Photocatalytic vinyl radical-mediated multicomponent 1,4-/1,8-carboimination across alkynes and olefins/(hetero)arenes

Abstract

We developed a highly selective and efficient multicomponent transformation by utilizing alkynes and olefins/(hetero)arenes through photoinduced energy-transfer catalysis. The reaction involves the formation of three distinct chemical bonds, namely C(sp³)–C(sp²), C(sp²)–C(sp³), and C(sp³)–N, in a single coordinated manner. The strategy used a vinyl radical-mediated radical relay approach under mild conditions, exhibiting a broad substrate scope (>70 examples), excellent functional-group tolerance, and remarkable regio- and anti-stereoselectivity. Through the utilization of a combination of experimental techniques and density functional theory (DFT), we delved deeper into the mechanistic intricacies of this distinctive system. Results revealed that the selective radical addition to electron-deficient alkynes, rather than olefins, was governed by the inherent reactivity of alkyl radicals. This discovery presented a highly effective approach for the synthesis of stereodefined multisubstituted alkenes.