Organic Reactions of Anions

This chapter presents computational studies of organic reactions that involve anions. It also presents the contributions of computational chemistry toward understanding the mechanism and chemistry for three reactions involving nucleophilic attack. The SN2 reaction, with emphasis on the gas versus solution phase, is presented first. Nucleophilic substitution reactions are among the first synthetic transformations introduced to beginners learning organic chemistry. The mechanisms for these reactions-SN1 and SN2-provide the paradigm for mechanistic understanding of organic reactions. The chapter describes the critical contribution that computational chemists made in developing the theory of asymmetric induction at carbonyl and vinyl compounds. It concludes with a discussion on the collaborative efforts of synthetic and computational chemists in developing organic catalysts, especially proline and proline-related molecules, for the aldol, Mannich and Michael reaction, and other related reactions.