Photo-mediated Intermolecular Coupling of Alkenes with Ketones via Acyloxy Nitroso Compounds.

Abstract

Visible light mediated atom economic intermolecular radical addition reaction of acyloxy nitroso compounds to electron-deficient alkenes is reported. The starting nitroso derivatives are readily prepared upon oxidation of the corresponding oximes prepared from ketones and the overall transformation represents an oxidative coupling of a ketone with a Michael acceptor. The cascade proceeds smoothly under mild conditions, providing a series of valuable functionalized oximes in moderate to good yields. Mechanistic studies suggest that these cascades proceed via addition/coupling processes that are controlled by the persistent radical effect (PRE) with NO acting as the persistent species.