Organoseleno-Catalyzed Synthesis of α,β-Unsaturated α′-Alkoxy Ketones from Allenes Enabled by Se···O Interactions

α,β-Unsaturated α′-alkoxy ketones have been prepared under mild conditions from allenes using water as the oxygen source and without the necessity of metals. The organocatalytic oxygenation–rearrangement sequence displays an exquisite chemo-, stereo-, and site-selectivity as well as good functional group compatibility. DFT calculations suggest that stabilizing noncovalent Se···O interactions may be responsible for the observed reactivity.