Catalyst free -formylation of aromatic and aliphatic amines exploiting reductive formylation of CO using NaBH.

Herein, we report a sustainable approach for -formylation of aromatic as well as aliphatic amines using sodium borohydride and carbon dioxide gas. The developed approach is catalyst free, and does not need pressure or a specialized reaction assembly. The reductive formylation of CO with sodium borohydride generates formoxy borohydride species , as confirmed by H and B NMR spectroscopy. The formation of formoxy borohydride species is prominent in formamide based solvents and is critical for the success of the -formylation reactions. The formoxy borohydride is also found to promote transamidation reactions as a competitive pathway along with reductive functionalization of CO with amine leading to -formylation of amines.