Ruthenium(II)-Catalyzed Cyclization of Oxabenzonorbornenes with Propargylic Alcohols: Formation of Isochromenes
作者:Karine Villeneuve、William Tam
DOI:10.1002/ejoc.200600836
日期:2006.12
The ruthenium-catalyzed cyclization of a propargylic alcohol with an oxabenzonorbornene in methanol leads to an unanticipated isochromene framework. The catalytic cycle to form this product is believed to go through an oxidative cyclization of the two unsaturated partners with the ruthenium catalyst, followed by β-hydride elimination, tautomerization andhydroruthenation. The ruthenacyclobutane thus
炔丙醇与氧杂苯并降冰片烯在甲醇中的钌催化环化导致意外的异色烯骨架。形成该产品的催化循环被认为是通过两个不饱和伙伴与钌催化剂的氧化环化,然后是 β-氢化物消除、互变异构和氢化钌。如此获得的钌环丁烷进一步经历 [2+2] 环化转化以形成钌-卡宾中间体,该中间体通过 [1,3]-醇盐转移进行非典型重排,最后还原消除以产生所需的化合物。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)