Zn(Proline)2: a novel catalyst for the synthesis of dicoumarols

摘要

A novel, greener approach was adopted for the synthesis of dicoumarols (3a-j) using Zn(Proline)2 as a mild, non-toxic, Lewis acid catalyst in water employing 4-hydroxycoumarin (1) and aromatic/heteroaromatic aldehydes (2a-j). The catalytic activity results suggest that the methodology adopted offers several advantages such as mild reaction conditions, low loading of catalyst, quantitative yields, short reaction time and operational simplicity.