使用新的 (PCN)Ir 配合物作为预催化剂和t BuNH 2作为助催化剂,开发了以乙醇为氢源的 1,3-烯炔的反式半氢化反应。该催化剂体系以高产率和立体选择性提供了一种高效且原子经济地获得不对称 ( E , E )-1,4-二芳基丁二烯的途径。监测过程显示,1,3-烯炔的三键顺式半氢化(形成 ( E , Z )-丁二烯)和 ( E , Z ) 到-( E , E ) 异构化形成( , _E )-丁二烯。
An efficient procedure for regio- and stereoselective synthesis of a series of conjugated enynes by a simple Pd-catalyzed cross-coupling reaction of unactivated ethylenes and ethynyl bromide has been developed. The reaction proceeds smoothly in DMF to give the corresponding products in good to excellent yields. The protocol can tolerate a broad range of functional groups on the substrates. (C) 2011 Elsevier Ltd. All rights reserved.