Synergistic effect of additives on cyclopropanation of olefins
作者:Donghao Cheng、Deshun Huang、Yian Shi
DOI:10.1039/c3ob40751a
日期:——
An efficient cyclopropanation of olefins with Zn(CH2I)2, a catalytic amount of CCl3CO2H, and 1,2-dimethoxyethane at room temperature is described. A wide variety of olefins, including acid-sensitive substrates, can be cyclopropanated in 71–99% yield.
A Novel Class of Tunable Zinc Reagents (RXZnCH<sub>2</sub>Y) for Efficient Cyclopropanation of Olefins
作者:Jon C. Lorenz、Jiang Long、Zhiqiang Yang、Song Xue、Yinong Xie、Yian Shi
DOI:10.1021/jo030312v
日期:2004.1.1
A class of zincreagents (RXZnCH2Y) generated with an appropriate organozinc is very effective for the cyclopropanation of olefins. The reactivity and selectivity of these reagents can be regulated by tuning the electronic and steric nature of the RX group on Zn. A reasonable level of enantioselectivity was obtained for the cyclopropanation of unfunctionalized olefins when a chiral (iodomethyl)zinc