Synthesis of Aryl Sulfides: Metal-Free C–H Sulfenylation of Electron-Rich Arenes

Abstract

A simple, efficient, and practical metal-free C-H sulfenylation of substituted electron-rich arenes has been developed. This method is highly regioselective, and the corresponding aryl sulfides were obtained in moderate to excellent yields from stable and readily accessible N-(alkylthio)- and N-(arylthio)succinimides at room temperature in the presence of TFA.

Solvent‐ and Metal‐Free Chalcogenation of Bicyclic Arenes Using I2/DMSO as Non‐Metallic Catalytic System

“…IR (KBr): ν = 3402, 3350, 3061, 1596, 1484, 1461, 1387, 1220 . HRMS (APPI + ): m/z calcd for C 16 3, 135.6, 133.1, 132.8, 130.4, 129.6, 129.5, 128.8, 128.7, 128.2, 126.8, 123.9, 116.7, 108.8 ppm. IR (KBr): ν = 3364, 3058, 1593, 1568, 1475, 1436, 1384, 1196 9, 135.9, 131.7, 129.4, 128.6, 127.5, 126.9, 123.6, 116.2, 109.9, 32.4 (CH 2 ), 28.8 (CH 2 ), 22.7 (CH 2 ), 13.4 (CH 3 ) ppm.…”

Gold-Catalyzed Synthesis of 2-Sulfenylspiroindolenines via Spirocyclizations

“…Starting from N-nosyltryptamine 5a (R = H) and N-nosyltryptophane ethyl ester 5b (R = CO2Et), we have envisaged to functionalize them using the metal-free electrophilic sulfenylation reported by Cossy [20,21], because of its simplicity and efficiency. We first exposed tryptamines 5 to propargyl bromide and successfully set up the propargyl group in good yields (Scheme 2).…”

Sulfenylation of C–H Bonds for C–S Bond Formation under Metal‐Free Conditions

“…This method was regioselective, and moderate to excellent yields were obtained (Scheme ). A mechanism was proposed for this TFA‐induced C–H sulfenylation: an electrophilic thio intermediate of type B , generated through the reaction between TFA and the N ‐(arylthio)‐ or N ‐(alkylthio)succinimide, undergoes nucleophilic attack on the electron‐rich arene to produce the desired sulfenylated product D and succinimide as the by‐product . In the same year, the same group also achieved the sulfenylation of indoles under similar reaction conditions …”