Highly regioselective vinylogous aldol additions of silyl dienol ethers derived from simple α,β-unsaturated ketones are described. The catalyst system of silicon tetrachloride activated by chiral bisphosphoramide (R,R)-1 effectively promotes the addition of both γ-substituted and unsubstituted silyl dienol ethers to a variety of aldehydes with exclusive γ-regioselectivity and good to excellent diastereo- and enantioselectivity.
Lewis base - asymmetric catalysis - vinylogous aldol reactions - ketones - regioselectivity