A general solution to implementing the 4.pi. participation of 1-aza-1,3-butadienes in Diels-Alder reactions: inverse electron demand Diels-Alder reactions of .alpha..beta.-unsaturated N-benzenesulfonyl imines
Significant improvement in enantioselectivity and catalyst activity was achieved for the catalytic enantio selective Strecker reaction. Using a catalyst (1-2.5 mol%) prepared from Gd((OPr)-Pr-i)(3) and D-glucose derived ligand 1, and in the presence of 2,6-dimethylphenol as an additive, high enantioselectivity was obtained from a wide range of ketoimines, including heteroaromatic and cyclic ketoimines. The new method was applied to an efficient catalytic asymmetric synthesis of sorbinil, a therapeutic agent for diabetic complications. (C) 2004 Elsevier Ltd. All rights reserved.
A general solution to implementing the 4.pi. participation of 1-aza-1,3-butadienes in Diels-Alder reactions: inverse electron demand Diels-Alder reactions of .alpha..beta.-unsaturated N-benzenesulfonyl imines