1-Acryloyl-2-cyanoindole: A Skeleton for Visible-Light-Induced Cascade Annulation.

1-Acryloyl-2-cyanoindoles were found to be novel and efficient skeletons in visible-light-induced persulfate-promoted cascade cyclization reactions. With this transition-metal-free photocatalytic procedure, various sulfonated/thiocyanated pyrrolo[1,2- a ]indolediones were synthesized from 1-acryloyl-2-cyanoindoles with sulfonyl hydrazides/NH 4 SCN at room temperature under mild reaction conditions.