2-Methyl-2-(pyridin-2-yl)malononitrile: a site-selective cyano transfer reagent for photocatalytic cyanation reactions

Abstract

Herein, we report the development of a carbon-bound radical cyanating reagent, 2-methyl-2-(pyridin-2-yl)malononitrile (MPYMN), which enables metal-free photocatalytic cyanation with high reactivity and site selectivity. MPYMN is a bench-stable, readily accessible solid that does not release cyanide during reactions nor does it require metals or harsh conditions. It exhibits superior performance compared to commercially available cyanating agents and other carbon-bound cyanide sources. Importantly, the steric effect of the quaternary carbon in MPYMN facilitates reagent-controlled site-selective cyanation. The synthetic utility of this reagent is demonstrated by its compatibility with both photoredox and hydrogen atom transfer (HAT) processes, including efficient late-stage functionalization of complex molecules relevant to medicinal chemistry.