Single step, solvent-free processes: examples and prospects

An outline is given of some of the options now available - and likely to be of growing importance - for various of ways in which inorganic catalysts may be developed to effect industrially important chemical reactions in environmentally more acceptable means. One major goal is to devise ways of producing in situ (within the sphere of reaction) aggressive oxidants especially those that are environmentally hazardous. Two specific examples are cited: 1) one involves hydroxylamine, generated in a benign fashion, so as to effect the ammoximation of cyclohexanone to its oxime and e-caprolactam; 2) the other involves the Baeyer-Villiger reaction (for converting cyclic ketones to lactones) via perbenzoic acid. The role of supported bimetallic catalysts in solvent-free hydrogenations (especially of polyenes) is also highlighted.