The authors of this fourth volume in the series have reviewed the making and breaking of chemical bonds in a sophisticated manner. In particular, new pressures brought about by environmental concerns, larger demands for the medical and pharmaceutical sectors and economics of the market place are forcing us into demanding greater stereochemical control and better product yields for chemical reactions capable of producing useful products. The chapters are written by leading experts in this area and give excellent overviews of the strengths and weaknesses of the various methodologies. In Chapter 1 newer discoveries in such tried and true methods of C-C bond formation as alkylations and aldol reactions of metal enolates are reviewed. The author of Chapter 2 discusses the ability of ab-initio methods to justify the results of empirical observations in the field of transition metal derivatives of small molecules such as N2, CO2 and similar small molecules. Having established the strengths and weaknesses of the various approaches to such theoretical calculations, a more interesting approach to these methods is pursued, namely, their ability to predict, in those areas in which they are particularly strong and reliable, chemical and stereochemical events and/or results in advance of experiments, later carried out in the laboratory. Finally, Chapter 3 reviews the stereochemical results of electron transfer reactions in mononuclear copper compounds.