Cobalt-Catalyzed Reductive Coupling of Saturated Alkyl Halides with Activated Alkenes
作者:Paritosh Shukla、Yun-Chu Hsu、Chien-Hong Cheng
DOI:10.1021/jo052065w
日期:2006.1.1
efficient cobalt-catalyzed reductive coupling reaction of alkyl halides with electron-withdrawing alkenes (CH2CR1EWG, EWG = electron-withdrawing group) in the presence of water and zinc powder in acetonitrile to give the corresponding Michael-type addition product (RCH2CR1EWG) was described. The methodology is versatile such that unactivated primary, secondary, and tertiary alkyl bromides and iodides and
在乙腈中存在水和锌粉的情况下,卤代烷与吸电子烯烃(CH 2 CR 1 EWG,EWG =吸电子基团)的有效钴催化还原偶联反应,得到相应的迈克尔型加成产物(描述了RCH 2 CR 1 EWG)。该方法学是通用的,使得未活化的伯,仲和叔烷基溴化物和碘化物以及包括丙烯酸酯,丙烯腈,甲基乙烯基酮和乙烯基砜在内的各种共轭烯烃都成功地参与了该偶联反应。对于反应中使用的烷基卤,与相应的溴化物相比,碘化物的收率通常更高。这是采用CoI的独特方法2 dppe,锌和烷基卤化物,可高收率地提供共轭加成产物。从机理上讲,该反应似乎遵循氧化加成驱动的路线,而不是先前报道的自由基路线。