The Utilization of Microwave Irradiation in Organic Synthesis: Organotrifluoroborate and Alumina Chemistry

The utilization of microwave irradiation in chemistry started in the 1950’s. Due to operational difficulties, organic chemists only began using microwaves in the mid- 1980’s, when better instruments were invented. This work describe the utilization of microwaves in two areas of organic chemistry: microwave enhanced reactions using organotrifluoroborates and microwave irradiation reactions catalyzed by highly acidic alumina.

In part one, a basic understanding of microwave irradiation is presented followed by the exploration of three major reactions. The first comprises the coupling of allyl acetate and cinnamyl acetate with various substituted potassium arylvinyltrifluoroborates to produce a variety of 1,4-dienes. The second explores the effects of microwave irradiation on the synthesis of stilbenes which led to new and efficient methods to prepare a variety of substituted stilbenes. The third study explores an efficient synthetic method for the allylation of various substituted potassium alkenyltrifluoroborates with allyl halides.

In part two, three major topics are discussed. The first involves the activation of alumina via microwave irradiation. The second involves the stereo- and regioselectivity of microwave enhanced Diels-Alder reactions. The third chapter describes the Claisen and Fries rearrangement reactions under microwave conditions.