Pd(II)-Catalyzed Olefination of sp3 C−H Bonds

摘要

The Pd-catalyzed Mizoroki Heck reaction, which couples olefinsnwith aryl and vinyl halides and sulfonates, is a uniquely powerfulntransformation for forging C C bonds and plays a pivotal role innmodern organic synthesis.n1nGiven its widespread use, the develop-nment of complementary methods to couple unactivated C H bondsnwith olefins is highly attractive. Indeed, as early as 1967, Fujiwaranand Moritani reported the first example of Pd-mediated C Hnolefination of excess benzene (eq 1).n2nSince then, several researchngroups have sought to expand the synthetic utility of arene C Hnolefination by improving the reactivity, controlling the positionalnselectivity, and using the arene as the limiting reagent; this hasnbeen achieved by exploiting electron-rich heterocycles,n3nproximatendirecting groups,n4nand ligand assistance.n3b,4dnAt the same time,nPd(II)-mediated aryl C H olefination has emerged as an efficientntool for constructing diverse carbon skeletons of natural products.n4d,5