Direct asymmetric aldol addition-isomerization of α,β-unsaturated γ-butyrolactam with aryl α-ketoesters: synthesis of MBH-type products

A highly efficient direct asymmetric aldol addition-isomerization reaction at the alpha-position of alpha,beta-unsaturated gamma-butyrolactam and aryl alpha-ketoesters by using a bifunctional thiourea catalyst was achieved. Morita-Baylis-Hillman type adducts containing a quaternary stereocenter can be obtained in high yields and with excellent enantioselectivities (up to 99% ee).