Bis-NHC-based Manganese(I) complex catalyzed amide and CO2 hydroboration

Abstract

The reductive modification of the C=O moiety in cyclic/acyclic amides, and even involving carbon dioxide, determines a formidable challenge but holds crucial significance for synthesizing value-added chemicals. This process harbors the potential to unveil new avenues for utilizing non-fossil feedstocks. Earth-abundant, environment-friendly, and cost-effective metal catalysts could play a crucial role in driving the advancement of sustainable synthetic processes grounded on this principle. Manganese bis-(NHC) complexes' activity in the reducing challenging carbonyl (C=O) group and carbon dioxide (CO2) has been attributed to the strong σ-donating and weak π-accepting properties of the bis-(NHC) carbene. Herein, we have employed the bis-NHC-based manganese complexes as effective catalysts for the hydroboration of both primary and secondary amides, which are quite difficult to reduce due to better resonance within the amide system and obtained moderate to excellent yield. Additionally, we employed these complexes to reduce carbon dioxide (CO2) under solvent-free conditions, yielding moderate yields.