Gallou, Fabrice (2021) Water in organic chemistry:from our worst enemy to our best friend. Chemical science, 12. pp. 4237-4266.

Abstract

Although water is Nature’s solvent, it has long been regarded by organic chemists, at least until recently,
as their worst enemy. From introductory organic chemistry courses to multi-kilo labs of contract
manufacturing organizations (CMOs), chemists are taught that the presence of water in most organic
reactions should be avoided at all cost. Historically, the paradigm that “like dissolves like”, implying that
dissolution is a prerequisite for high conversion, led to the obvious conclusion that water is a “no-go.” This
notion may have arisen from the observation that for some catalysts, reagents, and/or reaction conditions,
there is a definite element of moisture-sensitivity. Thus, organic solvents, and when necessary, very dry
organic solvents, have always been the norm, with most subsequent developments made with this in mind.
However, toxicity issues such as mutagenicity, teratogenicity, carcinogenicity, and/or reprotoxicity can be
ascribed to many of these same solvents. The risk to operators in the plant due to flammability, explosivity,
and exposure, in general, is not trivial, whether arising from their industrial applications, transportation, or
storage. Their impact on the environment must not be overlooked either. Volatile organic compounds
(VOCs) can contribute to smog, air pollution, ground-level ozone production and yes, climate change. The
persistence of chlorinated solvents in soils and aquatic environments represents yet another non-negligible
environmental threat.1 For these reasons, regulations are becoming increasingly severe regarding
production and use of organic solvents, forcing chemists to find greener and safer alternatives. While the
Montreal Protocol2 aims to control usage of nearly 100 man-made ozone-depleting substances since 1987,
the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH)3 regulation has been
more recently adopted in Europe, looking to protect both human health and the environment from the risks
posed by chemicals.

Item Type:	Article
Date Deposited:	18 May 2021 00:45
Last Modified:	18 May 2021 00:45
URI:	https://oak.novartis.com/id/eprint/43649