Rongalite as the C1 synthon to assemble 2,3-dihydrobenzothiazin-4-ones and benzo[d][1,3]oxathiin-4-ones

Abstract

A facile divergent construction of sulfur-containing heterocycles via a skeletal reorganization strategy is presented herein, in which the versatile and readily available rongalite was utilized as the C1 synthon. This organic-phosphine facilitated divergent transformations of benzo[c][1,2]dithiol-3-ones via S atom swapping reaction, enabling the streamlined construction of a sequence of 2,3-dihydrobenzothiazin-4-ones and benzo[d][1,3]oxathiin-4-ones under mild conditions. This newly-discovered skeletal reorganization strategy is transition-metal-free, insensitive to moisture and air, and characterized by convenient operation, good yields and broad substrate scope.