Department of Chemistry, Sungkyunkwan University, Suwon 16419, Korea.
Org Lett. 2021 Jan 1;23(1):213-217. doi: 10.1021/acs.orglett.0c03937. Epub 2020 Dec 17.
A Michael addition initiated cyclopropanation/[1,5]-hydrogen shift has been developed for the enantioselective synthesis of Rauhut-Currier products. The reaction of α-alkyl diazoesters and in situ generated -quinone methides proceeds in the presence of chiral oxazaborolidinium ion, providing -stereocontrolled Rauhut-Currier products in high yields (up to 96%) with excellent / selectivities (>20:1) and enantioselectivities (up to >99% ee). The synthetic utility was illustrated by conversion of the product to 3,4-dihydrocoumarins with two adjacent chiral stereocenters.
迈克尔加成引发的环丙烷化/[1,5]-氢迁移反应已被开发用于对映选择性合成 Rauhut-Currier 产物。α-烷基重氮酯和原位生成的醌甲醚在手性恶唑硼烷离子的存在下反应，以高收率（高达 96%）、优异的对映选择性（高达>99%ee）提供了具有 - 立体选择性的 Rauhut-Currier 产物。产物转化为具有两个相邻手性中心的 3,4-二氢香豆素，展示了其合成实用性。
