A six-membered bimetallic imidazol-4-yl-palladacycle: Synthesis, structure and catalytic activity

Department of Chemistry, Indian Institute of Technology Kanpur, Kanpur-208 016, Uttar Pradesh, India E-mail: garaman@iitk.ac.in Manuscript received 29 June 2018, accepted 10 July 2018 The treatment of 1-methyl-4-iodo-5-phenylthioimidazole (1) with Pd(PPh3)4 leads to the formation of a six membered bimetallic palladium-imidazol-4-yl complex (2). Spectroscopic and crystallographic analysis prove that 2 is made-up of two Pd(PPh3 )I unit connected by two C,N-metallated imidazolyl ligand. The six-membered ring adapts a boat shaped conformation. Catalytic activity of 2 towards Suzuki-Miyaura cross coupling of aryl bromides was evaluated and found to be an efficient precatalyst for the coupling of electron rich, sterically hindered and heteroatom containing aryl bromides