Stereocontrolled synthesis of heterocycles from unactivated alkynes by photoredox/nickel dual-catalyzed cyclization†

Abstract

We introduce an innovative nickel/photoredox dual catalytic sulfonyl-arylation method for synthesizing heterocyclic compounds directly from unactivated alkynes and aryl iodides. This green chemistry approach sidesteps traditional Heck reactions, eliminating reliance on excess metal catalysts and reagents. The method ensures high chemical selectivity, curbing side reactions and facilitating the stereoselective 6-exo-dig cyclization. It simplifies the production of nitrogen- or oxygen-containing heterocyclics, such as 3,4-dihydroisoquinolin-1(2H)-ones, tetrahydroisoquinolines, and isochroman derivatives, with potential applications in medicinal chemistry. The dual catalytic system enhances reactivity with unactivated substrates, marking a significant step in synthetic chemistry.