Several borohydride reagents： sodium borohydride, sodium cyanoborohydride, soudium acetoxyborohydride and soudium triacetoxyborohydride were screened, respectively, for the reduction of 7-demethylsinomenine, which wa...Several borohydride reagents： sodium borohydride, sodium cyanoborohydride, soudium acetoxyborohydride and soudium triacetoxyborohydride were screened, respectively, for the reduction of 7-demethylsinomenine, which was an α,β-dicarbonyl compound derived from sinomenine. Highly regio-and stereo-selectivity was acquired when sodium cyanoborohydride or NaBH（OAc）3 was used. The product was structurally confirmed as 7R configuration by NMR, X-ray crystal diffraction analysis. Some preliminary discussion was also made on the mechanism of the selective reduction.展开更多
This article summarizes the achievements of the authors' group in the area of biocatalyst catalyzed organic reactions in recent 10 years. A strain of Geotrichum sp. obtained by screening is capable of stereos...This article summarizes the achievements of the authors' group in the area of biocatalyst catalyzed organic reactions in recent 10 years. A strain of Geotrichum sp. obtained by screening is capable of stereoselectively reducing a number of carbonyl compounds. In many cases, the stereochemistry is complementary with that obtained by baker's yeast. Therefore, this micro organism provides a useful pathway to the preparation of alcohol compounds with specific configurations. On the other hand, a number of plant sources have been screened for oxynitrilases and the hydrocyanation reactions of various arylcarboxaldehydes have been investigated. A “micro aqueous reaction system' was invented, by which a series of novel optically active cyanohydrins were prepared. On this basis, a high through put continuous reaction system has been designed. This paper also describes examples of the syntheses of bio active compounds by using the optically active compounds obtained from the above mentioned catalytic reactions as precursors.展开更多
A catalytic asymmetric total synthesis of(+)-vincamine is presented. Key features of the synthesis include a Pd-catalyzed enantioselective decarboxylative allylation to form the C20 quaternary stereogenic center and a...A catalytic asymmetric total synthesis of(+)-vincamine is presented. Key features of the synthesis include a Pd-catalyzed enantioselective decarboxylative allylation to form the C20 quaternary stereogenic center and a stereoselective iminium reduction to install the critical cis-C20/C21 relative stereochemisty.展开更多
基金the National Natural Science Foundation of China(No.20772056).
文摘Several borohydride reagents： sodium borohydride, sodium cyanoborohydride, soudium acetoxyborohydride and soudium triacetoxyborohydride were screened, respectively, for the reduction of 7-demethylsinomenine, which was an α,β-dicarbonyl compound derived from sinomenine. Highly regio-and stereo-selectivity was acquired when sodium cyanoborohydride or NaBH（OAc）3 was used. The product was structurally confirmed as 7R configuration by NMR, X-ray crystal diffraction analysis. Some preliminary discussion was also made on the mechanism of the selective reduction.
基金theNationalNaturalScienceFoundationofChinaandStateMinistryofScienceandTechnology (No .G2 0 0 0 0 775 0 6)
文摘This article summarizes the achievements of the authors' group in the area of biocatalyst catalyzed organic reactions in recent 10 years. A strain of Geotrichum sp. obtained by screening is capable of stereoselectively reducing a number of carbonyl compounds. In many cases, the stereochemistry is complementary with that obtained by baker's yeast. Therefore, this micro organism provides a useful pathway to the preparation of alcohol compounds with specific configurations. On the other hand, a number of plant sources have been screened for oxynitrilases and the hydrocyanation reactions of various arylcarboxaldehydes have been investigated. A “micro aqueous reaction system' was invented, by which a series of novel optically active cyanohydrins were prepared. On this basis, a high through put continuous reaction system has been designed. This paper also describes examples of the syntheses of bio active compounds by using the optically active compounds obtained from the above mentioned catalytic reactions as precursors.
基金National Natural Science Foundation of China (Nos. 21991114, 21921002 and 21732005) for financial support。
文摘A catalytic asymmetric total synthesis of(+)-vincamine is presented. Key features of the synthesis include a Pd-catalyzed enantioselective decarboxylative allylation to form the C20 quaternary stereogenic center and a stereoselective iminium reduction to install the critical cis-C20/C21 relative stereochemisty.
