Microwave assisted rapid synthesis of bicyclo aza-sulfone derivatives from aldehydes via aldoxime formation followed by Michael addition-1,3-dipolar cycloaddition with divinyl sulfone in one-pot

Abstract

A catalyst-free and sustainable microwave method was developed for quick access to a diverse range of bridged bicyclo aza-sulfones from various aldehydes in one-pot via tandem Michael addition-1,3-dipolar cycloaddition of corresponding aldoximes and divinyl sulfone in acetonitrile. At first, microwave irradiation enables fast condensation of aldehydes using hydroxylamine to the corresponding aldoximes, which further reacts with divinyl sulfone in the same pot to afford the desired products, 7-oxa-4-thia-1-aza-bicyclo[3.2.1]-octane 4,4-dioxides in high yields in just 10 min. The one-pot strategy is endowed with a clean reaction profile, easy work-up and high yields.