Triphenylphosphine-<i>m</i>-sulfonate/Carbon Tetrabromide as an Efficient and Easily Recoverable Catalyst System for Friedel–Crafts Alkylation of Indoles with Carbonyl Compounds or Acetals

Abstract

A solid complex, conveniently prepared from commercially available sodium triphenylphosphine-m-sulfonate (TPPMS) and carbon tetrabromide, can be used as an easily recoverable and reusable catalyst system for Friedel–Crafts alkylation of indoles with carbonyl compounds or acetals to produce bis(indolyl)alkane products (BIAs).