ABSTRACT
Introduction Phase-transfer catalysis (PTC) is an important tool in the organic chemist’s armory to conduct reactions involving two mutually insoluble solvents. Chemical engineers were almost completely unconcerned with PTC till around mid-1970s. Then, after a period of lukewarm interest for over a decade (when some basic advances were made), it gained a respectable position in the 1980s and has since been experiencing a steady growth. This period (starting from around 1970) also roughly coincided with CRE becoming more inclusive in that large-volume chemicals were no longer its single main focus, such as the petroleum rening, petrochemical, and heavy organic and inorganic chemical industries. Areas of general interest in small-and medium-volume chemicals, such as pharmaceutical engineering and PTC, moved increasingly from technology to engineering science orientation.
