Chlorostyrenes in Iron-Catalyzed Biaryl Coupling Reactions
作者:Samet Gülak、Axel Jacobi von Wangelin
DOI:10.1002/anie.201106110
日期:2012.2.6
An effective protocol for iron‐catalyzed biaryl syntheses by couplingchlorostyrenes with aryl Grignard reagents requires only mild reaction conditions and tolerates various functional groups. The underlying activation of deactivated aryl chlorides proceeds through a rate‐determining coordination of the catalyst to the vinyl substituent and subsequent haptotropic migration along the conjugated π system
cobalt-catalyzed hetero-biaryl couplingreaction between aryl chlorides and arylmagnesium halides with unprecedented selectivity has been developed. The protocol utilizes 1 mol% of cheap Co(acac)3 as pre-catalyst and effects clean reactions of deactivated chlorostyrenes with only 1.1 equiv. of the Grignard reagent under mild conditions (30 °C, 5–30 min). Highly chemoselective reactions were realized even in