Dual Organocatalysis: Asymmetric Allylic-Allylic Alkylation of α,α-Dicyanoalkenes and Morita-Baylis-Hillman Carbonates

The unprecedented asymmetric allylic-allylic alkylation of α,α-dicyanoalkenes and Morita-Baylis-Hillman (MBH) carbonates were developed by catalyzing by a suitable chiral tertiary amine. The resulting multifunctional alkylation products could also serve as versatile intermediates for other synthetic transformations. The analogous catalysts show no catalytic activity in the model reaction due to steric activity. The alkylation reaction could be conducted at higher temperature in 1,2-dichloroethane (DCE) with little effect on the enantioselectivity. Excellent results are obtained by employing two equivalents of the MBH adduct and when 10% mol of (R)-BINOL is used. Mixtures of mono and double-allylic alkylation products are formed when symmetric α,α-dicyanoalkenes are applied. It is also found that the double-allylic alkylation adducts with four stereogenic centers could be isolated as single diasteromers with remarkable ee values.