Visible-light photocatalysed synthesis of coumarin derivatives

A straightforward, environmentally friendly, and highly efficient, metal-free, visible light mediated organophotocatalysed method has been devised for synthesizing potentially biologically active substituted coumarin scaffolds. This method involves the reaction between substituted ethynylbenzene and substituted phenyl formate under visible light photoredox catalysed conditions at room temperature using acridinium as photocatalyst. The distinctive characteristics of the current methodology include mild reaction conditions, yielding good to excellent outcomes, promoting high atom-economy, environmentally friendly practices, clean reaction profiles, and suitability for large-scale synthesis.