Method for preparing high-steric-hindrance chiral amines from Z-type high-steric-hindrance imines through asymmetric palladium-catalyzed hydrogenation

A hindered imine, asymmetric technology, applied in the field of asymmetric palladium-catalyzed hydrogenation of Z-type hindered imines to prepare hindered chiral amines, achieving good reaction efficiency, mild conditions, and easy operation

Active Publication Date: 2019-03-01
SHANGHAI JIAO TONG UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For its synthesis research, in addition to the above few simple reports, so far, there is no relevant report using an efficient palladium-catalyzed asymmetric hydrogenation method to synthesize such compounds with high yield and high enantioselectivity

Method used

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  • Method for preparing high-steric-hindrance chiral amines from Z-type high-steric-hindrance imines through asymmetric palladium-catalyzed hydrogenation
  • Method for preparing high-steric-hindrance chiral amines from Z-type high-steric-hindrance imines through asymmetric palladium-catalyzed hydrogenation
  • Method for preparing high-steric-hindrance chiral amines from Z-type high-steric-hindrance imines through asymmetric palladium-catalyzed hydrogenation

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0047] 2aa(R 1 = R 2 = R 3 =CH 3 , R S =C 6 h 5 , PG=Ts p-toluenesulfonyl) preparation

[0048] In a 10mL Schlenck tube, add phosphine ligand L1a (0.006mmol) and palladium trifluoroacetate (1.7mg, 0.005mmol), the system passed through the vacuum line, replaced with nitrogen for 3 times, added freshly distilled degassed acetone, the solution was in Stir at room temperature for 1 hour, and remove the solvent under reduced pressure to obtain a brown solid. After evacuating for 2 hours, add 2 mL of trifluoroethanol solvent, and add this solvent into a vial containing Z-type bulky hindered imine 1aa (0.25 mmol). Put it into an autoclave, and after 6 hydrogen replacements, the initial hydrogen pressure was 1 bar, and the reaction was stirred at room temperature for 24 hours. Cool, release gas carefully, open the autoclave, take out the vial, drain the solvent, detect the conversion by NMR, and obtain the product by column chromatography. Yield 93%, enantiomeric excess 95%. ...

Embodiment 2

[0050] 2aa(R 1 = R 2 = R 3 =CH 3 , R S =C 6 h 5 , PG=Ts) preparation

[0051] In a 10mL Schlenck tube, add phosphine ligand L1b (0.006mmol) and palladium trifluoroacetate (1.7mg, 0.005mmol), the system passed through the vacuum line, replaced with nitrogen for 3 times, added freshly distilled degassed acetone, the solution was in Stir at room temperature for 1 hour, and remove the solvent under reduced pressure to obtain a brown solid. After evacuating for 2 hours, add 2 mL of trifluoroethanol solvent, and add this solvent into a vial containing Z-type bulky hindered imine 1aa (0.25 mmol). Put it into an autoclave, and after 6 hydrogen replacements, the initial hydrogen pressure was 1 bar, and the reaction was stirred at room temperature for 24 hours. Cool, release gas carefully, open the autoclave, take out the vial, drain the solvent, detect the conversion by NMR, and obtain the product by column chromatography. Yield 92%, enantiomeric excess 98%. 2aa: white solid, ...

Embodiment 3

[0053] 2aa(R 1 = R 2 = R 3 =CH 3 , R S =C 6 h 5 , PG=Ts) preparation

[0054] In a 10mL Schlenck tube, add phosphine ligand L1c (0.006mmol) and palladium trifluoroacetate (1.7mg, 0.005mmol), the system passed through the vacuum line, replaced with nitrogen for 3 times, added freshly distilled degassed acetone, the solution was in Stir at room temperature for 1 hour, and remove the solvent under reduced pressure to obtain a brown solid. After evacuating for 2 hours, add 2 mL of trifluoroethanol solvent, and add this solvent into a vial containing Z-type bulky hindered imine 1aa (0.25 mmol). Put it into an autoclave, and after 6 hydrogen replacements, the initial hydrogen pressure was 1 bar, and the reaction was stirred at room temperature for 24 hours. Cool, release gas carefully, open the autoclave, take out the vial, drain the solvent, detect the conversion by NMR, and obtain the product by column chromatography. Yield 86%, enantiomeric excess 91%. 2aa: white solid, ...

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Abstract

The invention relates to the technical field of chemical engineering, particularly to a method for preparing high-steric-hindrance chiral amines from Z-type high-steric-hindrance imines through asymmetric palladium-catalyzed hydrogenation. The method comprises the following step of, in solvent and at certain hydrogen pressure and temperature, hydrogenating the Z-type high-steric-hindrance chiral amines shown as the formula (1) to the high-steric-hindrance chiral amines shown as the formula (2) under catalysis of chiral palladium catalysts, wherein the structural formulas of the formula (1) andthe formula (2) are shown as followings. The method for preparing the high-steric-hindrance chiral amines from the Z-type high-steric-hindrance imines through asymmetric palladium-catalyzed hydrogenation is mild in conditions and simple in operation and can achieve good reaction yield and efficiency as well as high application effects.

Description

technical field [0001] The invention relates to a method in the technical field of chemical industry, in particular to a method for preparing a large-steric hindered chiral amine by asymmetric palladium-catalyzed hydrogenation of a Z-type bulky hindered imine. Background technique [0002] Largely hindered chiral amines (2) are useful skeletons in natural products, active molecules, chiral N-ligands and some drugs, and are also effective chiral intermediates in the synthesis of some natural compounds and drugs , For example, large sterically hindered chiral oxazophos or carbene ligands, molecular motors, inhibitors of DPP-IV and DPP8, and some steroidal compounds, etc. This is a class of basic structures with a wide range of uses. [0003] After searching the literature of the prior art, it is found that the general methods for obtaining such chiral compounds are extraction, resolution, biology or synthesis from chiral raw materials, which have great limitations and are une...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C07C311/16C07C303/40C07C311/29C07C311/17C07C311/19C07C311/20C07D307/22
CPCC07B2200/07C07C311/16C07C311/17C07C311/19C07C311/20C07C311/29C07D307/22
Inventor 张万斌陈建中张振锋李博闻
Owner SHANGHAI JIAO TONG UNIV
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