Microwave Frequency Effect(s) in Organic Chemistry

This brief article reviews the behavior of microwaves in organic syntheses from the viewpoint of the frequency effect, which has been examined on various common solvents with a newly fabricated 5.80-GHz microwave organic synthesis apparatus, whose features are compared with a similar 2.45-GHz microwave apparatus. Results from usage of the 5.80-GHz microwaves are also compared to the more frequently used MW frequency of 2.45 GHz. The frequency effect was examined for various organic reactions such as the Diels-Alder reaction, the synthesis of benzimidazole-based room-temperature ionic liquids, and the Suzuki-Miyaura coupling reaction. Non-polar solvents can prove particularly useful in organic reactions with the higher frequency microwaves. In this regard, further experiments on microwave-assisted organic syntheses will extend our understanding of the microwave frequency effect(s).