Several alternative strategies for non-green polar aprotic solvents

Abstract

Polar aprotic solvents are widely used in the organic synthesis and pharmaceutical research, while most of them are not green because their detrimental effects to human health and their hazards to natural environment cause lots of negative effects due to their mass production and consumption. Therefore, minimizing and avoiding the use of such solvents has become one of important facets of green chemistry. Until now, substantial efforts have been devoted and lots of researches have been reported in response to this problem. In the context, this review summarizes the methods and strategies for replacing non-green polar aprotic solvents, which mainly includes the direct replacement with new green alternatives and the utilization of polarized catalysts for avoiding the use of conventional polar aprotic solvents. Besides, their strengths and weaknesses were analyzed for both of the two strategies. Compared with the direct replacement strategy, the design of polarized catalysts not only expands the choice of green solvents, but also provides new possibilities for the design and preparation of multifunctional catalysts, suggesting a promising prospect in substitution strategies for non-green polar aprotic solvents.