Development of an Imine Chaperone for Selective C–H Functionalization of Alcohols via Radical Relay

The design of a radical
relay chaperone to promote selective C–H
functionalizations is described. A saccharin-based imine was found
to be uniquely suited to effect C–H amination of alcohols via
an in situ generated hemiaminal. This radical chaperone
facilitates the mild generation of an N-centered radical while also
directing its regioselective H atom transfer (HAT) to the β
carbon of an alcohol. Upon β C–H halogenation, aminocyclization,
and reductive cleavage, an NH2 is formally added vicinal
to an alcohol. The development, synthetic utility, and chemo-, regio-,
and stereoselectivity of this imine chaperone-mediated C–H
amination is presented herein.