CSIRO PUBLISHING - Australian Journal of Chemistry

Invited Review. A Combinatorial Approach to the Development of Environmentally Benign Organic Chemical Preparations

Christopher R. Strauss

Abstract

Enabling technologies and methodologies were established and combined to afford various environmentally benign processes for laboratory-scale organic synthesis and for the production of fine chemicals, intermediates and pharmaceuticals. The technologies comprised continuous and batch microwave reactors and catalytic membranes. The methodologies included solvent-free conditions, catalysed or uncatalysed processes, the use of aqueous media at high temperature and non-extractive techniques for product isolation. Applications included Hofmann eliminations, Willgerodt and Jacobs–Gould reactions, indole transformations, aldol condensation, Rupe and Meyer–Schuster rearrangements and C–C coupling reactions (including a tandem Heck coupling–dehydrogenation). New processes for catalytic etherification, uncatalysed hydrogen transfer and a one-step arylamidation were also developed. Typical products were N-(4-hydroxyphenyl)acetamide, carvacrol, a-phenylacetamide, cinnamaldehyde, cinnamyl alcohol, acetophenone, indole, 3-hydroxy-1,2-dimethyl-4-pyridone, di(2-phenylethyl) ether, di(cyclopropylmethyl) ether, 3-methylcyclopent-2-enone and a synthetic precursor of nalidixic acid.