I2-DMSO-Promoted Direct Synthesis of Substituted Imidazoles from Styrenes and Benzylamines under Solvent-Free Conditions

A novel and efficient method has been developed for the direct synthesis of substituted imidazoles through the reaction of styrenes and benzylamines with the assistance of I2-DMSO concerted system. The reactions proceed efficiently under open air and solvent-free conditions to afford a wide variety of substituted imidazoles in good yields. A productive large-scale synthesis also has been performed to target highly substituted heterocyclic motifs. The present protocol offers metal- and solvent-free process, mild conditions, easily accessible reactants, and operational simplicity to achieve an assembly of substituted N-heterocyclic compounds.