Enantioselective Cyclopropanation/[1,5]-Hydrogen Shift to Access Rauhut–Currier Product
作者:Seung Tae Kim、Rameshwar Prasad Pandit、Jaesook Yun、Do Hyun Ryu
DOI:10.1021/acs.orglett.0c03937
日期:2021.1.1
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 o-quinone methides proceeds in the presence of chiral oxazaborolidinium ion, providing Z-stereocontrolled Rauhut–Currier products in high yields (up to 96%) with excellent Z/E selectivities (>20:1)
已经开发了迈克尔加成引发的环丙烷化/ [1,5]-氢转移,用于Rauhut-Currier产品的对映选择性合成。α-烷基重氮酸酯与原位生成的邻醌甲基化物的反应在手性恶唑硼烷二鎓离子的存在下进行,可提供高收率(高达96%)的Z-立体控制Rauhut-Currier产品,并具有出色的Z / E选择性(> 20) :1)和对映选择性(最高> 99%ee)。通过将产物转化为具有两个相邻的手性立体中心的3,4-二氢香豆素来说明合成用途。