Oxidant-Controlled C-sp²/sp³–H Cross-Dehydrogenative Coupling of N-Heterocycles with Benzylamines

Abstract

Oxidant controlled ionic liquid mediated cross-dehydrogenative coupling (CDC) of benzylamines with N-heterocycles having sp 2 or sp 3 carbon resulted in the formation of C-benzoylated or alkenylated products. Benzoylation of N-heterocycles occurs via (NH 4 ) 2 S 2 O 8 catalyzed benzoyl radical formation. An oxidative alkenylation of N-heterocycles having C-sp 3 carbon (2-methylaza-arenes) occurs via deamination of benzylamine followed by C-sp 3 -H bond activation in high stereoselectivity. Both benzoylation and alkenylation protocols are metal-free, green, simple, efficient, and tolerate a wide variety of functional groups.