High-energy glycoconjugates: synthetic transformations of carbohydrates using microwave and ultrasonic energy.

Methods to transform carbohydrates are often complex and tedious, both due to the vast array of naturally occurring and synthetically designed scaffolds which may manifest meager to drastic reactivity, dependent upon the transformation sought and the stereogenic site chosen. In order to facilitate and expedite desired synthetic transformation, many researchers are utililizing microwave and ultrasonic irradiation to achieve their goals, in generally high yields within a shorter period of time, and often without undesirous byproducts. The basic physical principles underlying the energy regimes are qualitatively discussed prior to review of the applications in carbohydrate syntheses and transformation. This literature review looks at research involving glycosylations, -OH group conversions, isotopic incorporation, and C-N bond formation. Instances of improved yields and selectivities resultant from the use of these high-energy sources will be highlighted.