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

A Sc(OTf)3-catalyzed N–O group transfer reaction through C═N bond cleavage of N-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-endo-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 N-vinyl nitrones.