Phase Transfer Catalysis: A Tool for Environmentally Benign Synthesis

Phase transfer catalysis (PTC) is a long known contributor to sustainable synthesis. The generic method underwent many improvements over the past decades, and several new technical advances were made. This chapter summarizes the recent developments in this field. One of the major areas of application is in asymmetric synthesis by chiral phase transfer catalysts, including modified natural products (e.g., cinchona alkaloids) and synthetic alternatives, such as 1,1'-bi-2-naphthol (BINOL)-based catalysts. The second part of the work deals with new areas including polymer-bound phase transfer catalysts that extend PTC to three-phase systems and multisite catalysts that effectively catalyze several reactions and improve the likelihood of catalyst recycling.