Merging 2,3-butanedione and N-hydroxysuccinimide as visible-light-enabled hydrogen atom transfer catalysts for CC double bond cleavage of 2-cyanoaryl acrylamides toward the synthesis of 4-amino-2-quinolones†

Abstract

The CC double bond cleavage of 2-cyanoaryl acrylamides through merging 2,3-butanedione and N-hydroxysuccinimide as visible-light-enabled hydrogen atom transfer catalysts is effectively established for generating functionalized 4-amino-2-quinolones under metal-free and redox neutral conditions. Detailed mechanism studies indicate that the solvent 1,3-dioxolane offers the crucial 1,3-dioxolan-2-yl radical facilitated by the in situ formed H-atom abstracting species, and 2-alkenyl-1,3-dioxolane is probably another product in this photocatalytic protocol.