Visible-Light-Enabled Decarboxylative Sulfonylation of Cinnamic Acids with Sulfonylhydrazides under Transition-Metal-Free Conditions

Abstract

Decarboxylative cross-coupling reactions of cinnamic acids with sulfonylhydrazides were explored using oxygen as the sole terminal oxidant, realizing a conceptually novel technology for vinyl sulfone synthesis under the synergistic interactions of visible light irradiation, organic dye-type photocatalyst eosin Y, KI, and Cs2CO3 at room temperature.

Sulfonyl Hydrazides in Organic Synthesis: A Review of Recent Studies

“…Normally, copper‐oxidant systems were efficient. Besides, both photosynthesis and electrosynthesis were also well investigated in these years. The radical addition to unsaturated bonds, C−H activation and coupling were all effective, which will be fully discussed herein.…”

“…The radical addition‐decarboxylation of cinnamic acids directly yielded substituted arenes . Cai and Huang developed the photoredox‐catalyzed and electric decarboxylative sulfonylations, leading to the synthesis of vinyl sulfones. Under the visible light irradiation, oxygen was used as the sole terminal oxidant (Eq.…”

A Convenient Synthesis of Sulfones via Light Promoted Coupling of Sodium Sulfinates and Aryl Halides

“…Classical methods for the preparation of sulfones [7] include the oxidation of sulfides, [8] electrophilic aromatic sulfonylation with sulfonyl chlorides, [9] transition metal catalyzed cross coupling of arylsulfinates and aryl halides, [10][11][12] and the insertion of sulfur dioxide. [14] The sulfonyl radicals are usually in-situ generated from sulfinic acid, [15] sodium sulfinate, [16] sulfonyl chloride, [17] sulfonyl hydrazide, [18] and SO 2 [19] promoted by photo-catalysts or oxidants. [14] The sulfonyl radicals are usually in-situ generated from sulfinic acid, [15] sodium sulfinate, [16] sulfonyl chloride, [17] sulfonyl hydrazide, [18] and SO 2 [19] promoted by photo-catalysts or oxidants.…”

“…[13] Recently, the reactions of sulfonyl radicals have received significant consideration in terms of synthetic efficiency and atom economy. [14] The sulfonyl radicals are usually in-situ generated from sulfinic acid, [15] sodium sulfinate, [16] sulfonyl chloride, [17] sulfonyl hydrazide, [18] and SO 2 [19] promoted by photo-catalysts or oxidants. Most of these methods encounter certain limitations including over-stoichiometric amounts of oxidants, harsh acid conditions, high reaction temperatures, and extra addition of metal-catalyst or photo-catalyst.…”

Recent Advances of Cinnamic Acids in Organic Synthesis

“…Next, we will introduce several radical synthesis of vinyl sulfones from cinnamic acids. As shown in Scheme , sodium sulfinates, disulfides, aryl sulfonate phenol esters [17 ° ] and TosMIC could all be used in these addition/decarboxylation transformations.…”