“This article is a tutorial review which highlights some representative achievements on the subject and provides non-specialists, researchers, and graduate students a detailed summary of the overall concepts and principles of organic reactions in water.”

The two primary reasons for the paper’s being highly cited are the enormous interest worldwide in green chemistry and sustainable development as well as the vast increase in the number of papers on the subject of developing novel organic reactions through the use of water as solvent.

This article is a tutorial review which highlights some representative achievements on the subject and provides non-specialists, researchers, and graduate students a detailed summary of the overall concepts and principles of organic reactions in water.

In nature, nearly all organic reactions occur in the presence of water—or under aqueous conditions. Modern organic chemistry has been more or less developed with the notion that organic chemistry should take place in organic solvents unless water is used as a reagent.

It is only recently that scientists realized that the most abundant solvent on earth, water, is also an excellent solvent for many chemical reactions. In many cases, such reactions are superior to the ones in traditional organic solvents. However, by and large, the field is still considered to be highly specialized. This tutorial review provides an in-depth outline of the scope and significance of the field to non-specialists.

Great achievements have been made by many scientists in the field. In the early 1980s, Prof. R. Breslow and others reported on the unusual acceleration of Diels-Alder and other Pericyclic reactions in water—D. Rideout, R. Breslow, "Hydrophobic acceleration of Diels-Alder reactions," J. Am. Chem. Soc., 102: 7816, 1980.

In the late 1980s, while a graduate student—with T. H. Chan and D. N. Harpp—at McGill University, I became interested in organic reactions in aqueous media with the goal of simplifying the process of organic syntheses. During this time, Prof. Chan and I pioneered the well known indium-mediated allylation reaction in water.

After becoming a professor, my laboratory pioneered many metal-mediated and catalyzed Grignard-type carbon-carbon bond formation reactions in water. These reactions can fundamentally simplify organic synthesis by avoiding many protection-deprotection steps, in addition to replacing organic solvents.

There are other valuable contributions by many scientists worldwide covering the entire spectrum of organic chemistry. For example, the concept of organic reactions "on water" by Prof. K. Barry Sharpless of the Skaggs Institute of Chemical Biology has gained considerable attention.

As the field is often contradictory when compared to most things which we had previously known, there are enormous frustrations to be found within our own research. In the end, serendipity prevails.

Chemistry and chemical manufacturing provide the most materials needed for our modern society. However, the state-of-the-art ways of making chemical and materials products are highly inefficient and wasteful, both in terms of natural resources and energy. These wasteful methods cause additional health, environmental, and societal concerns.

New processes are urgently needed to drastically increase the efficiency of material and chemical productions to help us achieve a more sustainable society. Using water as solvent rather than large amounts of organic solvents for chemical production is one of the many related research endeavors.