Visible-Light-Promoted Oxo-Sulfonylation of Ynamides with Sulfonic Acids

Abstract

A visible-light-promoted oxo-sulfonylation of ynamides with sulfonic acids is reported, giving rise to a collection of functionalized α-sulfonylated amides in a straightforward manner. The reaction proceeds sequentially through a cascade of electrophilic addition and photoinduced sulfonyl radical-sustained skeleton rearrangement. The high atom economy, mild reaction conditions, and wide substrate scope comprised the merits of this synthetic transformation.

Metal‐Free Hydrophosphoryloxylation of Ynamides: Rapid Access to Enol Phosphates

“…[13] For instance, Lam et al [14] and Bi et al [15] achieved the regioselective hydroacyloxylation of ynamides with carboxylic acids under palladium catalysis and metal-free conditions, respectively. Besides, metal-free additions of hydrogen halides [16] and sulfonic acids [17] to ynamides were also well documented. Prompted by these precedents and our continuing interests in ynamide chemistry, [18] we envisioned that phosphoric acid might undergo addition with ynamides to yield useful enol phosphates.…”

Advances in Oxosulfonylation Reaction

“…Another metal‐based photoredox catalyzed oxosulfonylation method was introduced by Feng group [61] in 2019. According to this visible light promoted oxosulfonylation reaction, ynamide 20a was reacted with sulfonylating reagent, sulfinic acid 20b in presence of 0.2 mol% of [Ir(dF(CF 3 )ppy) 2 (4,4‐CF 3 bpy)](PF 6 ) as photocatalyst in acetonitrile under inert atmosphere and blue light irradiation to achieve α‐sulfonylated amides 20c ( Scheme 20 ) .…”

“…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.…”

Electrochemically Promoted Bifunctionalization of Alkynes for the Synthesis of β‐Keto Sulfones

“…[18,19] Moreover, alkynes were successfully applied to the synthesis of β-keto sulfones by metal catalysis or photocatalysis (Scheme 1e). [20][21][22][23][24] A manganese (III)-mediated and -catalyzed synthesis of β-keto sulfones via arylpropiolic acids with sodium sulfonates was developed using Mn(OAc) 3 (Scheme 1f). [25] In addition, β-keto sulfones were also synthesized by a copper(I)-catalyzed multicomponent reaction of aryldiazonium tetrafluoroborates, 3-arylpropiolic acids, sulfur dioxide and water at 0 °C.…”