New catalytic asymmetric Lewis acids have been developed for the aza- Diels-Alder reaction of a methyl glyoxalate and p-anisidine derived imine with Danishefsky's diene. The catalysts were developed using parallel combinatorial methods, with the highest e.e. being 97% using (1S, 2S)-1,2- diphenylethylenediamine and magnesium iodide in acetonitrile.
Bromidge, S., Wilson, P. C., & Whiting, A. (1998). A parallel combinatorial approach to locating homochiral Lewis acid catalysts for the asymmetric aza-Diels-Alder reaction of an imino dienophile. Tetrahedron Letters, 39(48), 8905–8908. https://doi.org/10.1016/S0040-4039(98)01947-9