Branched Arylalkenes from Cinnamates: Selectivity Inversion in Heck Reactions by Carboxylates as Deciduous Directing Groups.
Jie TangDagmar HackenbergerLukas J GooßenPublished in: Angewandte Chemie (International ed. in English) (2016)
A decarboxylative Mizoroki-Heck coupling of aryl halides with cinnamic acids has been developed in which the carboxylate group directs the arylation into its β-position before being tracelessly removed through protodecarboxylation. In the presence of a copper/palladium catalyst, both electron-rich and electron-deficient aryl bromides and chlorides bearing numerous functionalities were successfully coupled with broadly available cinnamates, with selective formation of 1,1-disubstituted alkenes. This reaction concept, in which the carboxylate acts as a deciduous directing group, ideally complements traditional 1,2-selective Heck reactions of styrenes.