Pd-Catalyzed beta-Selective C-H Arylation of Thiophenes with Triarylantimony Difluorides

摘要

Regioselective C-H arylation using pentavalent organoantimony compounds as a new class of arylating reagents is described. The reaction of thiophenes with triarylantimony difluorides in the presence of 5 mol% of Pd(OAc)2 and 2 equiv. CuCl2 at 80 degrees C under aerobic conditions afforded the beta-arylated thiophene derivatives in moderate-to-high yields. The reaction is sensitive to the electronic nature of the triarylantimony difluorides - those bearing an electron-donating group on the phenyl ring showed higher reactivity than those have an electron-withdrawing group.