A single pot organocatalytic diastereoselective synthesis of fluorescent ring fused 2-pyridone decalines via a domino Knoevenagel/Michael/hydro-lactamisation sequence

Abstract

Multifunctional ring fused octahydro 3-CN-2-pyridone decaline motifs are constructed by a single pot multicomponent, diastereoselective, organocatalytic domino approach. Three consecutive catalytic reaction sequences are presented, wherein L-proline plays a catalytic dual role for Knoevenagel condensation and Michael addition co-operatively with PhCOOH, followed by annulation by hydro-lactamisation. Compounds containing bromine, chlorine, methoxy and methylenedioxy groups showed aggregation-induced fluorescence under long-range UV exposure. The present method is a green synthetic strategy with the following features: high diastereoselectivity (dr > 20), catalytic activity, high yields, cost-effective nature, a simple, mild, and operationally scalable process, and broad substrate scope.