Visible-Light-Induced Decarboxylative Aminosulfonylation of (Hetero)aryl Carboxylic Oxime Esters

Abstract

Sulfonamides are important structures in pharmaceuticals, agrochemicals, and organocatalysts, yet the rapid and benign synthesis of these compounds is still a great challenge. Herein we report a photoinduced method for synthesizing sulfonamides from (hetero)aryl carboxylic acid oxime esters. This reaction proceeds via one-pot cascade radical−radical crosscoupling by energy-transfer-mediated photocatalysis. A wide substrate scope including (hetero)aryl substrates and late-stage modification of pharmaceutical molecular entities reveal its generality.

Difunctionalization of gem-difluoroalkenes for amination and heteroarylation via metal-free photocatalysis

“…Based on the experimental facts mentioned above and previous reports, 23,27,31 we proposed a possible reaction mechanism as shown in Scheme 5. First, under the irradiation of suitable wavelength light, thioxanthone (TXT) is excited to a triplet excited state.…”

“…Since 2019, oxime derivatives have been widely used in various reactions, such as decarboxylative functionalization of aryl and alkyl carboxylic acids, 23 decarboxylative imination, 24,25 decarboxylative fluorosulfonylation of aryl and alkyl carboxylic acids 26,27 and dual functionalization of various structures. 28–34 These reactions involve the generation of N - and O -centered radicals through energy-transfer (EnT) in the presence of suitable photocatalysts with high triplet excited state energy and appropriate light sources.…”

“…28–34 These reactions involve the generation of N - and O -centered radicals through energy-transfer (EnT) in the presence of suitable photocatalysts with high triplet excited state energy and appropriate light sources. Based on the previous work from our group on functionalization of gem -difluoroalkenes and heteroaryl carboxylic oxime esters, 12,27 we attempted to utilize readily available oxime derivatives to provide imino and heteroaryl radicals for amination and heteroarylation of gem -difluoroalkenes simultaneously (Scheme 1b).…”

Photocatalytic Synthesis and Functionalization of Sulfones, Sulfonamides and Sulfoximines

“…This year, Yang et al designed the synthesis of sulfonamides 35 employing (hetero)aryl carboxylic acid oxime esters 34 in a one-step process under blue light irradiation (440 nm, Figure 12). [49] This transformation relies on an EnT process from the excited [Ir]-1 PC to 34 to produce the key carbon-and nitrogencentered radicals XXIX and XXX, respectively. In a radical cascade, XXX reacts with SO 2 and then the so-obtained sulfonyl radical XXXI couples with the iminyl radical counterpart XXX to deliver the final product 35.…”

Photoinduced EnT-mediated sulfonamidylimination of alkenes and (hetero)arenes with iminophenylacetic acid oxime esters

“…Pioneered by Glorius and Cho, 8 photo-sensitized energy transfer (EnT)-mediated cleavage of the N–O/S bond of well-designed oxime or sulfonylamide-based bifunctional reagents has emerged as a powerful technique for the amination of alkenes. 9 By using this protocol, the Yang and Glorius groups independently reported the unsymmetrical diamination of alkenes with oxime esters derived from commercially available hydroxycarbamate, methyl 2-bromo-2-methylpropanoate, benzophenone oxime and different hydroxylamines (Scheme 1b). 10 It is noteworthy that the reaction also offers unique advantages in dearomatization of (hetero)arenes.…”