Synthesis of alpha-pyrones and chromen-2-ones by transition-metal catalyzed annulations of sulfoxonium and iodonium ylides with cis-stilbene acids

Abstract

A transition metal-catalyzed carbene insertion strategy has been developed to activate the inactivated sp² C–H bond of medicinally important cis-stilbene acids. This approach enables the facile construction of α-pyrone and chromene-2-one skeletons on the olefinic bond of cis-stilbene acid with high atom economy, good yield, broad functional group tolerance and gram-scale synthetic feasibility. The strategy unveils the efficiency of acid functionalities as directing groups along with sulfoxonium and hypervalent iodonium ylide as carbene precursors. The constructed architectures were explored for their photophysical properties showing emission ranging from 500 to 600 nm, and the biological potential was examined through molecular docking analysis and percentage inhibition studies. Additionally, ESI-MS studies were also performed to identify the key intermediates, helping to sketch a probable mechanism.