(E)-α,β-Unsaturated pyrazoleamides undergo facile dienolization to furnish copper(I)-(1Z,3Z)-dienolates as the major in the presence of a copper(I)-(R)-DTBM-SEGPHOS catalyst and EtgN,which react with aldimines to af...(E)-α,β-Unsaturated pyrazoleamides undergo facile dienolization to furnish copper(I)-(1Z,3Z)-dienolates as the major in the presence of a copper(I)-(R)-DTBM-SEGPHOS catalyst and EtgN,which react with aldimines to afford syn-vinylogous products as the major dia-stereoisomers in high regio-and enantioselectivities.In some cases,the diastereoselectivity is low,possibly due to the low ratio of copper(I)-(1Z,3Z)-dienolates to copper(I)-(1Z,3E)-dienolates.展开更多
A novel strategy was developed for a rapid access to the naturally occurring racemic neoclausenamide and its analogs, which featured a highly erythro-selective vinylogous Mukaiyama type reaction （dr= 12：1） and a hi...A novel strategy was developed for a rapid access to the naturally occurring racemic neoclausenamide and its analogs, which featured a highly erythro-selective vinylogous Mukaiyama type reaction （dr= 12：1） and a highly diastereoselective tandem conjugate addition-Davis oxidation ofN-Boc-pyrrol-2（5H）-one 5 （dr= 10：1）. Remarka- bly, the skeleton of neoclausenamide, namely 8n, an analog of neoclausenamide, was built in just two steps with all the four stereogenic centers （relative stereochemistry） established correctly and in excellent diastereoselectivities.展开更多
基金We gratefully acknowledge the financial support from the"Thousand Youth Talents Plan",the National Natural Science Foundation of China(Nos.21672235,21871287,21922114)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XD20000000)+1 种基金CAS Key Laboratory of Synthetic Chemistry of Natural SubstancesShanghai Institute of Organic Chemistry.
文摘(E)-α,β-Unsaturated pyrazoleamides undergo facile dienolization to furnish copper(I)-(1Z,3Z)-dienolates as the major in the presence of a copper(I)-(R)-DTBM-SEGPHOS catalyst and EtgN,which react with aldimines to afford syn-vinylogous products as the major dia-stereoisomers in high regio-and enantioselectivities.In some cases,the diastereoselectivity is low,possibly due to the low ratio of copper(I)-(1Z,3Z)-dienolates to copper(I)-(1Z,3E)-dienolates.
文摘A novel strategy was developed for a rapid access to the naturally occurring racemic neoclausenamide and its analogs, which featured a highly erythro-selective vinylogous Mukaiyama type reaction （dr= 12：1） and a highly diastereoselective tandem conjugate addition-Davis oxidation ofN-Boc-pyrrol-2（5H）-one 5 （dr= 10：1）. Remarka- bly, the skeleton of neoclausenamide, namely 8n, an analog of neoclausenamide, was built in just two steps with all the four stereogenic centers （relative stereochemistry） established correctly and in excellent diastereoselectivities.
