Stereoselective Synthesis of Biheterocycles Containing Indole and 5,6-Dihydropyridin-2(1H)-one or α-Methylene-β-butyrolactam Scaffolds

摘要

Indium-mediated allylation of N-tert-butanesulfinyl imines derived from indole-2 and 3-carbaldehydes 3 and 5 with allylic bromides 6,proceed with high diastereoselectivity.Homoallylic amide derivatives 13 and 14 are transformed into dihydropyridinones 15 and 16,upon successive desulfinylation,Nacylation with acryloyl chloride and ring-closing-metathesis.Desulfinylation of amine ester derivatives 17 and 18,obtained when ethyl 2-(bromomethyl)acrylate(6b)is used as the allylating reagent,lead to the corresponding α-methylene-γ-butyrolactams 19 and 20,in modest yields.