyde diamine oxazoline compound is of high optical purity, which means that it has an enantioselectivity of more than 90%, preferably more than 95%, and more preferably more than 99%.

[0024] The present invention also discloses a method for preparing the salicylaldehyde diamine oxazoline compound represented by formula (1), the method comprising the following steps:

[0025] (a) Under nitrogen protection, the 2-oxazolinylbromobenzene compound shown in formula (2) and the diamine compound shown in formula (3) undergo a coupling reaction in the presence of a catalyst to obtain the compound shown in formula (4).

[0026] (b) Under nitrogen protection, the compound shown in formula (4) and the salicylaldehyde compound shown in formula (5) undergo a condensation reaction to obtain the salicylaldehyde diamine oxazoline compound shown in formula (1).

[0027]

[0028]

[0029] R 1 ~R 15 The definition is as described above.

[0030] The catalyst in step (a) is a transition metal salt, an organophosphorus ligand, or an inorganic base.

[0031] Furthermore, the transition metal salt is a metal salt of Ru, Rh, Pd, or Ir, preferably dichlorotriphenylphosphine palladium;

[0032] The inorganic base may be sodium tert-butoxide or potassium tert-butoxide, preferably sodium tert-butoxide;

[0033] The organophosphine ligand may be triphenylphosphine, tricyclohexylphosphine, 1,2-bis(diphenylphosphine)ethane, or 1,1'-bis(diphenylphosphine)ferrocene, preferably 1,1'-bis(diphenylphosphine)ferrocene.

[0034] The reaction in step (a) is preferably carried out in an organic solvent, which is any one of benzene, carbon tetrachloride, petroleum ether, tetrahydrofuran, dimethylformamide, diethyl ether, dichloromethane, chloroform, toluene, xylene, cyclohexane, n-hexane, n-heptane, dioxane, and acetonitrile, preferably toluene.

[0035] The volume of the organic solvent used in step (a) is 2 to 10 mL / mmol, calculated as the amount of substance of the compound represented by formula (2).

[0036] As a further improvement, the reaction temperature of the coupling reaction in step (a) is from -0°C to 150°C, preferably heated to reflux for the reaction time of 1 hour to 48 hours.

[0037] As a further improvement, in step (a) of the present invention, the molar ratio of the 2-oxazolinylbromobenzene compound shown in formula (2), the diamine compound shown in formula (3), the transition metal inorganic salt, the organophosphine ligand, and the inorganic base is 1:1-5:0.01-1:0.02-2:2-10, preferably 1:1-3:0.01-0.1:0.02-0.1:2-4.

[0038] In step (a), after the reaction is completed, the reaction solution is post-treated to obtain the compound shown in formula (4). The post-treatment method is as follows: the reaction solution is cooled to room temperature, filtered, washed with dichloromethane, concentrated, and then separated by column chromatography to obtain the compound shown in formula (4). The eluent used for column chromatography is a mixed solvent of petroleum ether and ethyl acetate.

[0039] In step (b), the molar ratio of the compound shown in formula (4) to the salicylaldehyde compound shown in formula (5) is 1:1 to 10, preferably 1:1 to 5, and more preferably 1:1 to 2.

[0040] Step (b) may or may not involve adding a catalyst. When a catalyst is added, the catalyst may be a protic acid or a molecular sieve, and the amount of the catalyst used is 1 to 5% of the amount of the compound shown in formula (4).

[0041] Preferred step (b) does not involve adding a catalyst.

[0042] The reaction solvent in step (b) is an organic solvent, preferably methanol or ethanol, more preferably ethanol. The volume of the reaction solvent in step (b) is 2 to 10 mL / mmol, calculated as the amount of the compound represented by formula (4).

[0043] The reaction temperature in step (b) is heated to reflux, and the reaction time is 15 to 30 hours.

[0044] After the reaction in step (b) is completed, the reaction solution is post-treated to obtain the salicylaldehyde diamine oxazoline compound shown in formula (1). The post-treatment method is as follows: the reaction solution is cooled to room temperature, filtered, the filtrate is washed, concentrated, and then separated by column chromatography to obtain the salicylaldehyde diamine oxazoline compound shown in formula (1).

[0045] This invention also discloses a metal complex containing a salicylaldehyde diamine oxazoline compound, wherein the metal complex is formed by combining a salicylaldehyde diamine oxazoline compound with a transition metal salt ME of a transition metal element in the periodic table. n The metal complexes containing salicylaldehyde diamine oxazoline compounds, prepared by complexation reaction, have the following general formula (6):

[0046]

[0047] In equation (6), R 1 -R 15 As mentioned above;

[0048] In formula (6), M is a transition metal such as Fe, Co, Ni, Cu, Ag, Au, Ru, Rh, Pd, Os, or Ir;

[0049] E is any one of the following: halides (F, Cl, Br, I), pseudohalides (cyanides, cyanate, tetrafluoroborate, isocyanate), and anions of carboxylic acids, sulfonic acids, and phosphonic acids (carbonate, formate, acetate, propionate, methanesulfonate, trichloromethylsulfonate, phenylsulfonate, toluenesulfonate, phosphate, hexafluorophosphate).

[0050] n represents the number of E atoms, which can be 0, 1, 2, or 3. When n = 0, it means that M is not connected to E. Generally, when M is a divalent metal cation, the oxidation states of the oxyanion and nitrogen anion are balanced with those of the divalent metal cation, so there is no need to connect it to E.

[0051] R 1 R 2 When R is a different substituent, 1 R 2 The carbon atom connected is a chiral carbon atom. The compound shown in formula (6) is a chiral metal complex containing salicylaldehyde diamine oxazoline compounds, which can be used for chiral catalytic reactions.

[0052] The metal complex containing salicylaldehyde diamine oxazoline compounds was prepared by the following method:

[0053] Under nitrogen protection, the salicylaldehyde diamine oxazoline compound and transition metal salt ME shown in formula (1) n The metal complex containing salicylaldehyde diamine oxazoline compounds as shown in formula (6) is prepared by reacting in an organic solvent for 1 to 20 hours; the organic solvent is ethanol.

[0054] The salicylaldehyde diamine oxazoline compound and transition metal salt ME shown in formula (1) n The molar ratio of the substances is 0.9 to 2.2:1, preferably 0.9 to 1.1:1, and more preferably 1 to 1.1:1.

[0055] The synthesis of metal complexes containing salicylaldehyde diamine oxazoline compounds can be carried out at low or high temperatures, such as -20 to 150°C, preferably at room temperature to reflux temperature.

[0056] The preferred reaction time is 10–15 hours.

[0057] After the reaction was completed, the solvent was evaporated from the reaction solution, and the solution was washed with ethanol, filtered, and dried to obtain a metal complex containing salicylaldehyde diamine oxazoline compounds.

[0058] The present invention also provides the application of the metal complex containing salicylaldehyde diamine oxazoline compound shown in formula (6) as a catalyst in the deoxygenation reduction reaction of sulfoxide compounds.

[0059] When used as a catalyst, the metal complex is preferably used in an amount of 0.001-10 mol%, more preferably 0.1-5 mol%.

[0060] More specifically, the application involves a deoxygenation reduction reaction on the oxygen-sulfur double bond of a sulfoxide compound in the presence of a catalyst to generate a sulfide compound, the reaction being carried out in the presence of at least one metal complex of formula (6) in a catalytic amount.

[0061] Furthermore, the metal complex containing salicylaldehyde diamine oxazoline compounds can be used to catalyze the deoxygenation reduction reaction of sulfoxide compounds to generate sulfoether compounds. The sulfoxide compounds can be dialkyl sulfoxide compounds, alkylaryl sulfoxide compounds, or diaryl sulfoxide compounds, generating corresponding dialkyl sulfoether compounds, alkylaryl sulfoether compounds, or diaryl sulfoether compounds. The sulfoether products catalyzed by the metal complex of this application have high chemoselectivity and yield, and have significant application value.

[0062] Furthermore, the metal complex containing salicylaldehyde diamine oxazoline compounds can serve as a catalyst to catalyze the deoxygenation reduction reaction of sulfoxide compounds in the following reaction formula (i).

[0063]

[0064] Specifically, the deoxygenation reduction reaction of formula (i) is carried out as follows: Under nitrogen protection, the metal complex of the salicylaldehyde diamine oxazoline compound shown in formula (6) and benzenesilane, the sulfoxide compound shown in formula (A) and an organic solvent are stirred and reacted at a temperature of 50-60°C. The reaction liquid is then subjected to column chromatography to obtain the thioether compound shown in formula (B). The molar ratio of the sulfoxide compound shown in formula (A), benzenesilane, and the metal complex of the salicylaldehyde diamine oxazoline compound shown in formula (6) is 1:1-2:0.01-0.1. The organic solvent can be toluene.

[0065] The reaction time is generally 10 to 15 hours.

[0066] In reaction formula (i), among the sulfoxide compounds represented by reactant formula (A), R a R b Each component can be alkyl, cycloalkyl, aryl, heterocyclic aryl, etc.; preferably R. a R b Each can be independently an alkyl group (C1–C20), an aryl group (C6–C12), or a heterocyclic aryl group (C3–C12);

[0067] The H groups on the C1-C20 alkyl groups, C6-C12 aryl groups, and C3-C12 heterocyclic aryl groups are either unsubstituted or substituted by substituent D. Substituent D can be various groups, including but not limited to one or more of the following: C1-C10 alkyl groups, C3-C10 cycloalkyl groups, C1-C10 alkoxy groups, C6-C12 aryl groups, C3-C12 heterocyclic aryl groups, hydroxyl groups, F, Cl, Br, I, nitro groups, amino groups, trifluoromethyl groups, aldehyde groups, carboxyl groups, C2-C5 ester groups, mercapto groups, sulfonic acid groups, silyl groups, and siloxy groups.

[0068] More preferably, R a R bEach of the following is independently a C1-C5 alkyl, C2-C5 ester, phenyl, benzyl, pyridyl, thiophene, or substituted phenyl group, wherein the substituent on the substituted phenyl group is one or more of methyl, methoxy, trifluoromethyl, hydroxymethyl, and Cl.

[0069] Preferred R a R b Each can be independently phenyl, benzyl, pyridyl, thiophene, or a substituted phenyl. This invention relates to R... a R b All of these are sterically hindered aryl or heterocyclic aryl diaryl sulfoxide compounds, which have good reduction effects, and the yield and selectivity of the obtained diaryl sulfide products are better than those of existing technologies.

[0070] Furthermore, the metal complex containing salicylaldehyde diamine oxazoline compounds serves as a catalyst for the epoxidation reaction of olefins in reaction formula (ii) below. Compared to the known literature reports [Inorg. Chem. 2013, 52, 3620-3626] which require 10 mol% of catalyst, only 5 mol% of catalyst is required in this invention, indicating that the catalyst of this invention has higher catalytic activity.

[0071]

[0072] Specifically, the epoxidation reaction of formula (ii) is carried out as follows: Under nitrogen protection, the metal complex of the salicylaldehyde diamine oxazoline compound shown in formula (6) and iodobenzene, the olefin compound shown in formula (C) and an organic solvent are stirred at room temperature, and the reaction liquid is subjected to column chromatography to obtain the epoxy compound shown in formula (D). The molar ratio of the olefin compound shown in formula (C), iodobenzene and the metal complex of the salicylaldehyde diamine oxazoline compound shown in formula (6) is 1:2 to 4:0.01 to 0.1. The organic solvent can be tetrahydrofuran.

[0073] The reaction time is generally 10 to 15 hours.

[0074] In the aforementioned formula (C), R c The group can be alkyl, cycloalkyl, aryl, heterocyclic aryl, etc.; preferably C1-C20 alkyl or C6-C12 aryl; the H group on the C1-C20 alkyl or C6-C12 aryl group is not substituted or is substituted by a substituent E, which can be various groups, including but not limited to alkyl, cycloalkyl, alkoxy, aryl, heterocyclic aryl, hydroxyl, F, Cl, Br, I, nitro, amino, alkoxy, aldehyde, carboxyl, ester, mercapto, sulfonic acid, silyl, siloxy, etc.

[0075] The beneficial effects of this invention are as follows:

[0076] This invention provides a novel salicylaldehyde diamine oxazoline compound.

[0077] This invention also provides an efficient route for synthesizing salicylaldehyde diamine oxazoline compounds, with a total yield of 86% in two steps.

[0078] This invention provides a novel stable metal complex formed by a salicylaldehyde diamine oxazoline compound and transition metals Fe, Co, Ni, Cu, Ag, Au, Ru, Rh, Pd, Os, and Ir.

[0079] This invention also provides the use of the metal complex of the aforementioned salicylaldehyde diamine oxazoline compound as a homogeneous catalyst. The catalyst can be used to prepare thioether compounds via the deoxygenation reduction reaction of the sulfoxide group in organic compounds, particularly for the preparation of sterically hindered thioether products, with yields exceeding 90%. Prior art reports the deoxygenation reduction of diphenyl sulfoxide to diphenyl sulfide in a yield of 48% [Synthetic Communications, 2011, 41, 2251-2255]. In contrast, the catalyst of this invention achieves a diphenyl sulfide yield of 93%.

[0080] The organic compounds prepared by the metal complex catalyst of this invention are active substances or intermediates for the preparation of such substances, and are particularly useful in the production of fragrances and flavorings, pharmaceutical preparations, and agrochemicals. Detailed Implementation

[0081] The technical solution of the present invention will be further described in detail below through specific embodiments:

[0082] The following examples illustrate the present invention. All reactions were carried out in airless nitrogen and degassed solvents. However, this does not limit the scope of the invention.

[0083] In the examples, the diamine compound represented by formula (3) is commercially available, and the 2-oxazolinylbromobenzene compound represented by formula (2) is prepared according to the literature (OrgBiomol Chem, 2009, 7, 1723-1734.).

[0084] Preparation of compound (4):

[0085] Example A1: Preparation of compound A1:

[0086]

[0087] Under nitrogen protection, 2-(4,4-dimethyl-4,5-dihydrooxazol-2-yl)bromobenzene (2.5413 g, 10 mmol, 1.0 equiv) and phenylenediamine (2.1628 g, 20 mmol, 2.0 equiv) were reacted in 20 mL of toluene, PdCl2(PPh3)2 (0.1754 g, 0.25 mmol, 2.5 mol%), 1,1'-bis(diphenylphosphine)ferrocene (0.1663 g, 0.30 mmol, 3.0 mol%), and sodium tert-butoxide (1.9220 g, 20 mmol, 2.0 equiv) at 110 °C for 12 h. After cooling to room temperature, the mixture was filtered, washed with dichloromethane, concentrated, and eluted by column chromatography with petroleum ether:ethyl acetate at a volume ratio of 5:1 to give 2.0820 g (7.4 mmol, 74%) of compound A1 containing oxazolinodiamines.

[0088] 1 H NMR: (400MHz, CDCl3) δ9.90 (s, 1H), 7.76 (t, J = 8.0Hz, 1H), 7.20 (t, J = 5.2Hz, 2H), 7.06 (t, J =7.8Hz,1H),6.86-6.72(m,2H),6.70-6.63(m,2H),4.02(s,2H),3.85(s,2H),1.36(s,6H); 13 C NMR: (100MHz, CDCl3) δ162.2,147.3,143.1,132.0,129.5,127.5,126.7,126.5,118.6,116.0,115.7,112.5,109.5,67.8,28.7.

[0089] HRMS(ESI) calculated for [C 19 H 21 N3O]+requires m / z 282.1601, found m / z282.1600.

[0090] Example A2: Preparation of compound A2:

[0091] Under nitrogen protection, 2-(4-phenyl-4,5-dihydrooxazol-2-yl)bromobenzene (3.0217 g, 10 mmol, 1.0 equiv) and phenylenediamine (2.1628 g, 20 mmol, 2.0 equiv) were reacted in 20 mL of toluene, PdCl2(PPh3)2 (0.1754 g, 0.25 mmol, 2.5 mol%), 1,1'-bis(diphenylphosphine)ferrocene (0.1663 g, 0.30 mmol, 3.0 mol%), and sodium tert-butoxide (1.9220 g, 20 mmol, 2.0 equiv) at 110 °C for 12 h. The mixture was cooled, filtered, washed with dichloromethane, concentrated, and column filtered. The filtrate was eluted with petroleum ether:ethyl acetate at a volume ratio of 5:1 to give 2.2399 g (6.8 mmol, 68%) of compound A2 containing oxazolinodiamines.

[0092] 1 H NMR: (400MHz, CDCl3) δ9.38 (s, 1H), 8.25 (d, J = 7.2Hz, 1H), 8.09 (d, J = 7.6H) z,2H),7.86-7.75(m,1H),7.66-7.54(m,3H),7.48(t,J=7.2Hz,2H),7.40-7 .32(m,4H),6.77(t,J=8.0Hz,1H);5.43(dd,J=10.0Hz,J=8.4Hz,1H),5.33(s,2H),4.84(dd,J=10.0Hz,J=8.8Hz,1H),4.32(dd,J=8.8Hz,J=8.4Hz,1H) 13 C NMR: (100MHz, CDCl3) δ.165.4,142.4,142.2,142.1,139.3,138.8,132.4,131. 9,129.5,128.6,127.7,126.0,125.9,119.2,119.0,118.3,115.2,70.7,73.2.

[0093] HRMS(ESI) calculated for [C 21 H 21 N3O]+requires m / z 330.1601, found m / z330.1598.

[0094]

[0095] Under nitrogen protection, 2-(4-benzyl-4,5-dihydrooxazol-2-yl)bromobenzene (3.1620 g, 10 mmol, 1.0 equiv) and phenylenediamine (2.1628 g, 20 mmol, 2.0 equiv) were reacted in 20 mL of toluene, PdCl2(PPh3)2 (0.1754 g, 0.25 mmol, 2.5 mol%), 1,1'-bis(diphenylphosphine)ferrocene (0.1663 g, 0.30 mmol, 3.0 mol%), and sodium tert-butoxide (1.9220 g, 20 mmol, 2.0 equiv) at 110 °C for 12 h. The mixture was cooled, filtered, washed with dichloromethane, concentrated, and column-eluted with petroleum ether:ethyl acetate at a volume ratio of 5:1 to give 2.6444 g (7.7 mmol, 77%) of compound A3 containing oxazolinodiamines.

[0096] 1H NMR: (400MHz, CDCl3) delta 9.93(s,1H),7.82(d,J=8.0Hz,1H),7.41-7.20(m,7H),7.12(t,J=7.6Hz,1H),6.85-6.80(m,2H),6.80-6.70(m,2H),4.75-4.60( 13C NMR:(100MHz,)delta 164.3,147.3,142.9,138.1,132.3,129.7,129.2,128.5,127.1,126.7,126.4,118.6,116.1,115.8,112.8,109.3,70.2,67.9,42.1;

[0097] HRMS(ESI) calculated for [C 22 H 22 N3O]+requires m / z 344.1757, found m / z344.1757.

[0098]

[0099] Under nitrogen protection, 2-(4-isopropyl-4,5-dihydrooxazol-2-yl)bromobenzene (2.6815 g, 10 mmol, 1.0 equiv) and phenylenediamine (2.1628 g, 20 mmol, 2.0 equiv) were reacted in 20 mL of toluene, PdCl2(PPh3)2 (0.1754 g, 0.25 mmol, 2.5 mol%), 1,1'-bis(diphenylphosphine)ferrocene (0.1663 g, 0.30 mmol, 3.0 mol%), and sodium tert-butoxide (1.9220 g, 20 mmol, 2.0 equiv) at 110 °C for 12 h. The mixture was cooled, filtered, washed with dichloromethane, concentrated, and column filtered. The filtrate was eluted with petroleum ether:ethyl acetate at a volume ratio of 5:1 to give 2.1856 g (7.4 mmol, 74%) of compound A4 containing oxazolinodiamines.

[0100] 1H NMR: (400MHz, CDCl3) delta 9.99(s,1H),7.77(d,J=8.0Hz,1H),7.20(m,2H),7.05(t,J=7.4Hz,1H),6.82(d,J=8.0Hz,1H),6.80-6.73(m,2H),6.69(t,J=7.6Hz,1H),4.3 13C NMR: (100MHz, CDCl3) delta163.8,147.3,142.9,132.1,129.6,126.9,126.9,126.3,118.6,116.1,115.8,112.7,109.5,72.8,68.9,33.2,19.0,18.7;

[0101] HRMS(ESI) calculated for [C 18 H 22 N3O]+requires m / z 296.1757, found m / z296.1756.

[0102]

[0103] Under nitrogen protection, 2-(4-tert-butyl-4,5-dihydrooxazol-2-yl)bromobenzene (2.8218 g, 10 mmol, 1.0 equiv) and phenylenediamine (2.1628 g, 20 mmol, 2.0 equiv) were reacted in 20 mL of toluene, PdCl2(PPh3)2 (0.1754 g, 0.25 mmol, 2.5 mol%), 1,1'-bis(diphenylphosphine)ferrocene (0.1663 g, 0.30 mmol, 3.0 mol%), and sodium tert-butoxide (1.9220 g, 20 mmol, 2.0 equiv) at 110 °C for 12 h. The mixture was cooled, filtered, washed with dichloromethane, concentrated, and column filtered. The filtrate was eluted with petroleum ether:ethyl acetate at a volume ratio of 5:1 to give 2.4442 g (7.9 mmol, 79%) of compound A5 containing oxazolinodiamines.

[0104] 1H NMR: (400MHz, CDCl3) delta 10.04(s,1H),7.77(dd,J=8.0,1.2Hz,1H),7.24-7.18(m,2H),7.04(t,J=7.2Hz,1H),6.80(d,J=8.4Hz,1H),6.76(t,J=7.2Hz ,2H),6.69(t,J=7.6Hz,1H),4.32-4.22(m,1H),4.16-4.06(m,2H),3.82(s,2H),0.93(s,9H); 13CNMR: (100MHz, CDCl3)delta 163.7,147.3,142.7,132.1,129.6,126.8,126.7,126.2,118.5,116.1,115.7,112.7,109.4,76.2,66.9,33.8,25.9;

[0105] HRMS(ESI) calculated for [C 19 H 24 N3O]+requires m / z 310.1914, found m / z310.1911.

[0106]

[0107] Under nitrogen protection, 2-(4-isopropyl-4,5-dihydrooxazol-2-yl)bromobenzene (2.6816 g, 10 mmol, 1.0 equiv) and 1,2-diphenylethylenediamine (4.2458 g, 20 mmol, 2.0 equiv) were reacted in 20 mL of toluene, PdCl2(PPh3)2 (0.1754 g, 0.25 mmol, 2.5 mol%), 1,1'-bis(diphenylphosphine)ferrocene (0.1663 g, 0.30 mmol, 3.0 mol%), and sodium tert-butoxide (1.9220 g, 20 mmol, 2.0 equiv) at 110 °C for 12 h. The mixture was cooled, filtered, washed with dichloromethane, concentrated, and column-eluted with petroleum ether:ethyl acetate at a volume ratio of 5:1 to give 2.4353 g (7.9 mmol, 61%) of compound A6 containing oxazolinidine diamines.

[0108] 1H NMR: (400MHz, CDCl3) delta 9.65(d,J=7.2Hz,1H),7.72(d,J=8.0Hz,1H),7.42(d,J=6.8Hz,2H),7.34-7.18(m,8H),7 .09(t,J=7.8Hz,1H),6.54(t,J=8.0Hz,1H),6.43(d,J=8.0Hz,1H),4.71(dd,J=6.8,4.4Hz ,1H),4.41(t,J=8.4Hz,1H),4.37(d,J=4.8Hz,1H),4.25(q,J=8.4Hz,1H),4.07(t,J=7.2 Hz,1H),2.00-1.84(m,1H),1.65(s,2H),1.19(d,J=6.8Hz,3H),1.08(d,J=6.8Hz,3H); 13C NMR: (100MHz, CDCl3) delta 165.4,149.0,143.5,136.8,131.8,128.5,126.9,126.7,125.9,117.2,113.6,73.5,72.3,71.3,60.4,32.5,19.6;

[0109] HRMS(ESI) calculated for [C 26 H 30 N3O]+requires m / z 400.5381,found m / z400.5382.

[0110] B) Preparation of compound B containing salicylaldehyde diamine oxazoline

[0111] Example B1: Preparation of compound B1 containing salicylaldehyde diamine oxazoline

[0112]

[0113] Under nitrogen protection, A1 (1.4068 g, 5.0 mmol, 1 equiv) and 3,5-di-tert-butylsalicylaldehyde (1.1172 g, 5.0 mmol, 1.0 equiv) were reacted in 10 mL of ethanol at boiling point for 12 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed with dichloromethane, and the filtrate was concentrated and separated by column chromatography (eluting with petroleum ether and ethyl acetate in a volume ratio of 20:1) to give 2.2875 g (4.6 mmol, 92%) of a yellow solid containing a salicylaldehyde diamine oxazoline compound, B1.

[0114] 1H NMR: (400MHz, CDCl3) delta 13.17(s,1H),10.48(s,1H),8.58(s,1H),7.79(d,J=8.0Hz,1H),7.59(d,J=8.0Hz,1H),7.41(t,J=8.4Hz,2H),7.26(t,J=8.4Hz,1H),7.22 13C NMR:(100MHz,)delta 165.3,161.5,158.0,144.7,142.0,140.3,136.7,135.3,131.5,129.8,127.9,126.8,126.6,122.6,120.1,119.6,118.6,117.5,114.4,112.0,67.7,35.0,34.1,31.4,29.4,28.4;

[0115] HRMS(ESI) calculated for [C 32 H 40 N3O2]+requires m / z 498.3115,found m / z498.3114.

[0116]

[0117] Under nitrogen protection, A2 (1.6471 g, 5.0 mmol, 1 equiv) and 3,5-di-tert-butylsalicylaldehyde (1.1172 g, 5.0 mmol, 1.0 equiv) were reacted in 10 mL of ethanol, heated to boiling, and reacted for 12 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed with dichloromethane, and the filtrate was concentrated and separated by column chromatography (eluting with petroleum ether and ethyl acetate in a volume ratio of 20:1) to give 2.5629 g (4.7 mmol, 94%) of a chiral salicylaldehyde-containing diamine oxazoline compound B2.

[0118] 1H NMR:(400MHz,)delta 13.18(s,1H),10.77(s,1H),8.50(s,1H),7.88(d,J=8.0Hz,1H),7.59(d,J=8.0Hz,1 H),7.43(d,J=2.4Hz,1H),7.38(d,J=8.4Hz,1H),7.32(d,J=7.2Hz,1H),7.22(d,J=7. 6Hz,1H),7.15-7.08(m,4H),7.00-7.08(m,4H),6.80(t,J=7.6Hz,1H),5.40(t,J=9. 2Hz,1H),4.66(t,J=9.2Hz,1H),4.10(t,J=8.4Hz,1H),1.42(s,9H),1.33(s,9H); 13C NMR:(100MHz,CDCl3)delta 164.6,164.4,158.1,145.4,142.2,140.3,136.7,135.4,132.1,130.2,128.4,128.2,127.9,127.1,12 6.8,125.3,123.2,121.1,119.5,118.6,117.2,113.4,110.8,72.9,69.9,35.1,34.1,31.5,29.4,29.0;

[0119] HRMS(ESI) calculated for [C 36 H 40 N3O2]+requires m / z 546.3115,found m / z546.3117.

[0120]

[0121] Under nitrogen protection, A3 (1.7172 g, 5.0 mmol, 1 equiv) and 5-bromosalicylic acid aldehyde (1.0051 g, 5.0 mmol, 1.0 equiv) were reacted in 10 mL of ethanol, heated to boiling, and reacted for 12 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed with dichloromethane, and the filtrate was concentrated and separated by column chromatography (eluting with petroleum ether and ethyl acetate in a volume ratio of 20:1) to give 2.2373 g (4.2 mmol, 85%) of a chiral salicylaldehyde diamine oxazoline compound B3.

[0122] 1H NMR:(400MHz,)delta 12.81(s,1H),10.83(s,1H),8.48(s,1H),7.79(d,J=8.4Hz,1H),7.63(d,J=8.4Hz,1H),7.48-7.4 4(m,2H),7.39(dd,J=8.8,2.4Hz,1H),7.34-7.26(m,2H),7.20-7.12(m,4H),7.10-7.00(m,3H),6 .86(d,J=8.8Hz,1H),6.80(t,J=7.6Hz,1H),4.56-4.48(m,1H),4.24(t,J=8.4Hz,1H),4.04(t,J= 8.0Hz, 1H), 2.97 (dd, J=13.6, 5.6Hz, 1H), 2.60 (dd, J=13.6, 5.6Hz, 1H); 13CNMR: (100MHz,) delta 163.8,161.5,159.9,144.4,140.4,138.2,135.9,135.6,134.4,131.9,130.1,129.2,128.4,127.8,126.3,122.6,121.0,119.5,119.2,119.2,117.9,114.0,111.7,110.4,70.4,68.0,42.0;

[0123] HRMS(ESI)calculated for[C29H25BrN3O2]+requires m / z 526.1125,found m / z526.1124.

[0124]

[0125] Under nitrogen protection, A4 (1.4769 g, 5.0 mmol, 1 equiv) and 3,5-di-tert-butylsalicylaldehyde (1.1172 g, 5.0 mmol, 1.0 equiv) were reacted in 10 mL of ethanol at boiling point for 12 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed with dichloromethane, and the filtrate was concentrated and separated by column chromatography (eluting with petroleum ether and ethyl acetate at a volume ratio of 20:1) to give 2.3536 g (4.6 mmol, 93%) of a chiral salicylaldehyde-containing diamine oxazoline compound B4 as a yellow solid.

[0126] 1H NMR: (400MHz, CDCl3) delta 13.12(s,1H),10.77(s,1H),8.60(s,1H),7.80(d,J=7.2Hz,1H),7.61(d,J=8.0Hz,1H),7.46-7.40(m ,2H),7.28(dt,J=8.0,2.0Hz,1H),7.22(dt,J=7.2,1.6Hz,1H),7.19(d,J=2.4Hz,1H),7.15(d,J=8.0 Hz,1H),7.05(t,J=7.2Hz,1H),6.77(t,J=7.2Hz,1H),4.27(t,J=8.0Hz,1H),4.05(q,J=7.6Hz,1H),3 .95(t,J=8.0Hz,1H),1.68-1.56(m,1H),1.43(s,9H),1.32(s,9H),0.73(dd,J=12.8,6.4Hz,6H); 13C NMR:(100MHz,CDCl3)delta 164.7,163.1,158.0,144.9,141.7,140.4,136.7,135.6,131.7,130.0,127.9,127.0,126.8,122.7,1 20.3,119.7,118.8,117.4,113.7,111.5,72.8,68.9,35.1,34.2,33.0,31.5,29.5,27.0,18.9,18.4;

[0127] HRMS(ESI) calculated for [C 33 H 42 N3O2]+requires m / z 512.3272,found m / z512.3271.

[0128]

[0129] Under nitrogen protection, A5 (1.5470 g, 5.0 mmol, 1 equiv) and 3,5-di-tert-butylsalicylaldehyde (1.1172 g, 5.0 mmol, 1.0 equiv) were reacted in 10 mL of ethanol, heated to boiling, and reacted for 12 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed with dichloromethane, and the filtrate was concentrated and separated by column chromatography (eluting with petroleum ether and ethyl acetate in a volume ratio of 20:1) to give 2.3903 g (4.5 mmol, 91%) of a chiral salicylaldehyde-containing diamine oxazoline compound B5 as a yellow solid.

[0130] 1H NMR: (400MHz, CDCl3) delta 13.19(s,1H),10.80(s,1H),8.64(s,1H),7.84(d,J=7.6Hz,1H),7.66(d,J=8.4H z,1H),7.50(d,J=9.2Hz,1H),7.46(d,J=2.4Hz,1H),7.33(d,J=8.4Hz,1H),7.26( d,J=8.0Hz,1H),7.24-7.16(m,2H),7.11(t,J=7.2Hz,1H),6.82(t,J=7.2Hz,1H), 4.26-4.16(m,1H),4.14-4.04(m,2H),1.47(s,9H),1.36(s,9H),0.74(s,9H); 13C NMR:(100MHz,CDCl3)delta 164.7,158.0,145.0,140.3,136.6,135.5,131.6,130.0,127.8,126.9,126.7,122.8,12 0.5,119.8,118.8,117.3,113.5,111.2,76.0,66.9,35.0,34.1,33.5,31.5,29.4,25.6;

[0131] HRMS(ESI) calculated for [C 34 H 44 N3O2]+requires m / z 526.3428,found m / z526.3428.

[0132]

[0133] Under nitrogen protection, A6 (1.9976 g, 5.0 mmol, 1 equiv) and 3,5-di-tert-butylsalicylaldehyde (1.1173 g, 5.0 mmol, 1.0 equiv) were reacted in 10 mL of ethanol at boiling point for 12 h. After the reaction was completed, the mixture was cooled to room temperature, filtered, washed with dichloromethane, and the filtrate was concentrated and separated by column chromatography (eluting with petroleum ether and ethyl acetate at a volume ratio of 20:1) to give 2.8274 g (4.6 mmol, 92%) of a yellow solid containing a salicylaldehyde diamine oxazoline compound, B6.

[0134] 1H NMR: (400MHz, CDCl3) delta 13.39(s,1H),9.56(d,J=5.6Hz,1H),8.45(s,1H),7.73(d,J=7.6Hz,1H),7.44(d,J=2.0Hz,1H),7 .32-7.19(m,10H),7.13(t,J=7.2Hz,1H),7.08(d,J=2.0Hz,1H),6.59(t,J=7.2Hz,1H),6.52(d,J =8.4Hz,1H),5.03(t,J=6.4Hz,1H),4.65(d,J=6.8Hz,1H),4.25(t,J=7.2Hz,1H),4.10-3.98(m,2 13C NMR:(100MHz,CDCl3)delta 167.3,163.6,158.0,148.3,140.7,140.2,140.0,136.6,132.1,129.7,128.2,128.2,128.1,127.7,127.5,127 .2,127.1,126.3,118.1,114.7,111.8,109.3,80.4,72.7,68.1,64.7,35.1,34.2,32.9,31.6,29.5,19.4,18.2;

[0135] HRMS(ESI) calculated for [C 41 H 50 N3O2]+requires m / z 615.3826,found m / z615.3825.

[0136] c) Preparation of metal complex C

[0137] Example C1:

[0138]

[0139] Under nitrogen protection, B1 (0.4974 g, 1.0 mmol, 1.0 equiv) and cobalt acetate (0.1681 g, 0.95 mmol, 0.95 equiv) were heated to boiling in 1.0 mL of anhydrous ethanol and reacted for 12 h. The mixture was then evaporated to dryness, washed with a small amount of ethanol, filtered, and dried to obtain 0.4425 g (0.79 mmol, 84%) of the metal complex C1.

[0140] Anal.Calcd for C 32 H 37 CoN3O2:Found:C,69.30;H,6.72;Co,10.63;N,7.58;O,5.77

[0141] The same method can be used to obtain the following metal complexes (C2-C7).

[0142]

[0143]

[0144] d) Deoxygenation reduction reactions of sulfoxides catalyzed by metal complex C1

[0145] Under nitrogen protection, metal complex C1 (0.025 mmol), toluene (1.0 mL), and benzyl silane (1.0 mmol) were added to a dry reaction tube. After stirring for 10 min, sulfoxide substrate (0.5 mmol) was added, and the mixture was stirred at 50 °C for 12 h. After the reaction was completed, the mixture was cooled to room temperature, diluted with 5 mL of petroleum ether, filtered (eluted with petroleum ether to ethyl acetate at a volume ratio of 10:1), concentrated the filtrate, and separated by column chromatography (eluted with petroleum ether) to obtain the product.

[0146] Example D1: Phenyl methyl sulfide

[0147]

[0148] Oily liquid, 96% yield 1 H NMR: (400MHz, CDCl3) delta 7.32-7.20 (m, 4H), 7.13 (t, J = 6.8Hz, 1H), 2.47 (s, 3H);

[0149] Example D2: 4-Methylphenylmethyl sulfide

[0150]

[0151] Oily liquid, 94% yield, 1H NMR: (400MHz, CDCl3) delta 7.18 (d, J = 8.0Hz, 2H), 7.10 (d, J = 8.0Hz, 2H), 2.46 (s, 3H), 2.31 (s, 3H);

[0152] Example D3: Dibenzyl sulfide

[0153]

[0154] White solid, 94% yield, 1H NMR: (400MHz, CDCl3) delta 7.34-7.20 (m, 10H), 3.59 (s, 4H);

[0155] Example D4: Diphenyl sulfide

[0156]

[0157] Colorless liquid, 93% yield, 1H NMR: (400MHz, CDCl3) delta 7.38-7.30 (m, 5H), 7.30-7.27 (m, 3H), 7.26-7.20 (m, 2H);

[0158] By changing the substrates of different sulfoxide compounds, corresponding thioether compounds were prepared. The yields and NMR data of the thioether compounds prepared with different substrates are shown in Table 1 below:

[0159] Table 1

[0160]

[0161]

[0162]

[0163] e) C1-catalyzed epoxidation of olefins by metal complexes

[0164] At room temperature and under nitrogen protection, metal complex C1 (0.025 mmol), tetrahydrofuran (1.0 mL), iodobenzoylbenzene (1.0 mmol), and styrene compounds (0.5 mmol) were added to a dry reaction tube. The mixture was then stirred at room temperature for 12 h and separated by column chromatography to obtain the product.

[0165] Example E1: (±)-4-chlorostyrene epoxide

[0166]

[0167] Yellow liquid, 82% yield 1H NMR: (400MHz, CDCl3) delta 7.30 (d, J = 8.4Hz, 2H), 7.20 (d, J = 8.4Hz, 2H), 3.85-3.79 (m, 1H), 3.13 (t, J = 4.8Hz, 1H), 2.74 (dd, J = 4.8, 2.0Hz, 1H).

[0168] Example E2: (±)-4-methoxystyrene epoxide

[0169]

[0170] Colorless liquid, 91% yield 1 H NMR: (400MHz, CDCl3) delta 7.20 (d, J = 8.4Hz, 2H), 6.88 (d, J = 8.4Hz, 2H), 3.89-3.76 (m, 4H), 3.15-3.10 (m, 1H), 2.81 (dd, J = 5.2, 2.4Hz, 1H).

[0171] Example E3: (±)-Naphthalenevinyl epoxide

[0172]

[0173] White solid, 86% yield 1 H NMR: (400MHz, CDCl3)delta 7.92-7.76(m,3H),7.55-7.46(m,3H),7.36(dd,J=8.4,2.0Hz,1H),4.06(dd, J=4.0,2.4Hz,1H),3.26(dd,J=5.2,4.0Hz,1H),2.94(dd,J=5.6,2.4Hz,1H).

[0174] F): Comparative experiment on the catalytic performance and reaction conditions of various catalysts.

[0175]

[0176] The metal complex C1 in Example D12 was replaced with C2 to C7, and the reaction conditions remained unchanged. The yield of the obtained 4,4'-dimethyl diphenyl sulfide and the recovery rate of unreacted raw materials are shown in Table 2 below.

[0177] Table 2

[0178]

[0179] a Represents nuclear magnetic resonance yield.

[0180] The results in Table 2 show that the metal complex catalysts C1 to C7 of the present invention have good catalytic activity for the reduction reaction of sterically hindered sulfoxides, and the yield of anisole is higher than that of the prior art.

[0181] The above examples are only some specific embodiments of the present invention. Obviously, the present invention is not limited to the above embodiments and there can be many variations. All variations that can be directly derived or conceived by those skilled in the art from the content disclosed in the present invention should be considered to be within the protection scope of the present invention.

Claims

1. A salicylaldehyde diamine oxazoline compound, with the structural formula shown in formula (1) below: （1）； R 1 It is a C1-C12 alkyl, phenyl, or benzyl group; R 2 It is H or C1-C12 alkyl; R 3 R 4 Each is independently H or C1-C12 alkyl; R 5 R 6 R 7 R 8 Each is independently H or C1-C12 alkyl; R 9 R 10 Each of the following is independently H, C1-C12 alkyl, C6-C12 aryl, or R. 9 R 10 And the two carbons connected to it form a ring, forming a phenyl group; R 11 It is H or C1-C12 alkyl; R 12 R 13 R 14 R 15 Each can be independently H, C1-C12 alkyl, F, Cl or Br.

2. The salicylaldehyde diamine oxazoline compound as described in claim 1, characterized in that... R 1 R 2 When the substituents are different, the compound shown in formula (1) is a chiral salicylaldehyde diamine oxazoline compound, which is of high optical purity, meaning that it has enantioselectivity of more than 90%.

3. The method for preparing the salicylaldehyde diamine oxazoline compound represented by formula (1) as described in claim 1, characterized in that... The method includes the following steps: (a) Under nitrogen protection, the 2-oxazolinylbromobenzene compound shown in formula (2) and the diamine compound shown in formula (3) undergo a coupling reaction in the presence of a catalyst to obtain the compound shown in formula (4); (b) Under nitrogen protection, the compound shown in formula (4) and the salicylaldehyde compound shown in formula (5) undergo a condensation reaction to obtain the salicylaldehyde diamine oxazoline compound shown in formula (1). （2） （3） （4） （5） R 1 ~R 15 The definition is as described in claim 1.

4. A metal complex containing a salicylaldehyde diamine oxazoline compound, said metal complex being formed by reacting the salicylaldehyde diamine oxazoline compound as described in claim 1 with a transition metal salt ME. n The metal complexes containing salicylaldehyde diamine oxazoline compounds, prepared by complexation reaction, have the following general formula (6): （6）； In equation (6), R 1 - R 15 The definition is as described in claim 1; In formula (6), M is a transition metal Fe, Co, Ni, Cu, Ag, Au, Ru, Rh, Pd, Os, or Ir; E is any one of F, Cl, Br, I, CN, cyanate, tetrafluoroborate, isocyanate, carbonate, formate, acetate, propionate, methanesulfonate, trichloromethanesulfonate, phenylsulfonate, toluenesulfonate, phosphate, and hexafluorophosphate. n is the number of E, which can be 0, 1, 2 or 3.

5. The method for preparing the metal complex containing salicylaldehyde diamine oxazoline compounds as described in claim 4, characterized in that... The method is as follows: Under nitrogen protection, the salicylaldehyde diamine oxazoline compound and transition metal salt ME shown in formula (1) n The metal complex containing salicylaldehyde diamine oxazoline compounds as shown in formula (6) is prepared by reacting in an organic solvent for 1 to 20 hours; the organic solvent is ethanol.

6. The application of the metal complex containing salicylaldehyde diamine oxazoline compounds as described in claim 4 as a catalyst in the deoxygenation reduction reaction of sulfoxide compounds in the following reaction formula (i); ； R a R b Each can be independently an alkyl group (C1-C20), an aryl group (C6-C12), or a heterocyclic aryl group (C3-C12); The H group on the C1-C20 alkyl group, C6-C12 aryl group, and C3-C12 heterocyclic aryl group is either unsubstituted or substituted by a substituent D, wherein the substituent D is selected from one or more of the following: C1-C10 alkyl group, C3-C10 cycloalkyl group, C1-C10 alkoxy group, C6-C12 aryl group, C3-C12 heterocyclic aryl group, hydroxyl group, F, Cl, Br, I, nitro group, amino group, trifluoromethyl group, aldehyde group, carboxyl group, C2-C5 ester group, mercapto group, sulfonic acid group, silyl group, and siloxy group.

7. The application as described in claim 6, characterized in that... The deoxygenation reduction reaction of formula (i) is carried out as follows: under nitrogen protection, the metal complex containing salicylaldehyde diamine oxazoline compounds as shown in formula (6) and benzenesilane, the sulfoxide compound as shown in formula (A) and organic solvent are heated at 50-60 °C. o The reaction was stirred at temperature C, and the reaction liquid was subjected to column chromatography to obtain the thioether compound shown in formula (B); R a R b The limitation is as described in claim 6.

8. The application of the metal complex containing salicylaldehyde diamine oxazoline compounds as described in claim 4 as a catalyst in the epoxidation reaction of olefin compounds in the following reaction formula (ii): ； In the aforementioned formula (C), R c It is an alkyl group of C1 to C20 or an aryl group of C6 to C12.

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