Catalyst-Controlled C–O versus C–N Allylic Functionalization of Terminal Olefins

The divergent synthesis of syn-1,2-aminoalcohol or syn-1,2-diamine precursors from a common terminal olefin has been accomplished using a combination of palladium(II) catalysis with Lewis acid cocatalysis. Palladium(II)/bis-sulfoxide catalysis with a silver triflate cocatalyst leads for the first time to anti-2-aminooxazolines (C–O) in good to excellent yields. Simple removal of the bis-sulfoxide ligand from this reaction results in a complete switch in reactivity to afford anti-imidazolidinone products (C–N) in good yields and excellent diastereoselectivities. Mechanistic studies suggest the divergent C–O versus C–N reactivity from a common ambident nucleophile arises due to a switch in mechanism from allylic C–H cleavage/functionalization to olefin isomerization/oxidative amination.