Enantioselectivity reversion method for allyl substitution reaction catalyzed by Pd

An enantioselective, allyl substitution technology, applied in the field of enantioselective inversion, can solve the problems of poor configuration prediction and low ee value, and achieve the effect of simple operation and wide range

Inactive Publication Date: 2008-03-19
SHANGHAI JIAO TONG UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

The disadvantages are: the configuration of the product is poorly predictable, the ee value is low, and even a racemic product is obtained

Method used

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  • Enantioselectivity reversion method for allyl substitution reaction catalyzed by Pd

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] Alkylation reaction

[0020] Under nitrogen atmosphere, chiral ligand (0.03mmol) and [Pd(η 3 -C 3 h 5 )Cl] 2 (4.60 mg, 12.5 μmol) was dissolved in dry acetonitrile (1 mL) and stirred at room temperature for 1 h. The obtained in-situ catalyst was added into another solution by syringe, which was dissolved in 1,3-diphenylallyl acetate (0.252 g, 1.00 mmol) and anhydrous potassium acetate (0.0020 g, 20 μmol) Dry acetonitrile (2 mL) was formed. Then, dimethyl malonate (0.396 g, 3.00 mmol) and BSA (0.613 g, 3.00 mmol) were added in sequence, and the reaction was monitored by TLC, and the reaction was completed after 0.5 h. Dilute the system (20mL) with diethyl ether, wash with cold saturated NH 4 Cl aqueous solution (25mL), water and saturated brine washing, anhydrous Na 2 SO 4 After drying, the solvent was evaporated under reduced pressure. The residue was obtained by column chromatography (ethyl acetate / petroleum ether=1 / 8). ee value measured on chiral OD-H column...

Embodiment 2

[0023] Alkylation reaction

[0024] Under nitrogen atmosphere, chiral ligand (0.03mmol) and [Pd(η 3 -C 3 h 5 )Cl] 2 (4.60 mg, 12.5 μmol) was dissolved in dry dichloromethane (1 mL) and stirred at room temperature for 1 h. The obtained in-situ catalyst was added into another solution by syringe, which was dissolved in 1,3-diphenylallyl acetate (0.252 g, 1.00 mmol) and anhydrous potassium acetate (0.0020 g, 20 μmol) Dry dichloromethane (2 mL) formed. Cool down to -78°C, then add dimethyl malonate (0.396g, 3.00mmol) and BSA (0.613g, 3.00mmol) in sequence, and monitor the completion of the reaction by TLC. Dilute the system (20mL) with diethyl ether, wash with cold saturated NH 4 Cl aqueous solution (25mL), water and saturated brine washing, anhydrous Na 2 SO 4 After drying, the solvent was evaporated under reduced pressure. The residue was obtained by column chromatography (ethyl acetate / petroleum ether=1 / 8). ee value measured on chiral OD-H column: 72.9%

[0025] 1 H...

Embodiment 3

[0027] Amination reaction

[0028] Under nitrogen atmosphere, chiral ligand (0.015mmol) and [Pd(η 3 -C 3 h 5 )Cl] 2 (2.3 mg, 0.0063 mmol) was dissolved in dry toluene (1 mL) and stirred at room temperature for 1 h to prepare the in situ catalyst. To this was added a solution of 1,3-diphenylallyl acetate (126 mg, 0.5 mmol) and dry toluene (1 mL). After 10 min, benzylamine (131 μL, 1.5 mmol) was added, the reaction was monitored by TLC, and the reaction was completed after 20 min. Dilute the system (20mL) with diethyl ether, wash with cold saturated NH 4 Cl aqueous solution (25mL), water and saturated brine washing, anhydrous Na 2 SO 4 After drying, the solvent was evaporated under reduced pressure. The residue was obtained by column chromatography (ethyl acetate / petroleum ether=1 / 10). Chiral OJ-H column measurement ee value: 63.1 ~ 70.1%.

[0029] 1 H NMR (400MHz, CDCl 3 ): δ3.75-3.81 (m, 2H), 4.41 (d, J = 7.6Hz, 1H), 6.32 (dd, J = 7.6, 15.6Hz, 1H), 6.58 (d, J = 16H...

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Abstract

The invention relates to a method of enantioselective reversion in the Pd-catalyzed allylic substitution reaction in the field of chemical technique. Metallocene diphosphine ligand with the same chiral skeleton is applied to the Pd-catalyzed allylic asymmetric substitution reaction of 1, 3-diphenyl allyl acetate, and the used nucleophile is dimethyl malonate or benzylamine. When the group at the ortho position of diphenylphosphine is ester group, a S-shaped product is produced by catalysis. If the ester group is reduced into hydroxymethyl group, then a R-shaped product is induced, and the etherified or esterified hydroxyl group has the same inductive function. The method has the advantages of convenient operation, convenient spatial configuration of predicted products and wide screenable range.

Description

technical field [0001] The invention relates to a method in the technical field of chemical industry, in particular to a method for enantioselective inversion in a Pd-catalyzed allyl substitution reaction. Background technique [0002] In asymmetric catalytic reactions, the steric factors of ligands have a great influence on the absolute configuration and enantioselectivity of products. To obtain products with two different configurations, the common method is to synthesize two ligands with opposite configurations. Due to the asymmetry of nature itself, there are often enough chiral sources for one configuration, but it is difficult to obtain another configuration, which makes the application of this method very limited. Therefore, chemists have been working on the study of enantioselective inversion by changing other factors while keeping the configuration of the original ligand (chiral skeleton) unchanged. Among them, simple structural modification of the original chiral...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C67/293C07C69/145B01J31/24B01J31/12
CPCC07B2200/07B01J2531/824B01J31/2409B01J2231/44C07C211/28C07C209/16B01J2531/0263C07C67/343
Inventor 张万斌谢芳刘德龙
Owner SHANGHAI JIAO TONG UNIV
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