ABSTRACT
This chapter starts with simplest and most familiar concept of organic reactions in water. It focuses on the on-water reactions. The chapter addresses the innovative aspect of organic reactions in water that occur between water-insoluble organic compounds. It describes the hydrophobic effects, which enable reactions of water-insoluble reactants to occur in water. The chapter introduces a common nomenclature for the hydrophobic effects and the associated phenomena. It focuses on two examples of the on-water reactions, which are well known, and have extensive applications. They are the Diels-Alder and Passerine reactions. The chapter offers a sampler of other on-water reactions to illustrate the breadth and scope of this class of reactions. The Diels-Alder reaction is one of the more important carbon-carbon bond-forming reaction classes. This reaction occurs between a Diane and a dienophile. The inverse temperature dependence of the Passerine reaction has mostly favorable consequences for green chemistry.
