Cobalt catalyzed condensation interrupted selective transfer hydrogenation using methanol

Abstract

Utilizing methanol transfer hydrogenation (TH) of nitroarene and α,β-unsaturated ketones has significant challenges as it mostly produced the corresponding N/C-methylated and over-hydrogenated products. Hence, selective synthesis of amines and saturated ketones from nitroarene and α,β-unsaturated ketones respectively employing methanol as hydrogen source is an exciting area of research. Additionally, development of air and moisture-stable reusable cobalt based catalytic system for the dehydrogenation of methanol is a fascinating area to investigate. In this prospect, we disclosed a single atom cobalt catalysed condensation interrupted selective TH of a library of various nitroarenes and α,β-unsaturated ketones using methanol as a hydrogen source. A series of pharmaceutically important drug molecules was synthesized to establish the synthetic applicability of this methodology. Several control experiments were carried out to understand the reaction mechanism. Notably, this catalyst was recycled up to six times without considerable loss of its catalytic activity.