An Iron-Catalyzed Sustainable Functional Group Transfer Strategy for In-Water Transformation of Organic Sulfides to Sulfoxides by a Hydroxylamine-Derived Oxidant

Abstract

Herein, an unprecedented strategy for unlocking a new and efficient -NH to -O functional group transfer protocol to synthesize a variety of complex organic sulfoxides chemoselectively, starting from organic sulfides, in water is presented. This new functional group transfer protocol is based on harnessing the potential of metalloradical-assisted intermolecular functional group transposition or ‘InterGroupXfer’ to replace highly sensitive and reactive high-valent metal intermediates, [M = X] intermediates (X = O, NH). This sustainable functional group transfer strategy employs Earth-abundant iron catalyst and bench-stable and convenient-to-handle hydroxyl amine-derived surrogate, operates under mild conditions in water or even under solvent-free conditions, exhibits broad functional group tolerance, as well as versatility of reaction scale and proceeds without the use of any precious metal catalyst or additional oxidant. A comprehensive electronic and mechanistic investigation, supported by computaional calculations, has been conducted to elucidate the reaction mechanism. The utility of the developed methodology as well as studies of biological activity foster future pathways for exploring uncharted chemical space. The reported work with exceptional synthetic flexibility and operational simplicity aligns well with the prospect of green and sustainable chemistry and is expected to unlock new concepts in the emerging research area of catalytic functional group transfer reactivity.