Cu-facilitated C-O bond formation using N-hydroxyphthalimide: efficient and selective functionalization of benzyl and allylic C-H bonds.

A highly efficient protocol for the benzyl or allylic C-H functionalization of simple hydrocarbons has been developed using stoichiometric amounts of N-hydroxyphthalimide and PhI(OAc)2 in the presence of CuCl catalyst. The reaction was revealed to proceed via a radical pathway, in which phthalimide N-oxyl (PINO) radical plays a dual role, serving as a catalytic hydrogen abstractor from hydrocarbons as well as a stoichiometric reagent to couple with the resultant alkyl radicals.