Chromium-catalysed efficient N-formylation of amines with a recyclable polyoxometalate-supported green catalyst

A simple and efficient protocol for the formylation of amines with formic acid, catalyzed by a polyoxometalate-based chromium catalyst, is described. Notably, this method shows excellent activity and chemo-selectivity for the formylation of primary amines; diamines have also been successfully employed. Importantly, the chromium catalyst is potentially non-toxic, environmentally benign and safer than the widely used high valence chromium catalysts such as CrO3 and K2Cr2O7. The catalyst can be recycled several times with a negligible impact on activity. Finally, a plausible mechanism is provided based on the observation of intermediate and control experiments.

Automated summary

This research presents a simple and efficient protocol for the formylation of amines using a polyoxometalate-based chromium catalyst, demonstrating excellent activity and chemo-selectivity for primary amines and diamines. The chromium catalyst is potentially non-toxic, environmentally friendly, and safer than commonly used high valence chromium catalysts like CrO3 and K2Cr2O7, with the ability to be recycled multiple times without significant loss of activity. Additionally, a plausible mechanism is proposed based on intermediate observation and control experiments.