Metal-free three-component tandem cyclization for modular synthesis of 2,3-dihydrobenzothiazin-4-ones

Abstract

The first three-component cyclization reaction of benzo[c][1,2]dithiol-3-ones based on S–S bond cleavage is disclosed herein. A range of 2,3-dihydrobenzothiazin-4-ones were achieved in decent yields under mild conditions. The current synthesis route features advantages such as simple operation, readily available raw materials, transition-metal-free conditions, no protection of inert gases, good yields, excellent functional group compatibility and accessible scalability.