Synthesis of β-Aminooxy Ketones through Sc(OTf) ₃ -Catalyzed C═N Cleavage and N–O Group Transfer Reaction of <i>N</i> -Vinyl Nitrones

A Sc(OTf)₃-catalyzed N-O group transfer reaction through C═N bond cleavage of <i>N</i>-vinyl-α,β-unsaturated nitrones has been developed to prepare various β-aminooxy ketones in moderate to good yields ranging from 20% to 86% under mild reaction conditions. Mechanistic studies revealed that the reaction underwent intramolecular 5-<i>endo</i>-trig cyclization and C═N bond cleavage. The present method features a broad substrate scope, good functional group tolerance, selective C═N bond cleavage, and the first N-O group transfer reaction of <i>N</i>-vinyl nitrones.