Recent Advances in Microwave-Assisted Copper-Catalyzed Cross-Coupling Reactions

Cross-coupling reactions furnishing carbon-carbon (C-C) and carbon-heteroatom (C-X) bond is one of the most challenging tasks in organic syntheses. The early developed reaction protocols by Ullmann, Ullman-Goldberg, Cadiot-Chodkiewicz, Castro-Stephens, and Corey-House, utilizing elemental copper or its salts as catalyst have, for decades, attracted and inspired scientists. However, these reactions were suffering from the range of functional groups tolerated as well as severely restricted by the harsh reaction conditions often required high temperatures (150-200 degrees C) for extended reaction time. Enormous efforts have been paid to develop and achieve more sustainable reaction conditions by applying the microwave irradiation. The use of controlled microwave heating dramatically reduces the time required and therefore resulting in increase in the yield as well as the efficiency of the reaction. This review is mainly focuses on the recent advances and applications of copper catalyzed cross-coupling generation of carbon-carbon and carbon-heteroatom bond under microwave technology.