Metal-free one-pot synthesis of 2-substituted benzimidazoles from N-aryl imines and TMSN3

Iodine-catalysed efficient synthesis of 2-substituted benzimidazoles has been developed under aerobic condition. The one-pot oxidative cascade reactions of anilines, aldehydes and trimethylsilyl azide (TMSN3) lead to the benzimidazoles derivatives in the presence of tert-butyl hydroperoxide (TBHP). Iodine efficiently promoted the cross-coupling strategy to achieve the desired compounds via the sequential CH functionalization and cyclization. The present method features a greener approach, readily accessible reagents, broad substrate scope, high yields of the products, shorter reaction time and mild conditions.