The asymmetric Bischler–Napieralski reaction: preparation of 1,3,4-trisubstituted 1,2,3,4-tetrahydroisoquinolines
Abstract
The Bischler–Napieralski reaction, which is used to prepare dihydroisoquinolines from phenylethylamides, is demonstrated by the reaction of (S)-1-alkyl-1,2-diphenylethylamides with POCl3–P2O5. The reaction generated 3-alkyl-4-phenyl-1,2-dihydroisoquinolines with stereochemical selectivities of 80–91% de depending on the