Beta-diketone iron catalyst compound as well as synthesis method and application thereof

Abstract

The invention provides a beta-diketone iron catalyst compound as well as a synthesis method and application thereof. The synthesis method comprises the following steps: in a protonic solvent or a mixed solution of a non-protonic solvent and a protonic solvent, under the action of inorganic salt, carrying out a reaction as shown in the specification on a compound 2 and ferric salt to obtain a compound 1. The beta-diketone iron catalyst compound disclosed by the invention can be used as a catalyst, so that an olefin compound is subjected to fragmentation reaction, and C (sp2)-C (sp3) bond oxidation fragmentation reaction of olefin is realized.

Description

Technical Field

[0001] This invention belongs to the field of organic synthesis and catalytic chemistry, specifically relating to a β-diketone iron catalyst compound, its synthesis method, and its uses. Background Technology

[0002] Compared to traditional methods for synthesizing new target compounds through carbon-carbon bonding reactions, there is relatively little research on methods that break chemical bonds at specific positions in a molecule to achieve the formation of new bonds. However, this method has broad application prospects in fields such as the deconstruction and recombination of complex molecular structures, fossil energy utilization, waste polyolefin conversion, and molecular skeleton editing.

[0003] Metal hydride hydrogen atom transfer (MHAT) is an important catalytic reaction system with wide applications in organic synthesis and polymer chemistry. It can achieve reactions such as the hydrogen functionalization of olefins. Different metal-mediated MHAT systems have different reaction characteristics and application scenarios. Among them, the MHAT reaction catalyzed by green and economical iron has attracted much attention, but there are only a few literature reports on ligands for iron catalysts.

[0004] Carbon-carbon double bonds are widely present in natural products, pharmaceutical molecules, and bulk industrial products, such as natural rubber, fatty acids, sterols, and terpenoids. Therefore, the recombination of carbon-carbon double bonds in complex molecules plays a crucial role in synthetic chemistry and drug discovery. For a long time, the methods for breaking and transforming carbon-carbon double bonds have been limited, mainly focusing on oxidation and olefin metathesis reactions to convert carbon-carbon double bonds into carbon-oxygen bonds and new carbon-carbon bonds, respectively. With the continuous development of free radical chemistry, the use of the MHAT reaction to obtain carbon-metal intermediates through the transfer of hydrogen atoms from carbon-carbon double bonds by metal hydrogen species, followed by coupling reactions to achieve hydrogen functionalization of alkenes, has seen significant progress. However, the MHAT pathway for achieving C(sp) functionalization of alkenes... 3 )-C(sp 2 Oxidation reactions involving bond breaking are rarely reported.

[0005] Therefore, there is an urgent need in this field to develop a green and inexpensive metallic iron catalyst that can achieve C(sp) oxidation in olefins under mild conditions. 3 )-C(sp 2 It can accurately identify and efficiently cleave bonds, while also possessing good functional group compatibility and regional selectivity. Summary of the Invention

[0006] This invention aims to develop a green and inexpensive metallic iron catalyst capable of achieving C(sp) oxidation in olefins under mild conditions. 3 )-C(sp 2This invention relates to the accurate identification and efficient cleavage of β-diketone iron catalysts, along with good functional group compatibility and regioselectivity. Specifically, it relates to a β-diketone iron catalyst compound, its synthesis method, and its applications.

[0007] In a first aspect of the invention, a β-diketone iron catalyst compound is provided, said compound having

[0008] The structure shown in Equation 1:

[0009]

[0010] Wherein, R1 is a group selected from the following group: substituted or unsubstituted C1-C5 straight-chain or side-chain alkyl groups, substituted or unsubstituted C3-C5 groups. 10 cycloalkyl, substituted or unsubstituted C6-C 10 Bridged cycloalkyl, substituted or unsubstituted C6-C 10 aryl, substituted or unsubstituted C6-C 10 heteroaryl groups;

[0011] Wherein, substitution refers to the substitution of one or more hydrogen atoms on a group by a substituent selected from the group consisting of: halogen, C1-C3 alkyl, C1-C3 alkoxy, and C1-C3 oxycarbonyl.

[0012] The aforementioned heteroaryl group refers to a heteroatom containing 1 to 4 heteroatoms selected from oxygen, sulfur, and nitrogen.

[0013] In another preferred embodiment, R1 is a group selected from the group consisting of: C1-C5 straight-chain or side-chain alkyl groups, CF3, CBr3, CCl3, etc.

[0014] In another preferred embodiment, the compound has a structure selected from the group consisting of:

[0015]

[0016]

[0017]

[0018] In a second aspect of the invention, a method for preparing the compound described in the first aspect is provided, the method comprising the steps of:

[0019] Compound 2 is prepared by reacting an iron salt with a protic solvent or a mixture of protic and nonprotic solvents in the presence of an inorganic salt.

[0020]

[0021] R1 is defined as described in the first aspect;

[0022] The aprotic solvent is one or more of the following: haloalkanes, ethers, aromatics, and cycloalkanes.

[0023] The protic solvent is one or more of water and alcohol solvents;

[0024] The inorganic salt is selected from the group consisting of: sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, lithium carbonate, cesium carbonate, sodium bicarbonate, potassium bicarbonate, sodium acetate, potassium acetate, or combinations thereof.

[0025] The iron salts mentioned are selected from the group consisting of ferric chloride, ferric bromide, ferric sulfate, ferric nitrate, ferric phosphate, ferric oxalate, and their hydrates.

[0026] In another preferred embodiment, the halocarbon solvent is dichloromethane and / or trichloromethane.

[0027] In another preferred embodiment, the ether solvent is diethyl ether and / or tetrahydrofuran.

[0028] In another preferred embodiment, the aromatic solvent is toluene and / or benzene.

[0029] In another preferred embodiment, the cycloalkane solvent is cyclopentane and / or cyclohexane.

[0030] In another preferred embodiment, the alcohol solvent is methanol and / or ethanol and / or isopropanol and / or tert-butanol.

[0031] In another preferred embodiment, the solvent is a mixture of protic and aprotic solvents, and the volume ratio of the aprotic solvent to the protic solvent is 1:2 to 10.

[0032] In another preferred embodiment, the inorganic salt is selected from the group consisting of sodium hydroxide, lithium hydroxide, sodium carbonate, lithium carbonate, sodium bicarbonate, potassium bicarbonate, sodium acetate, potassium acetate, or combinations thereof.

[0033] In another preferred embodiment, the iron salt is selected from the group consisting of ferric chloride, ferric tribromide, ferric sulfate, ferric phosphate, ferric oxalate, and ferric chloride hexahydrate.

[0034] In another preferred embodiment, the volume molar ratio of the solvent to compound 2 is 10–50 L / mol.

[0035] In another preferred embodiment, the molar ratio of the inorganic salt to compound 2 is 0.5 to 5:1; and / or

[0036] The molar ratio of the iron salt to compound 2 is 1:3 to 8.

[0037] In another preferred embodiment, the iron salt is selected from the group consisting of ferric chloride, ferric bromide, ferric sulfate, ferric nitrate, ferric phosphate, ferric oxalate, and their hydrates.

[0038] In another preferred embodiment, the reaction temperature is 0–80°C; preferably 30–60°C.

[0039] In a third aspect of the invention, there is provided a use of the compound described in the first aspect, the compound being used to catalyze the silanization fragmentation of compound 3 to prepare compounds 4 and 5, the catalysis comprising the following steps:

[0040] In an oxygen-containing atmosphere, compound 3, the silane compound, and the β-diketone iron catalyst compound described in the first aspect are mixed in a solvent and reacted to generate compound 4 and compound 5.

[0041] Wherein, the solvent is a protic solvent, or a mixture of a protic solvent and an aprotic solvent;

[0042]

[0043] R1 is defined as described in the first aspect;

[0044] R2 is selected from the following group: substituted or unsubstituted C1-C6 alkyl groups, substituted or unsubstituted C6-C6 alkyl groups. 10 Aryl, C1-C6 alkoxy, C1-C6 oxycarbonyl, -OTBS, -OTBDPS, substituted or unsubstituted amino, C2-C6 acyl;

[0045] Wherein, substitution refers to the substitution of one or more hydrogen atoms on a group by a substituent selected from the group consisting of: halogen, C1-C3 alkyl, C1-C3 alkoxy, C2-C6 acyloxy, and C2-C6 acyl.

[0046] The aprotic solvent is one or more of the following: haloalkanes, ethers, aromatics, and cycloalkanes.

[0047] The protic solvent is one or more of water and alcohol solvents;

[0048] The silane compounds are selected from the following group: (Me2SiH)2O, PhSi(Oi-Pr)H2, polymethylhydrosiloxane (PMHS), Et3SiH, PhSiH3, Ph2SiH2, diethoxymethylsilane (DEMS), PhMeSiH2.

[0049] In another preferred embodiment, R2 is selected from the group consisting of: -OMe, -OAc, -OTBS, -OTBDPS, -CO2Me, -CH2OAc, -CH2OTBS, -CH2OTBDPS, -NHAc,

[0050]

[0051] X is selected from the following groups: F, Cl, I, OCH3, CH3.

[0052] In another preferred embodiment, compounds 4 and 5 are selected from the following structures:

[0053]

[0054]

[0055] In another preferred embodiment, the halocarbon solvent is dichloromethane and / or trichloromethane.

[0056] In another preferred embodiment, the ether solvent is diethyl ether and / or tetrahydrofuran.

[0057] In another preferred embodiment, the aromatic solvent is toluene and / or benzene.

[0058] In another preferred embodiment, the cycloalkane solvent is preferably cyclopentane and / or cyclohexane.

[0059] In another preferred embodiment, the alcohol solvent is methanol and / or ethanol and / or isopropanol and / or tert-butanol.

[0060] In another preferred embodiment, the solvent is a mixture of protic and aprotic solvents, and the volume ratio of the aprotic solvent to the protic solvent is 1:2 to 10.

[0061] In another preferred embodiment, the volume molar ratio of the solvent to compound 2 is 10–50 L / mol.

[0062] In another preferred embodiment, the molar ratio of compound 1 to compound 3 is 0.05 to 0.3:1.

[0063] In another preferred embodiment, the molar ratio of the silane compound to compound 3 is 1 to 5:1.

[0064] In another preferred embodiment, the molar ratio of compound 1 to compound 3 is 0.05 to 0.25:1.

[0065] In another preferred embodiment, the molar ratio of the silane compound to compound 3 is 1.5 to 4.5:1.

[0066] In another preferred embodiment, the oxygen-containing atmosphere is air or oxygen.

[0067] In another preferred embodiment, the air or oxygen pressure in the fragmentation reaction is 0.8-1.2 atmospheres.

[0068] In another preferred embodiment, the temperature in the fragmentation reaction is 0–60°C, preferably 20–50°C.

[0069] It should be understood that, within the scope of this invention, the above-described technical features of this invention and the technical features specifically described below (such as in the embodiments) can be combined with each other to form new or preferred technical solutions. Due to space limitations, they will not be described in detail here. Detailed Implementation

[0070] Through extensive and in-depth research and numerous experimental screenings, the inventors have unexpectedly developed a β-diketone iron catalyst compound for the first time. This invention achieves precise control over the performance of iron catalysts by designing β-diketone ligands, thereby enabling efficient and highly selective catalytic reaction of inert C(sp) olefins under mild conditions. 3 )-C(sp 2 The oxidative breakage of the ) bond. Based on this, the inventors completed the present invention.

[0071] β-Diketone iron catalysts and their preparation

[0072] This invention provides a class of methods capable of realizing C(sp) in olefins. 3 )-C(sp 2 Accurate identification and efficient cleavage of the bond are achieved through catalysts, as shown in the following formula:

[0073]

[0074] Among them, trivalent iron and 3 ligand molecules together form compound formula 1.

[0075] Wherein, R1 is a group selected from the following group: substituted or unsubstituted C1-C5 straight-chain or side-chain alkyl groups, substituted or unsubstituted C3-C5 groups. 10 cycloalkyl, substituted or unsubstituted C6-C 10 Bridged cycloalkyl, substituted or unsubstituted C6-C 10 aryl, substituted or unsubstituted C6-C 10 heteroaryl groups;

[0076] Wherein, substitution refers to the substitution of one or more hydrogen atoms on a group by a substituent selected from the group consisting of: halogen, C1-C3 alkyl, C1-C3 alkoxy, and C1-C3 oxycarbonyl.

[0077] The aforementioned heteroaryl group refers to a heteroatom containing 1 to 4 heteroatoms selected from oxygen, sulfur, and nitrogen.

[0078] In another preferred embodiment, each R1 in the formula is a group selected from the group consisting of: C1-C5 straight-chain or side-chain alkyl groups, CF3, CBr3, CCl3, etc.

[0079] The compound can be prepared by the following steps:

[0080] Compound 2 is prepared by reacting an iron salt with a protic solvent or a mixture of protic and nonprotic solvents in the presence of an inorganic salt.

[0081]

[0082] The aprotic solvent is one or more of the following: haloalkanes, ethers, aromatics, and cycloalkanes.

[0083] The protic solvent is one or more of water and alcohol solvents;

[0084] The inorganic salt is selected from the group consisting of: sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, lithium carbonate, cesium carbonate, sodium bicarbonate, potassium bicarbonate, sodium acetate, potassium acetate, or combinations thereof.

[0085] The iron salts mentioned are selected from the group consisting of ferric chloride, ferric bromide, ferric sulfate, ferric nitrate, ferric phosphate, ferric oxalate, and their hydrates.

[0086] Olefin oxidative cleavage reaction using β-diketone iron catalysts

[0087] This invention also provides an olefin oxidative cleavage reaction catalyzed by a β-diketone iron catalyst. The reaction includes the following steps:

[0088] In an oxygen-containing atmosphere, compound 3, the silane compound, and the β-diketone iron catalyst compound are mixed in a solvent and reacted to generate compound 4 and compound 5.

[0089] Wherein, the solvent is a protic solvent, or a mixture of a protic solvent and an aprotic solvent;

[0090]

[0091] R1 is defined as described in the first aspect;

[0092] R2 is selected from the following group: substituted or unsubstituted C1-C6 alkyl groups, substituted or unsubstituted C6-C6 alkyl groups. 10Aryl, C1-C6 alkoxy, C1-C6 oxycarbonyl, -OTBS, -OTBDPS, substituted or unsubstituted amino, C2-C6 acyl;

[0093] Wherein, substitution refers to the substitution of one or more hydrogen atoms on a group by a substituent selected from the group consisting of: halogen, C1-C3 alkyl, C1-C3 alkoxy, C2-C6 acyloxy, and C2-C6 acyl.

[0094] The aprotic solvent is one or more of the following: haloalkanes, ethers, aromatics, and cycloalkanes.

[0095] The protic solvent is one or more of water and alcohol solvents;

[0096] The silane compounds are selected from the following group: (Me2SiH)2O, PhSi(Oi-Pr)H2, polymethylhydrosiloxane (PMHS), Et3SiH, PhSiH3, Ph2SiH2, diethoxymethylsilane (DEMS), PhMeSiH2.

[0097] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0098] 1. The iron catalyst of the present invention achieves precise control of iron catalytic performance through the design of β-diketone ligands, providing a new approach for the development of inexpensive metal selective catalysis.

[0099] 2. The catalyst system developed in this invention can accurately identify and efficiently cleave inert C(sp) atoms in olefins under mild reaction conditions. 3 )-C(sp 2 By converting the C–O bond into a new C–O bond, the complex molecular skeleton can be precisely edited, solving the problems of harsh conditions and poor selectivity of traditional methods.

[0100] The present invention is further illustrated below by way of embodiments, but the invention is not limited to the scope of the embodiments described herein. Experimental methods not specifically described in the following embodiments are performed according to conventional methods and conditions, or as selected according to the product instructions. In the following embodiments, calcd for refers to the calculated value, and found refers to the actual value.

[0101] Example 1: Synthesis of Compound 1a

[0102]

[0103] Compound 2a (6.41 g, 30.85 mmol, 5.0 equiv) and Na₂CO₃ (1.96 g, 18.51 mmol, 3.0 equiv) were completely dissolved in a mixed solvent of EtOH:H₂O (v / v = 1:1). FeCl₃ (1.00 g, 6.17 mmol, 1.0 equiv) was then added to the reaction system. The reaction system was heated to 60 °C and stirred for 1 h. The reaction system was cooled to room temperature and then lowered to 0 °C. The solid was filtered off and washed with H₂O to give compound 1a (1.67 g, yield 40%).

[0104] Example 2 Synthesis of Compound 1b

[0105]

[0106] Compound 2b (1.30 g, 10.15 mmol, 3.0 equiv) and NaOH (338 mg, 8.45 mmol, 2.5 equiv) were completely dissolved in a mixed solvent of MeOH:H₂O (v / v = 1:1). Then, FeBr₃ (1.00 g, 3.38 mmol, 1.0 equiv) was added to the reaction system. The reaction system was heated to 50 °C and stirred for 1.5 h. The reaction system was cooled to room temperature and then lowered to 0 °C. The solid was filtered off and washed with H₂O to give compound 1b (591 mg, yield 40%).

[0107] Example 3 Synthesis of Compound 1c

[0108]

[0109] NaOAc (911 mg, 11.1 mmol, 3.0 equiv) was completely dissolved in a mixed solvent of EtOH and H₂O (v / v = 7:1). A dichloromethane solution of compound 2c (2.62 g, 11.1 mmol, 3.0 equiv) was added to the reaction system until the system became homogeneous and transparent. Then, FeCl₃·6H₂O (1.00 g, 3.70 mmol, 1.0 equiv) was added, and the mixture was heated to 60 °C and stirred for 1 h. The reaction system was cooled to room temperature and then lowered to 0 °C. The solid was filtered off and washed with H₂O to give compound 1c (1.80 g, yield 64%).

[0110] Example 4 Synthesis of Compound 1c

[0111]

[0112] NaHCO3 (1.62 g, 10.00 mmol, 4.0 equiv) was completely dissolved in a mixed solvent of MeOH:H2O (v / v = 6:1). A tetrahydrofuran solution of compound 2c (6.27 g, 15.00 mmol, 6.0 equiv) was added to the reaction system until the system became homogeneous and transparent. Then, Fe2(SO4)3 (1.00 g, 2.50 mmol, 1.0 equiv) was added, and the mixture was heated to 70 °C and stirred for 1.5 h. The reaction system was cooled to room temperature and then to 0 °C. The solid was filtered off and washed with H2O to give compound 1c (856 mg, yield 45%).

[0113] Example 5 Synthesis of Compound 1d

[0114]

[0115] NaOAc (1.52 g, 18.52 mmol, 5.0 equiv) was completely dissolved in a mixed solvent of MeOH:H₂O (v / v = 6:1). A chloroform solution of compound 2c (4.09 g, 29.62 mmol, 8.0 equiv) was added to the reaction system until the system became homogeneous and transparent. Then, FeCl₃·6H₂O (1.00 g, 3.70 mmol, 1.0 equiv) was added, and the mixture was heated to 60 °C and stirred for 3 h. The reaction system was cooled to room temperature and then to 0 °C. The solid was filtered off and washed with H₂O to give compound 1d (735 mg, yield 39%).

[0116] Example 6 Synthesis of Compound 1d

[0117]

[0118] KOAc (1.95 g, 19.89 mmol, 3.0 equiv) was completely dissolved in an i-PrOH:H₂O (v / v = 5:1) mixed solvent. A chloroform solution of compound 2d (3.03 g, 19.89 mmol, 3.0 equiv) was added to the reaction system until the system became homogeneous and transparent. Then, FePO₄ (1.00 g, 6.63 mmol, 1.0 equiv) was added, and the mixture was heated to 50 °C and stirred for 1 h. The reaction system was cooled to room temperature and then lowered to 0 °C. The solid was filtered off and washed with H₂O to give compound 1d (1.32 g, 39% yield).

[0119] Example 7 Synthesis of Compound 1e

[0120]

[0121] NaOAc (1.52 g, 18.51 mmol, 3.0 equiv) was completely dissolved in a t-BuOH:H₂O (v / v = 5:1) mixed solvent. A toluene solution of compound 2e (3.78 g, 18.51 mmol, 3.0 equiv) was added to the reaction system until the system became homogeneous and transparent. FeCl₃ (1.00 g, 6.17 mmol, 1.0 equiv) was then added, and the mixture was heated to 70 °C and stirred for 1 h. The reaction system was cooled to room temperature and then to 0 °C. The solid was filtered off and washed with H₂O to give compound 1e (2.67 g, 65% yield).

[0122] Example 8 Synthesis of Compound 1e

[0123]

[0124] NaOAc (911 mg, 11.11 mmol, 3.0 equiv) was completely dissolved in a mixed solvent of EtOH:H₂O (v / v = 7:1). A dichloromethane solution of compound 2e (2.27 g, 11.11 mmol, 3.0 equiv) was added to the reaction system until the system became homogeneous and transparent. Then, FeCl₃·6H₂O (1.00 g, 3.70 mmol, 1.0 equiv) was added, and the mixture was heated to 60 °C and stirred for 1 h. The reaction system was cooled to room temperature and then lowered to 0 °C. The solid was filtered off and washed with H₂O to give compound 1e (1.85 g, 75% yield).

[0125] Example 9 Synthesis of Compound 1f

[0126]

[0127] KHCO3 (1.33 g, 13.31 mmol, 5.0 equiv) was completely dissolved in a mixed solvent of EtOH:H2O (v / v = 7:1). A dichloromethane solution of compound 2f (2.38 g, 10.64 mmol, 4.0 equiv) was added to the reaction system until the system became homogeneous and transparent. Then, Fe2(C2O4)3 (1.00 g, 2.66 mmol, 1.0 equiv) was added, and the mixture was heated to 60 °C and stirred for 1 h. The reaction system was cooled to room temperature and then lowered to 0 °C. The solid was filtered off and washed with H2O to obtain compound 1f (1.35 g, 70% yield).

[0128] Example 10 Synthesis of 1g of compound

[0129]

[0130] NaOAc (2.02 g, 24.69 mmol, 4.0 equiv) was completely dissolved in a mixed solvent of EtOH and H₂O (v / v = 7:1). A chloroform solution of 2 g (5.83 g, 24.69 mmol, 4.0 equiv) of the compound was added to the reaction system until the system became homogeneous and transparent. Then, FeCl₃ (1.00 g, 6.17 mmol, 1.0 equiv) was added, and the mixture was heated to 60 °C and stirred for 1 h. The reaction system was cooled to room temperature and then lowered to 0 °C. The solid was filtered off and washed with H₂O to give 1 g (4.51 g, 96% yield) of the compound.

[0131] Example 11 Synthesis of 1g of compound

[0132]

[0133] LiOH (191 mg, 8.00 mmol, 3.0 equiv) was completely dissolved in a mixed solvent of EtOH and H₂O (v / v = 7:1). A solution of 2 g (2.52 g, 10.68 mmol, 4.0 equiv) of the compound in dichloromethane was added to the reaction system until the system became homogeneous and transparent. Then, Fe₂(C₂O₄)₃ (1.00 g, 2.67 mmol, 1.0 equiv) was added, and the mixture was heated to 50 °C and stirred for 2 h. The reaction system was cooled to room temperature and then to 0 °C. The solid was filtered off and washed with H₂O to give 1 g (1.42 g, 70% yield) of the compound.

[0134] Example 12 Synthesis of Compound 1h

[0135]

[0136] KHCO3 (1.85 g, 18.51 mmol, 5.0 equiv) was completely dissolved in a mixed solvent of EtOH:H2O (v / v = 7:1). A dichloromethane solution of compound 2f (2.52 g, 14.81 mmol, 4.0 equiv) was added to the reaction system until the system became homogeneous and transparent. Then, FeCl3·6H2O (1.00 g, 3.70 mmol, 1.0 equiv) was added, and the mixture was heated to 60 °C and stirred for 2 h. The reaction system was cooled to room temperature and then lowered to 0 °C. The solid was filtered off and washed with H2O. Compound 1h (1.88 g, 75% yield) was given.

[0137] Example 13 Synthesis of Compound 1i

[0138]

[0139] Li₂CO₃ (1.82 g, 24.68 mmol, 4.0 equiv) was completely dissolved in a mixed solvent of EtOH:H₂O (v / v = 7:1). A dichloromethane solution of compound 2i (7.01 g, 24.68 mmol, 4.0 equiv) was added to the reaction system until the system became homogeneous and transparent. Then, FeCl₃ (1.00 g, 6.17 mmol, 1.0 equiv) was added, and the mixture was heated to 60 °C and stirred for 1 h. The reaction system was cooled to room temperature and then to 0 °C. The solid was filtered off and washed with H₂O to obtain compound 1i (4.24 g, yield 76%).

[0140] Example 14 Synthesis of Compound 1j

[0141]

[0142] NaOAc (833 mg, 10.15 mmol, 3.0 equiv) was completely dissolved in a mixed solvent of EtOH:H₂O (v / v = 7:1). A chloroform solution of compound 2j (1.83 g, 10.15 mmol, 3.0 equiv) was added to the reaction system until the system became homogeneous and transparent. Then, FeBr₃ (1.00 g, 3.38 mmol, 1.0 equiv) was added, and the mixture was heated to 60 °C and stirred for 1 h. The reaction system was cooled to room temperature and then to 0 °C. The solid was filtered off and washed with H₂O to obtain compound 1j (1.20 g, 60% yield).

[0143] Example 15 Synthesis of Compound 1j

[0144]

[0145] KOAc (605 mgj, 12.34 mmol, 2.0 equiv) was completely dissolved in a mixed solvent of EtOH:H2O (v / v = 7:1). A dichloromethane solution of compound 2j (4.45 g, 24.68 mmol, 4.0 equiv) was added to the reaction system until the system became homogeneous and transparent. Then, FeCl3 (1.00 g, 6.17 mmol, 1.0 equiv) was added, and the mixture was heated to 60 °C and stirred for 1 h. The reaction system was cooled to room temperature and then lowered to 0 °C. The solid was filtered off and washed with H2O to obtain compound 1j (1.83 g, 50% yield).

[0146] Example 16 Synthesis of Compound 1k

[0147]

[0148] NaOAc (1.52 g, 18.52 mmol, 5.0 equiv) was completely dissolved in a mixed solvent of EtOH:H₂O (v / v = 7:1). A dichloromethane solution of compound 2k (3.93 g, 18.52 mmol, 5.0 equiv) was added to the reaction system until the system became homogeneous and transparent. Then, FeCl₃·6H₂O (1.00 g, 3.70 mmol, 1.0 equiv) was added, and the mixture was heated to 60 °C and stirred for 1 h. The reaction system was cooled to room temperature and then to 0 °C. The solid was filtered off and washed with H₂O to give compound 1k (842 mg, yield 33%).

[0149] Example 17 Synthesis of compounds 4a and 5a

[0150]

[0151] The reaction flask was purged three times with oxygen. Then, compound 3a (35 mg, 0.2 mmol, 1.0 equiv) was added, followed by ethanol to completely dissolve the substrate. Then, compound 1a (14 mg, 0.02 mmol, 0.1 equiv) was added, and the reaction mixture was stirred at room temperature for 15 minutes. PhSiH3 (43 mg, 0.4 mmol, 2.0 equiv) was then added dropwise at a rate of 100 drops per second. The reaction mixture was allowed to react at room temperature for 24 hours. After the reaction was complete, the solution was evaporated to dryness, and column chromatography yielded compound 4a (13.9 mg, 34% yield) and compound 5a (6.2 mg, 15% yield).

[0152] Compound 4a: 1 H NMR (400MHz, CDCl3) δ9.66(t,J=4.0Hz,1H),7.31(t,J=7.5Hz,2H),7.22(t,J=7.3Hz,1H),7.19–7.13(m,2H),3.22 –3.12(m,1H),2.74(dt,J=7.3,1.9Hz,2H),2.38–2.17(m,2H),2.03(s,3H),2.01–1.94(m,1H),1.88–1.77(m,1H). 13 C NMR(126MHz, CDCl3)δ208.4,201.5,142.9,129.0,127.6,127.1,50.8,41.3,39.3,30.11,30.08.HRMS(ESI,m / z):calcd for C 13 H 17 O2[M+H] + 205.1223, found 205.1229.

[0153] Compound 5a: 1 H NMR (400MHz, CDCl3) δ9.66(t,J=4.0Hz,1H),7.31(t,J=7.5Hz,2H),7.22(t,J=7.3Hz,1H),7.19–7.13(m,2H),3.22 –3.12(m,1H),2.74(dt,J=7.3,1.9Hz,2H),2.38–2.17(m,2H),2.03(s,3H),2.01–1.94(m,1H),1.88–1.77(m,1H). 13 C NMR(126MHz, CDCl3)δ208.4,201.5,142.9,129.0,127.6,127.1,50.8,41.3,39.3,30.11,30.08.HRMS(ESI,m / z):calcd for C 13 H 17 O2[M+H] + 205.1223, found 205.1229.

[0154] Example 18 Synthesis of compounds 4a and 5a

[0155]

[0156] The reaction flask was purged three times with oxygen. Then, compound 3a (35 mg, 0.2 mmol, 1.0 equiv) was added, followed by methanol to completely dissolve the substrate. Then, compound 1c (15 mg, 0.02 mmol, 0.1 equiv) was added, and the reaction mixture was stirred at room temperature for 15 minutes. PhSiH3 (43 mg, 0.4 mmol, 2.0 equiv) was then added dropwise at a rate of 100 drops per second. The reaction mixture was allowed to react at room temperature for 24 hours. After the reaction was complete, the solution was evaporated to dryness, and column chromatography yielded compound 4a (14.3 mg, 35% yield) and compound 5a (6.7 mg, 16% yield).

[0157] Example 19 Synthesis of compounds 4b and 5b

[0158]

[0159] The reaction flask was purged three times with oxygen. Then, compound 3b (25.3 mg, 0.2 mmol, 1.0 equiv) was added, followed by methanol and dichloromethane to completely dissolve the substrate. Next, compound 1e (10.6 mg, 0.016 mmol, 0.08 equiv) was added, and the reaction mixture was stirred at room temperature for 15 minutes. Subsequently, Et3SiH (69.6 mg, 0.6 mmol, 3.0 equiv) was added dropwise at a rate of 100 drops per second. The reaction mixture was allowed to react at room temperature for 24 hours. After the reaction was complete, the solution was evaporated to dryness, and column chromatography yielded compounds 4b (9.3 mg, 29% yield) and 5b (6.5 mg, 20% yield).

[0160] Compound 4b: 1 H NMR(400MHz, CDCl3) δ9.79(t,J=2.1,1H),3.75(tt,J=7.0,4.9Hz,1H),3.32(s,3H),2 .63(ddd,J=16.6,6.9,2.5Hz,1H),2.56–2.46(m,3H),2.16(s,3H),1.93–1.74(m,2H). 13 C NMR(126MHz, CDCl3)δ208.2,201.1,75.2,57.0,48.0,38.9,30.1,27.8.HRMS(DART,m / z):calcd for C8H 15 O3[M+H] + 159.1016, found 159.1016.

[0161] Compound 5b: 1 H NMR (400MHz, CDCl3) δ3.82–3.70 (m, 2H), 3.44 (quint, J = 5.8Hz, 1H), 3.34 (s, 3 H),2.51(t,J=7.4Hz,2H),2.16(s,3H),1.91–1.75(m,2H),1.75–1.68(m,2H). 13 CNMR(101MHz,CDCl3)δ208.6,79.6,60.8,56.7,39.0,35.7,30.1,27.0.HRMS(DART,m / z):calcd for C8H 20 O3N[M+NH4] + 178.1438, found 178.1438.

[0162] Example 20 Synthesis of compounds 4b and 5b

[0163]

[0164] The reaction flask was purged three times with oxygen. Then, compound 3b (25.3 mg, 0.2 mmol, 1.0 equiv) was added, followed by the addition of ethanol and dichloromethane to completely dissolve the substrate. Next, 1 g of compound 3b (12.1 mg, 0.016 mmol, 0.08 equiv) was added, and the reaction mixture was stirred at room temperature for 15 minutes. Subsequently, Et3SiH (92.8 mg, 0.8 mmol, 4.0 equiv) was added dropwise at a rate of 100 drops per second. The reaction mixture was allowed to react at room temperature for 24 hours. After the reaction was complete, the solution was evaporated to dryness, and column chromatography yielded compound 4b (7.9 mg, 25% yield) and compound 5b (7.2 mg, 22% yield).

[0165] Example 21 Synthesis of compounds 4c and 5c

[0166]

[0167] The reaction flask was purged three times with oxygen. Then, compound 3c (30.9 mg, 0.2 mmol, 1.0 equiv) was added, followed by the complete dissolution of the substrate with chloroform. Next, compound 1c (15.2 mg, 0.02 mmol, 0.1 equiv) was added, and the reaction mixture was stirred at room temperature for 15 minutes. Ph₂SiH₂ (73.6 mg, 0.4 mmol, 2.0 equiv) was then added dropwise at a rate of 100 drops per second. The reaction mixture was allowed to react at room temperature for 24 hours. After the reaction was complete, the solution was evaporated to dryness and column chromatography yielded compound 4c (14.1 mg, 38% yield) and compound 5c (4.8 mg, 13% yield).

[0168] Compound 4c: 1 H NMR (400MHz, CDCl3) δ9.74(s,1H),3.69(s,3H),2.95–2.85(m,2H),2.62–2.53(m,1H),2.50(t,J=7.3Hz,2H),2.14(s,3H),1.91–1.79(m,2H). 13 C NMR(126MHz, CDCl3)δ207.5,199.8,174.8,52.2,45.8,40.8,38.2,30.1,25.6.HRMS(ESI,m / z):calcdfor C9H 14 NaO4[M+Na] + 209.0784, found 209.0799.

[0169] Compound 5c: 1H NMR (400MHz, CDCl3) δ3.69 (s, 3H), 3.71–3.64 (m, 2H), 2.55 (quint, J = 7.1Hz, 1H), 2.47 (td, J =7.2,2.0Hz,2H),2.14(s,3H),1.96–1.88(m,1H),1.85(q,J=7.4Hz,2H),1.76–1.69(m,1H). 13 C NMR(126MHz, CDCl3)δ208.2,176.4,60.7,51.9,41.6,41.2,35.0,30.1,25.7.HRMS(ESI,m / z):calcd for C9H 16 NaO4[M+Na] + 211.0941, found 211.0951.

[0170] Example 22 Synthesis of compounds 4c and 5c

[0171]

[0172] The reaction flask was purged three times with oxygen. Then, compound 3c (30.9 mg, 0.2 mmol, 1.0 equiv) was added, followed by the addition of methanol and tetrahydrofuran to completely dissolve the substrate. Then, compound 1h (13.5 mg, 0.02 mmol, 0.1 equiv) was added, and the reaction mixture was stirred at room temperature for 15 minutes. Subsequently, (Me₂SiH)₂O (80.4 mg, 0.6 mmol, 3.0 equiv) was added dropwise at a rate of 100 drops per second. The reaction mixture was allowed to react at room temperature for 24 hours. After the reaction was complete, the solution was evaporated to dryness, and column chromatography yielded compound 4c (13.2 mg, 35% yield) and compound 5c (3.8 mg, 10% yield).

[0173] Example 23 Synthesis of compounds 4d and 5d

[0174]

[0175] The reaction flask was purged three times with oxygen. Then, compound 3d (38.1 mg, 0.2 mmol, 1.0 equiv) was added, followed by isopropanol to completely dissolve the substrate. Next, compound 1f (21.8 mg, 0.03 mmol, 0.15 equiv) was added, and the reaction mixture was stirred at room temperature for 15 minutes. PhSi(Oi-Pr)H2 (99.6 mg, 0.6 mmol, 3.0 equiv) was then added dropwise at a rate of 100 drops per second. The reaction mixture was allowed to react at room temperature for 24 hours. After the reaction was complete, the solution was evaporated to dryness and column chromatography yielded compound 4d (14.6 mg, 33% yield) and compound 5d (8.2 mg, 18% yield).

[0176] Compound 4d: 1 H NMR(400MHz, CDCl3)δ9.68(t,J=1.8Hz,1H),7.32–7.27(m,1H),6.98–6.86(m,3H),3.25–3.16(m,1H) ,2.75(dd,J=7.1,1.7Hz,2H),2.38–2.20(m,2H),2.07(s,3H),2.04–1.96(m,1H),1.86–1.76(m,1H). 13 C NMR (126MHz, CDCl3) δ208.1, 200.8, 163.2 (d, J = 247.2Hz), 145.7 (d, J = 7.6Hz), 130.5 (d, J = 7.6Hz), 123.4 (d,J=3.8Hz),114.5(d,J=32.8Hz),114.0(d,J=21.4Hz),50.65,41.18,38.9(d,J=1.9Hz),30.09,29.93. 19 F NMR(376MHz, CDCl3)δ–112.52(td,J=9.2,5.9Hz).HRMS(ESI,m / z):calcd for C 13 H 15 NaFO2[M+Na] + 245.0948, found 245.0955.

[0177] Compound 5d: 1H NMR (400MHz, CDCl3) δ7.30–7.22(m,1H),6.95–6.82(m,3H),3.61–3.53(m,1H),3.50–3.42(m,1H),2.72(tt,J =10.3,5.1Hz,1H),2.35–2.18(m,2H),2.05(s,3H),2.03–1.95(m,1H),1.94–1.86(m,1H),1.84–1.71(m,2H). 13 C NMR (126MHz, CDCl3) δ208.8, 163.2 (d, J = 246.6Hz), 147.1 (d, J = 6.7Hz), 130.2 (d, J = 8.1Hz), 123.5 (d, J = 2.4Hz), 114.5 (d, J = 21.0Hz), 113.6 (d, J = 21.0Hz), 60.7, 41.53, 41.50 (d, J = 0.86Hz), 39.6, 30.1, 30.1. 19 F NMR(376MHz, CDCl3)δ–113.04(td,J=9.3,6.1Hz).HRMS(ESI,m / z):calcd for C 13 H 18 FO2[M+H] + 225.1285, found 225.1293.

[0178] Example 24 Synthesis of compounds 4d and 5d

[0179]

[0180] The reaction flask was purged three times with oxygen. Then, compound 3d (38.1 mg, 0.2 mmol, 1.0 equiv) was added, followed by methanol to completely dissolve the substrate. Then, compound 1b (8.74 mg, 0.02 mmol, 0.2 equiv) was added, and the reaction mixture was stirred at room temperature for 15 minutes. PhSi(Oi-Pr)H2 (99.6 mg, 0.6 mmol, 3.0 equiv) was then added dropwise at a rate of 100 drops per second. The reaction mixture was allowed to react at room temperature for 24 hours. After the reaction was complete, the solution was evaporated to dryness, and column chromatography yielded compound 4d (13.3 mg, 30% yield) and compound 5d (6.8 mg, 15% yield).

[0181] Example 25 Synthesis of compounds 4e and 5e

[0182]

[0183] The reaction flask was purged three times with oxygen. Then, compound 3e (33.8 mg, 0.2 mmol, 1.0 equiv) was added, followed by the addition of ethanol and toluene to completely dissolve the substrate. Next, compound 1i (18.1 mg, 0.02 mmol, 0.1 equiv) was added, and the reaction mixture was stirred at room temperature for 15 minutes. PhMeSiH2 (48.8 mg, 0.4 mmol, 2.0 equiv) was then added dropwise at a rate of 100 drops per second. The reaction mixture was allowed to react at room temperature for 24 hours. After the reaction was complete, the solution was evaporated to dryness and column chromatography yielded compound 4e (13.1 mg, 33% yield) and compound 5e (7.8 mg, 19% yield).

[0184] Compound 4e: 1 H NMR(400MHz, CDCl3) δ9.75(t,J=1.7Hz,1H),4.05(dd,J=11.2,4.9Hz,1H),3.93(dd,J=11.2,6 .4Hz,1H),2.54–2.37(m,4H),2.33–2.26(m,1H),2.13(s,3H),2.02(s,3H),1.67–1.56(m,2H). 13 C NMR(126MHz, CDCl3)δ207.9,201.1,171.0,66.3,46.4,40.8,32.0,30.1,25.1,20.9.HRMS(ESI,m / z):calcd for C 10 H 16 NaO4[M+Na] + 223.0941, found 223.0949.

[0185] Compound 5e: 1 H NMR (400MHz, CDCl3) δ4.04–3.94(m,2H),3.79–3.66(m,2H),2.51(t,J=7.4Hz,2H),2.15(s,3H),2.05(s,3H),1.85–1.75(m,1H),1.73–1.50(m,4H). 13 C NMR(126MHz, CDCl3)δ209.0,171.4,66.9,60.5,41.0,34.3,33.9,30.2,24.8,21.1.HRMS(ESI,m / z):calcd for C 10 H 18 NaO4[M+Na] + 225.1097, found 225.1105.

[0186] Example 26 Synthesis of compounds 4e and 5e

[0187]

[0188] The reaction flask was purged three times with oxygen. Then, compound 3e (33.8 mg, 0.2 mmol, 1.0 equiv) was added, followed by ethanol to completely dissolve the substrate. Then, compound 1h (27.5 mg, 0.04 mmol, 0.2 equiv) was added, and the reaction mixture was stirred at room temperature for 15 minutes. Subsequently, Et3SiH (69.6 mg, 0.6 mmol, 3.0 equiv) was added dropwise at a rate of 100 drops per second. The reaction mixture was allowed to react at room temperature for 24 hours. After the reaction was complete, the solution was evaporated to dryness, and column chromatography yielded compound 4e (11.9 mg, 30% yield) and compound 5e (6.2 mg, 15% yield).

[0189] Example 27 Synthesis of compounds 4f and 5f

[0190]

[0191] The reaction flask was purged three times with oxygen. Then, compound 3f (73.2 mg, 0.2 mmol, 1.0 equiv) was added, followed by methanol to completely dissolve the substrate. Then, compound 1c (15.2 mg, 0.02 mmol, 0.1 equiv) was added, and the reaction mixture was stirred at room temperature for 15 minutes. PhSiH3 (43.2 mg, 0.4 mmol, 2.0 equiv) was then added dropwise at a rate of 100 drops per second. The reaction mixture was allowed to react at room temperature for 24 hours. After the reaction was complete, the solution was evaporated to dryness, and column chromatography yielded compound 4f (24.8 mg, 31% yield) and compound 5f (8.5 mg, 11% yield).

[0192] Compound 4f: 1 H NMR (400MHz, CDCl3) δ9.77(t,J=2.0Hz,1H),7.66–7.60(m,4H),7.47–7.36(m,6H),3.61(dd,J=10.3,4.5Hz,1H),3.49(dd,J=10.3,6.4Hz,1H ),2.58(ddd,J=16.8,7.0,2.2Hz,1H),2.42–2.35(m,1H),2.35–2.30(m,2H),2.21–2.10(m,1H),2.07(s,3H),1.68–1.52(m,2H),1.05(s,9H). 13C NMR(126MHz, CDCl3)δ208.3,202.3,135.7,135.7,133.4,129.9,127.9,66.0,46.6,41.1,35.5,30.0,27.0,25.1,19.3.HRMS(ESI,m / z):calcdfor C 24 H 33 SiO3[M+Na] + 397.2193, found 397.2193.

[0193] Compound 5f: 1 H NMR (400MHz, CDCl3) δ7.68–7.62(m,4H),7.46–7.36(m,6H),3.68(t,J=5.8Hz,2H),3.5 5(t,J=4.0Hz,2H),2.31(t,J=7.1Hz,2H),2.05(s,3H),1.68–1.49(m,5H),1.06(s,9H). 13 C NMR(101MHz, CDCl3)δ209.1,135.8,133.5,129.9,127.9,66.9,61.1,41.3,37.7,35.4,30.0,27.0,25.2,19.4.HRMS(ESI,m / z):calcd for C 24 H 34 SiNaO3[M+Na] + 421.2169, found 421.2169.

[0194] Example 28 Synthesis of compounds 4f and 5f

[0195]

[0196] The reaction flask was purged three times with oxygen. Then, compound 3f (73.2 mg, 0.2 mmol, 1.0 equiv) was added, followed by the addition of methanol and chloroform to completely dissolve the substrate. Next, compound 1f (13.5 mg, 0.02 mmol, 0.1 equiv) was added, and the reaction mixture was stirred at room temperature for 15 minutes. Subsequently, (Me₂SiH)₂O (53.6 mg, 0.4 mmol, 2.0 equiv) was added dropwise at a rate of 100 drops per second. The reaction mixture was allowed to react at room temperature for 24 hours. After the reaction was complete, the solution was evaporated to dryness, and column chromatography yielded compound 4f (22.1 mg, 28% yield) and compound 5f (6.4 mg, 8% yield).

[0197] Example 29 Synthesis of Compound 4g and Compound 5g

[0198]

[0199] The reaction flask was purged three times with oxygen. Then, 3 g of compound (45.3 mg, 0.2 mmol, 1.0 equiv) was added to the flask, followed by the addition of ethanol and dichloromethane to completely dissolve the substrate. Then, compound 1j (23.7 mg, 0.04 mmol, 0.2 equiv) was added, and the reaction mixture was stirred at room temperature for 15 minutes. Subsequently, PhSiH3 (43.2 mg, 0.4 mmol, 2.0 equiv) was added dropwise at a rate of 100 drops per second, and the reaction mixture was allowed to react at room temperature for 24 hours. After the reaction was complete, the solution was evaporated to dryness, and column chromatography yielded 4 g of compound (15.0 mg, 29% yield) and 5 g of compound (8.0 mg, 15% yield).

[0200] Compound 4g: 1 H NMR(400MHz, CDCl3)δ9.78(t,J=2.4Hz,1H),4.24(quint,J=5.7Hz,1H),2.53–2 .47(m,4H),2.15(s,3H),1.88–1.72(m,2H),0.86(s,9H),0.06(d,J=5.4Hz,6H). 13 C NMR(126MHz, CDCl3)δ208.2,201.7,67.0,50.9,38.9,31.2,30.1,25.9,18.1,-4.4,-4.6.HRMS(ESI,m / z):calcd for C 13 H 26 SiNaO3[M+Na] + 281.1543, found 281.1549.

[0201] Compound 5g: 1 H NMR(400MHz, CDCl3) δ3.95(quint,J=5.7Hz,1H),3.82–3.75(m,1H),3.71(dt,J=10.9,5.5Hz,1 H),2.49(t,J=7.5Hz,2H),2.15(s,3H),1.83–1.62(m,4H),0.89(s,9H),0.08(d,J=7.9Hz,6H). 13 C NMR(126MHz, CDCl3)δ208.7,70.3,60.1,39.2,38.3,30.4,30.1,26.0,18.1,-4.4,-4.5.HRMS(ESI,m / z):calcd for C 13 H 28SiNaO3[M+Na] + 283.1700, found 283.1697.

[0202] Example 30 Synthesis of compounds 4h and 5h

[0203]

[0204] The reaction flask was purged three times with oxygen. Then, compound 3h (30.7 mg, 0.2 mmol, 1.0 equiv) was added, followed by methanol and tetrahydrofuran to completely dissolve the substrate. Then, compound 1d (20.4 mg, 0.04 mmol, 0.2 equiv) was added, and the reaction mixture was stirred at room temperature for 15 minutes. Subsequently, PhSiH3 (43.2 mg, 0.4 mmol, 2.0 equiv) was added dropwise at a rate of 100 drops per second, and the reaction mixture was allowed to react at room temperature for 24 hours. After the reaction was complete, the solution was evaporated to dryness, and column chromatography yielded compound 4h (12.0 mg, 32% yield) and compound 5h (5.3 mg, 14% yield).

[0205] Compound 4h: 1 H NMR (400MHz, CDCl3) δ9.72 (dd, J=2.4, 1.6Hz, 1H), 6.08 (brs, 1H), 4.25 (tq, J=10.4, 5.6Hz ,1H),2.68–2.63(m,2H),2.63–2.45(m,2H),2.14(s,3H),1.92(s,3H),1.86–1.74(m,2H); 13 C NMR(101MHz, CDCl3)δ208.7,201.0,170.1,48.9,45.2,40.5,30.2,28.0,23.4; HRMS(DART,m / z):calcd for C9H 16 NO3[M+NH4] + 186.1125; found 186.1126.

[0206] Compound 5h: 1 H NMR(400MHz, CDCl3)δ6.17(d,J=8.8Hz,1H),4.02–3.89(m,1H),3.84(brs,1H),3.64–3.43(m,2H),2.65–2.54 (m,1H),2.54–2.44(m,1H),2.13(s,3H),1.96(s,3H),1.83–1.69(m,3H),1.34(ddt,J=14.0,10.4,3.2Hz,1H); 13C NMR(101MHz, CDCl3)δ209.4,171.7,58.5,46.9,40.8,38.6,30.2,28.3,23.2; HRMS(DART,m / z):calcd forC9H 18 NO3[M+NH4] + 188.1281; found 188.1282.

[0207] Example 31 Synthesis of Compound 4i

[0208]

[0209] The reaction flask was purged three times with oxygen. Then, compound 3i (48.1 mg, 0.2 mmol, 1.0 equiv) was added, followed by methanol to completely dissolve the substrate. Then, compound 1d (15.2 mg, 0.02 mmol, 0.1 equiv) was added, and the reaction mixture was stirred at room temperature for 15 minutes. PhSiH3 (26.6 mg, 0.4 mmol, 2.0 equiv) was then added dropwise at a rate of 100 drops per second. The reaction mixture was allowed to react at room temperature for 24 hours. After the reaction was complete, the solution was evaporated to dryness and column chromatography to give compound 4i (12.3 mg, 23% yield).

[0210] Compound 4i: 1 H NMR(400MHz, CDCl3)δ9.70(t,J=7.6Hz,1H),4.25–4.16(m,4H),2.92(d,J=2.0Hz,2H ),2.53(t,J=7.7Hz,2H),2.24(t,J=7.7Hz,2H),2.14(s,3H),1.26(t,J=7.1Hz,6H). 13 C NMR(126MHz, CDCl3)δ207.0,198.7,170.3,62.1,54.1,47.2,38.9,30.1,27.9,14.1.HRMS(ESI,m / z):calcd for C 13 H 20 NaO6[M+Na] + 295.1152, found 295.1157.

[0211] Example 32 Synthesis of compounds 4j and 5j

[0212]

[0213] The reaction flask was purged three times with oxygen. Then, compound 3j (48.1 mg, 0.2 mmol, 1.0 equiv) was added, followed by the addition of ethanol and chloroform to completely dissolve the substrate. Next, compound 1e (15.2 mg, 0.02 mmol, 0.1 equiv) was added, and the reaction mixture was stirred at room temperature for 15 minutes. PhSiH3 (26.6 mg, 0.4 mmol, 2.0 equiv) was then added dropwise at a rate of 100 drops per second. The reaction mixture was allowed to react at room temperature for 24 hours. After the reaction was complete, the solution was evaporated to dryness and column chromatography yielded compound 4j (13.8 mg, 25% yield) and compound 5j (8.5 mg, 16% yield).

[0214] All documents mentioned in this invention are incorporated herein by reference as if each document were individually incorporated by reference. Furthermore, it should be understood that after reading the foregoing teachings of this invention, those skilled in the art can make various alterations or modifications to this invention, and these equivalent forms also fall within the scope defined by the appended claims.

Claims

1. A β-diketone iron catalyst compound, characterized in that, The compound has the structure shown in Formula 1: Wherein, R1 is a group selected from the following group: substituted or unsubstituted C1-C5 straight-chain or side-chain alkyl groups, substituted or unsubstituted C3-C5 groups. 10 cycloalkyl, substituted or unsubstituted C6-C 10 Bridged cycloalkyl, substituted or unsubstituted C6-C 10 aryl, substituted or unsubstituted C6-C 10 heteroaryl groups; Wherein, substitution refers to the substitution of one or more hydrogen atoms on a group by a substituent selected from the group consisting of: halogen, C1-C3 alkyl, C1-C3 alkoxy, and C1-C3 oxycarbonyl. The aforementioned heteroaryl group refers to a heteroatom containing 1 to 4 heteroatoms selected from oxygen, sulfur, and nitrogen.

2. The compound according to claim 1, characterized in that, In the formula, R1 is a group selected from the following group: C1-C5 straight-chain or side-chain alkyl groups, CF3, CBr3, CCl3, 3. The compound according to claim 1, characterized in that, The compound has a structure selected from the group consisting of:

4. A method for preparing the compound according to claim 1, characterized in that, The method includes the following steps: Compound 2 is prepared by reacting an iron salt with a protic solvent or a mixture of protic and nonprotic solvents in the presence of an inorganic salt. Wherein, R1 is defined as described in claim 1; The aprotic solvent is one or more of the following: haloalkanes, ethers, aromatics, and cycloalkanes. The protic solvent is one or more of water and alcohol solvents; The inorganic salt is selected from the group consisting of: sodium hydroxide, potassium hydroxide, lithium hydroxide, sodium carbonate, potassium carbonate, lithium carbonate, cesium carbonate, sodium bicarbonate, potassium bicarbonate, sodium acetate, potassium acetate, or combinations thereof. The iron salts mentioned are selected from the group consisting of ferric chloride, ferric bromide, ferric sulfate, ferric nitrate, ferric phosphate, ferric oxalate, and their hydrates.

5. The method as described in claim 4, characterized in that, The solvent is a mixture of protic and non-protic solvents, and the volume ratio of the non-protic solvent to the protic solvent is 1:2 to 10.

6. The method as described in claim 4, characterized in that, The molar ratio of the inorganic salt to compound 2 is 0.5 to 5:1; and / or The molar ratio of the iron salt to compound 2 is 1:3 to 8.

7. Use of the compound according to any one of claims 1-3, characterized in that, The compound is used to catalyze the silanization fragmentation of compound 3 to prepare compounds 4 and 5, and the catalysis includes the following steps: Under an oxygen-containing atmosphere, compound 3, the silane compound, and the β-diketone iron catalyst compound of claim 1 are mixed in a solvent and reacted to generate compound 4 and compound 5. Wherein, the solvent is a protic solvent, or a mixture of a protic solvent and an aprotic solvent; Wherein, R1 is defined as described in claim 1; R2 is selected from the following group: substituted or unsubstituted C1-C6 alkyl groups, substituted or unsubstituted C6-C6 alkyl groups. 10 aryl, C1-C6 alkoxy, C1-C6 oxycarbonyl, -OTBS, -OTBDPS, substituted or unsubstituted amino, C2-C6 acyl; Wherein, substitution refers to the substitution of one or more hydrogen atoms on a group by a substituent selected from the group consisting of: halogen, C1-C3 alkyl, C1-C3 alkoxy, C2-C6 acyloxy, and C2-C6 acyl. The aprotic solvent is one or more of the following: haloalkanes, ethers, aromatics, and cycloalkanes. The protic solvent is one or more of water and alcohol solvents; The silane compounds are selected from the following group: (Me2SiH)2O, PhSi(Oi-Pr)H2, polymethylhydrosiloxane (PMHS), Et3SiH, PhSiH3, Ph2SiH2, diethoxymethylsilane (DEMS), PhMeSiH2.

8. The use as described in claim 7, characterized in that, R2 is selected from the following groups: -OMe, -OAc, -OTBS, -OTBDPS, -CO2Me, -CH2OAc, -CH2OTBS, -CH2OTBDPS, -NHAc, X is selected from the following groups: F, Cl, I, OCH3, CH3.

9. The use as described in claim 7, characterized in that, The molar ratio of compound 1 to compound 3 is 0.05 to 0.3:

1.

10. The use as described in claim 7, characterized in that, The molar ratio of the silane compound to compound 3 is 1 to 5:1.

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