carbenoids prepared from 7,7-dibromonorcarane or (2,3-benzocyclohex-2-en-1-ylidene)dichloromethane with butyl-lithium at –85 °C were unreactive at this temperature in tetrahydrofuran (THF) but reacted rapidly with the addition of a stoicheiometric amount of ButOK to give the insertion product with THF, or the addition product with cyclohexane in high yields.
Cyclopropyl carbenoid insertion into alkenylzirconocenes—a convergent synthesis of alkenylcyclopropanes and alkylidenecyclopropanes
作者:Emma Thomas、Alexander N. Kasatkin、Richard J. Whitby
DOI:10.1016/j.tetlet.2006.10.132
日期:2006.12
The insertion of cyclopropyl carbenoids into alkenylzirconocenes, derived by hydrozirconation of terminal alkynes, affords allylzirconium species which react with protons and isonitriles to afford alkenylcyclopropanes, and with aldehydes to afford alkylidene cyclopropanes. The addition of lithium carbenoid to zirconium occurs with the inversion of the organolithium centre. (c) 2006 Elsevier Ltd. All rights reserved.