Catalyst- and steric-controlled alkenylation via chemoselective C–H activation and C–Br activation in Heck reaction of methyl 1-(2-bromoaryl)-3-(2-furyl/thienyl)-5-oxopyrrolidine-2-carboxylates and diethyl 1-(2-bromoaryl)-3-(2-furyl/thienyl)-5-oxopyrrolid

Pd(II)-catalyzed alkenylation of methyl 1-(2-bromoaryl)-3-(2-furyl/thienyl)-5-oxopyrrolidine-2-carboxylate derivatives 1(a–d) resulted in the formation of 3(a–d) exclusively via C–H activation in the heteroaryl moiety. Similar observations were observed for the corresponding diester analogues 4(a–d) to form 5(a–d). Normal Heck reaction, however, was observed in the case of 1(a–f) to furnish 2(a–f) when the reaction was carried out with Pd(0) catalyst generated in situ. Pd(0)-catalyzed vinylation of 4(a–f) via C–Br oxidation, however, failed due to steric reason.