Stereoselective synthesis of 1,3,4-substituted tetrahydro-β-carbolines from indoles based on selective transformations

Article abstract of DOI:10.1016/S0040-4020(97)00489-4

1, 3, 4-Substituted tetrahydro β-carbolines 4 have been prepared from indoles 6 by two selective transformations: first, nucleophilic aziridine ring opening with a lower order indolyl magnesium cuprate obtaining the α,β-substituted tryptamines 5 and secondly, a 'Pictet-Spengler-like' reaction between azalactones 12 and tryptamines 5. Under the acidic reaction conditions used, the thermodynamically favoured tetrahydro β-carbolines 4 are obtained due to the conformational restrictions imposed by the tryptamine substituents.