A new approach to the synthesis of functionalized pyrido[2,3-b]indoles by way of a palladium-catalyzed ring closing reaction between the N-1 and C- 9a positions

Article abstract of DOI:10.1016/S0040-4039(98)00065-3

The enolate of 4-N-(tert-butyloxycarbonyl)aminobutyro-γ-lactone 9 reacted with 2-bromo-1methylindole-3-carboxaldehyde in the presence of stannic chloride to give the product of aldol condensation 16. Deprotection and dehydration of the latter with trifluo