Since the discovery of significant rate enhancement of microwave irradiation in organic chemical transformations by the Gedye and Giguere/Majetich groups in 1986,1 microwave heating has become a fast-moving and exciting field in synthetic community.2 Spectacular accelerations, high yields, and good selectivity (chemo-, regio-and stereoselecitivty) under milder conditions have often been described using microwave compared to conventional heating.3 The effect of microwave irradiation is a combination of thermal effects, arising from the volumetric heating nature, superheating and the selective absorption of radiation by polar substances. On the other hand, the non-thermal effect of highly polarizing radiation, which is still a controversial topic, provides additional benefits for microwave as an impressive applicable new energy source.4 However, it was found that hot spots, thermal runaway and explosions were often produced during the microwave assisted on heterogeneous reactions.5 In addition, due to high pressure generated from heated gas, conducting gas/liquid heterogeneous reactions in microwave is difficult in Xpractical.
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