The base-free van Leusen reaction of cyclic imines on water: synthesis of N-fused imidazo 6,11-dihydro β-carboline derivatives

Abstract

Construction of imidazoles has been demonstrated on water under base-free conditions. The reaction of dihydro β-carboline imines and p-toluenesulfonylmethyl isocyanides furnished the corresponding substituted N-fused imidazo 6,11-dihydro β-carboline derivatives in very good yields under ambient conditions. The use of deuterium oxide (D₂O) as a solvent enabled the incorporation of deuterium isotopes in the imidazole ring.