CuI/I2-Promoted Electrophilic Tandem Cyclization of 2-Ethynylbenzaldehydes with ortho-Benzenediamines: Synthesis of Iodoisoquinoline-Fused Benzimidazoles

An efficient tandem route to the synthesis of iodoisoquinoline-fused benzimidazole derivatives including an iodocyclization strategy has been developed. In the presence of CuI, a variety of 2-ethynylbenzaldehydes underwent the tandem reaction with benzenediamines and iodine to afford the corresponding iodoisoquinoline-fused benzimidazoles in moderate to good yields.