Radical-mediated intramolecular β-C(sp)-H amidation of alkylimidates: facile synthesis of 1,2-amino alcohols.

A new radical-mediated intramolecular β-C(sp)-H amidation reaction of O-alkyl trichloro- or arylimidates is reported. Various oxazolines were efficiently prepared from easily accessible alcohol starting materials. The trichloro-oxazoline products can be hydrolyzed under mild conditions to give valuable 1,2-amino alcohols. This amidation reaction exhibits a broad substrate scope and good functional group tolerance, and offers a powerful means for the C(sp)-H functionalization of alcohols. Mechanistic studies suggest that a sequence of 1,5-HAT of an imidate radical, iodination and cyclization might be operative.