Abstract
The Suzuki cross-coupling reaction is one of the most used transformations in drug research. Propylene carbonate is a sustainable green solvent in cross-coupling reactions with high yields. The solvent is safe and environmentally benign because its production involves the fixation of atmospheric carbon dioxide. Reducing the greenhouse effect by removing harmful carbon dioxide from the air contributes to the deceleration of global warming. Propylene carbonate is a less toxic, less flammable, and less explosive solvent than the traditionally used tetrahydrofuran, 1,4-dioxane or benzene. Because of its high boiling point, there are numerous possibilities to use propylene carbonate in reactions: conventional heating in round-bottom flasks, microwave reactors, flow reactors, etc. Nevertheless, propylene carbonate is not stable enough and undergoes partial ring opening in the presence of a base in the reaction mixture. This examination addresses not only the scope and limitation of propylene carbonate as a solvent, but also includes the comparison of microwave reactor conditions with conventional heating. Using microwave heating instead of conventional heating leads to better yields and shorter reactions. In a microwave reactor, there is also the possibility to increase the pressure. That is, microwaves facilitate reactions, which do not reach high conversions at atmospheric pressure, but may provide better results at higher pressure range.
