Chapter Five - Application of sonochemical activation in synthetic organic chemistry

Abstract

In recent years the use of ultrasonic irradiation (i.e., sound wave with frequency higher than 20kHz) in promoting synthetic reactions in organic chemistry became remarkably fashionable. Indeed the accompanying phenomena of ultrasonic irradiation, such as the increased mass transfer, formation of bubbles with local hot spots with exceedingly high temperature and pressure, and the emerging shock waves on collapsing the bubbles may result in unexpected reactions and transformation pathways and/or unusual chemo- and/or enantioselectivities. Careful experimentation makes ultrasonic irradiation a useful tool in the hands of synthetic chemists. Moreover, when the sonochemical activation is coupled with microwave and/or flow chemistry, even complex multistep and multicomponent reactions can be performed rapidly and efficiently in one pot. This approach clearly provides green alternative to “conventional” ways of organic syntheses.