Catalyst‐Free Difunctionalization of Activated Alkenes in Water: Efficient Synthesis of β‐Keto Sulfides and Sulfones

Abstract

Difunctionalization of activated alkenes, a powerful strategy in chemical synthesis, has been accomplished for direct synthesis of a series of β-keto sulfides and β-keto sulfones. The transformation, mediated by O2 , proceeds smoothly in water and without any catalyst. Prominent advantages of this method include mild reaction conditions, purification simplicity, and gram-scale synthesis, underlining the practical utility of this methodology.

Iodine‐Triggered Aerobic Oxysulfonylation of Styrenes

“…In continuation of our research interest in iodine reagent‐mediated reactions, herein we report a metal‐free approach via an iodine‐triggered and expedient dioxygen activation method for the oxysulfonylation reaction towards the synthesis of β‐hydroxysulfones from styrenes (Figure a) . The aerial oxygen was activated for the introduction of an OH group at the benzylic position and the near quantitative synthesis of β‐hydroxysulfones was achieved from styrenes and sulfonyl hydrazides using pyridine as additive (10 mol%) and iodine (10 mol%) as catalyst .…”

Direct sulfonylation of anilines mediated by visible light

“…Sulfonyl radicals are transient intermediates that undergo a range of reactions, including with alkenes 7 and alkynes. 8 However, examples of their reactivity with aromatic rings are scarce: 1 the groups of Deng and Kuhakarn have independently reported sulfonylation of indoles at the C-2 position using sodium sulfinate salts under oxidative conditions, 9 Li and coworkers have reported on hypervalent iodine-mediated sulfonylation of anilides with aryl sulfonyl chlorides, 10 and sulfonyl radicals have been implicated in transition-metal-catalyzed directed C–H sulfonylations.…”

Advances in Oxosulfonylation Reaction

“…In the same year, Lei group [67] reported a catalyst‐free strategy for oxosulfonylation of activated alkenes (alkenes having a good leaving group at α ‐position like phosphate ester) 26a with aryl sulfinic acids 26b in water medium for synthesis of a series of β ‐keto sulfones 26c with up to 66% yield ( Scheme 26 ) . The authors also demonstrated that aryl thiols produced β ‐keto sulfides with good to excellent yields.…”

“…In light of its extensive efficacies, numerous protocols of oxosulfonylation such as metal-catalyzed oxosulfonylation, [46][47][48][49][50][51][52][53][54][55] organophotocatalyzed oxosulfonylation, [32,[56][57][58] metal-based photocatalyzed oxosulfonylation, [59][60][61] catalyst free photo-induced oxosulfonylation [62][63][64] etc have been developed. Very recently, oxygen triggered oxosulfonylation methods [65][66][67][68][69][70][71][72] show great interest among synthetic organic chemists.…”