Greener Approaches to Cross-Coupling - New Trends in Cross-Coupling: Theory and Applications - page 645

CHAPTER 14
Greener Approaches to
Cross-Coupling
KEVIN H. SHAUGHNESSY
Department of Chemistry, University of Alabama, Box 870336, Tuscaloosa,
AL 35487, USA
Email: [e-mail]
14.1 Introduction
As society has become more aware of the environmental impact of chemical
manufacturing, government regulation and public perception have caused
the chemical industry to lessen its impact on our surroundings. The initial
waves of environmental regulation focused on controlling chemical releases
and cleaning hazardous waste sites. In 1990, the United States passed the
Pollution Prevention Act, which changed the focus of environmental
regulation from release control to source reduction. This change in philo-
sophy caused chemists to consider how they design chemical processes to
minimize the waste produced and the hazards of the final products, rather
than focusing solely on how to deal with the hazardous materials produced.
The concept of green chemistry, which is guided by a set of principles
originally set out in 1998 by Anastas and Warner, 1 grew out of these efforts.
For the synthetic chemist, these principles provide a number of aspir-
ational goals to strive to meet in the design of new processes. Atom economy
should be maximized in reactions, while the use of unnecessary protection/
deprotection steps should be minimized. Side products that cannot be
avoided should be of limited toxicity. The use of solvents, which make up the
major mass in most chemical processes, should be minimized. Alternatively,