Synthesis, Characterization, and Microwave-Promoted Catalytic Activity of Novel Benzimidazole Salts Bearing Silicon-Containing Substituents in Heck-Mizoroki and Suzuki-Miyaura Cross-Coupling Reactions under Aerobic Conditions

Abstract

A number of benzimidazole derivatives (1-8) were synthesized and the catalytic activity of these compounds in a catalytic system including Pd(OAc) <inf>2</inf> and K <inf>2</inf>CO <inf>3</inf> in DMF-H <inf>2</inf>O was evaluated in Heck-Mizoroki and Suzuki-Miyaura cross-coupling reactions of aryl iodides, bromides, and chlorides with styrene and arylboronic acids under microwave irradiation and aerobic conditions. The yields of both the Heck-Mizoroki and the Suzuki-Miyaura cross coupling reactions with aryl iodides and aryl bromides were nearly quantitative. The synthesized 1-substituted benzimidazole (1) and benzimidazole salts (2-8) were identified by 1Hand 13C-NMR and IR spectroscopic methods, and micro analysis. The molecular structure of 7 was also determined by X-ray crystallography. © 2012 Tübitak.