Theoretical Investigation on the Mechanism of the CuI-Catalyzed Carbon−Nitrogen Coupling Reaction of 2-Iodo-selenophene with Benzamide

Abstract

The mechanism of the carbon-nitrogen coupling reaction of 2-iodo-selenophene with benzamide catalyzed by CuI has been investigated with density functional theory at the GGA/PW91/DND and GGA/PBE/DNP levels. The geometric configurations of the reactants, intermediates, transition states, and products were optimized and verified by means of vibration frequency calculations. A four-step mechanism was proposed for the reaction. The first step was the rate-control step. Two possible pathways in the fourth step were investigated, and the main pathway was identified by comparing their activation and dissociation energies. For comparison, the same calculations were performed to the reaction without the CuI activator. The activation barrier with CuI is 76 kJ mol(-1) smaller than that without CuI. It turns out that CuI can promote the reaction by lowering the activation energy. Our calculations reveal the crucial role of CuI in the reaction and agree well with experimental findings.

Recent Advances in the Synthesis of Selenophenes and Their Derivatives

“…Selenophene derivatives have also been used as ligands in coordination chemistry [91][92][93][94][95][96][97]. After a pre-activation with a halide or an organometallic (B, Li, Mg, Sn or Zn), these compounds can be employed as reagents in the formation of new C-C [98][99][100][101][102][103][104][105][106][107], C-N [108][109][110] and C-S [111] bonds under Pd or Cu catalysis, through Heck, Stille, Negish, Kumada, Suzuki and Sonogashira coupling reactions. In recent years, unactivated selenophenes have been used as reagents in several synthetic transformations by palladium-catalyzed direct C-H bond activation [112][113][114][115][116].…”