Ketonitrones via Cope-type hydroamination of allenes.

The synthesis of ketonitrones from N-alkylhydroxylamines and monosubstituted allenes is accomplished via a Cope-type hydroamination reaction in moderate to good yields. Allenes also undergo a similar reaction with aqueous hydroxylamine to give oximes in excellent yield. DFT calculations support a proposed concerted, five-membered hydroamination process, and calculated transition state energies are in excellent agreement with experimental observations.