InBr3-catalyzed intramolecular cyclization of 2-alkynylanilines leading to polysubstituted indole and its application to one-pot synthesis of an amino acid precursor

We describe InBr3-catalyzed cyclization of 2-alkynylanifine derivatives having a variety of functional groups producing polysubstituted indoles. This methodology could be applied to the one-pot synthesis of an amino acid precursor by the addition of a catalytic amount of the indium salt, an imine, and TMSCI. (c) 2005 Elsevier Ltd. All rights reserved.