Enantioselective Diels-Alder reactions of enals: Fighting species multiplicity of the catalyst with donor solvents

Article abstract of DOI:10.1016/S0957-4166(00)86117-0

Chiral Lewis acids obtained from reactions of N-arylsulphonylamino acids with borane adducts effectively catalyze Diels-Alder additions of α,β-unsaturated aldehydes. Maximum enantioselectivity (methacrylaldehyde: 86 %ee, crotonaldehyde: 81 %ee) was achieved in donor solvents. The first results with new chiral Lewis acids derived from C₂-symmetric N-sulphonyl derivatives of 2,2'-diamino-1,1'-binaphthyl are also presented.