Microwave Technology—Applications in Chemical Synthesis

TLDR: In this article, the authors reviewed microwave heating for expeditious chemical syntheses and showed that solvent-free reactions or reactions in benign media are convenient to perform and have advantages over the conventional heating protocols.

Abstract: Microwave heating, a unique heating technique is reviewed for expeditious chemical syntheses. Specifically, the solvent-free reactions or reactions in benign media are convenient to perform and have advantages over the conventional heating protocols as summarized in the previous editions. A wide range of selective functional group transformations have been accomplished expeditiously and efficiently using a variety of supported reagents on mineral oxides as catalysts or in benign reaction media. Further scale-up developments on such themes will go a long way in realizing the sustainable goals in the chemical arena including the synthesis of nanomaterials and nano-catalysts. The major limitations for MW-assisted reactions can be overcome by translating batch microwave chemistry to continuous flow domain wherein conventionally heated and suitably equipped fluidic flow devices may help produce meaningful amounts of chemical products in a continuous mode. This is especially true for the use of magnetic nano catalysis in flow chemistry which has a great potential to grow in this sustainable endeavor as the nanoparticle-bound magnetic catalysts can be confined and at the same time agitated in a reactor by a rotating magnetic field, thus, avoiding potential problems of clogging membranes or filters that are commonly used as barriers for immobilized catalysts. Keywords: Microwave Irradiation; Solvent-free reactions; Aqueous Chemistry; Nano-catalysts