Transition-Metal-Free Transfer Hydrogenative Cascade Reaction of Nitroarenes with Amines/Alcohols: Redox-Economical Access to Benzimidazoles

Kabi, Arup K.; Gujjarappa, Raghuram; Roy, Anupam; Sahoo, Abhishek; Musib, Dulal; Vodnala, Nagaraju; Singh, Virender; Malakar, Chandi C.

Transition-Metal-Free Transfer Hydrogenative Cascade Reaction of Nitroarenes with Amines/Alcohols: Redox-Economical Access to Benzimidazoles

Date

2021-10-19T00:00:00

Authors

Publisher

American Chemical Society

Abstract

This report describes an efficient transition-metal-free process toward the transfer hydrogenative cascade reaction between nitroarenes and amines or alcohols. The developed redox-economical approach was realized using a combination of KOtBu and Et3SiH as reagents, which allows the synthesis of benzimidazole derivatives via ?-bond metathesis. The reaction conditions hold well over a wide range of substrates embedded with diverse functional groups to deliver the desired products in good to excellent yields. The mechanistic proposal has been depicted on the basis of a series of control experiments, mass spectroscopic evidence which is well supported by density functional theory (DFT) calculations with a feasible energy profile. � 2021 American Chemical Society.

Keywords

Amines, Density functional theory, Benzimidazole derivatives, Benzimidazoles, Cascade reactions, Control experiments, Mechanistics, Metal free, Nitroarenes, Reaction conditions, Spectroscopic evidence, ?-bond metathesis, Transition metals