An inverse electron-demand diene-transmissive hetero-Diels–Alder reaction of N-sulfonyl-[3]-1-azadendralenes for stereocontrolled synthesis of polyhydroquinolines
Cross-conjugated 1-azatrienes ([3]-1-azadendralenes) bearing a sulfonyl group on the nitrogen atom were converted to various polyhydroquinolines with multiple stereocentres via a diene-transmissive hetero-Diels-Alder (DA) reaction consisting of an inverse electron-demand aza-DA reaction with electron-rich dienophiles followed by a stereoselective DA reaction with electron-deficient dienophiles. (C) 2015 Published by Elsevier Ltd.
Phosphine-Catalyzed (3 + 2) Annulation of γ-Substituted Cinnamic Aldehyde-Derived Morita–Baylis–Hillman Carbonates through Remote Activation