Palladium(II)-catalyzed Heck reaction of aryl halides and arylboronic acids with olefins under mild conditions.
A series of general and selective Pd(II)-catalyzed Heck reactions were investigated under mild reaction conditions. The first protocol has been developed employing an imidazole-based secondary phosphine oxide (SPO) ligated palladium complex (6) as a precatalyst. The catalytic coupling of aryl halides and olefins led to the formation of the corresponding coupled products in excellent yields. A variety of substrates, both electron-rich and electron-poor olefins, were converted smoothly to the targeted products in high yields. Compared with the existing approaches employing SPO-Pd complexes in a Heck reaction, the current strategy features mild reaction conditions and broad substrate scope. Furthermore, we described the coupling of arylboronic acids with olefins, which were catalyzed by Pd(OAc)2 and employed N-bromosuccinimide as an additive under ambient conditions. The resulted biaryls have been obtained in moderate to good yields.
Department of Chemistry, National Chung Hsing University, 250 Kuo-Kuang Road, Taichung, Taiwan (R.O.C.).
Tanveer Mahamadali
TM
Shaikh
Fung-E
FE
Hong
Heck reaction; aryl halides; olefins; palladium-complex; phosphine