2-Azetidinones: synthesis of new bis(indolyl)butyl-β-lactams

Abstract

New β-lactam compounds containing a bis(indolyl)-framework were synthesized. The key step in the synthetic strategy was a nucleophilic addition of unprotected indole to a suitable butyl aldehyde anchored on the C-4 side chain of azetidinone intermediates. The use of an ionic liquid as reaction medium allowed the use of a catalytic amount of Dy(OTf)₃ for the nucleophilic addition and facilitated the isolation of the product.