Ammonium Iodide Induced Nonradical Regioselective Sulfenylation of Flavones via a C–H Functionalization Process

Abstract

A novel and highly regioselective ammonium iodide-induced nonradical sulfenylation method for the construction of a C-S bond was developed via C-H functionalization. With DMSO or R(1)SO2NHNH2 as a sulfenylating agent, MeS- and R(1)S-substituted flavone derivatives were obtained in good yields. This method enriches current C-S bond formation chemistry, making it a highly valuable and practical method in pharmaceutical industry.

BF3·SMe2 for Thiomethylation, Nitro Reduction and Tandem Reduction/SMe Insertion of Nitrogen Heterocycles

“…The classical method for installing a thioether moiety on an electron deficient aromatic substrate is via an S N Ar using thiolate salts as the nucleophile . Although thiolate salts are good nucleophiles, these types of reagents suffer from a range of drawbacks including volatility, instability, toxicity, and strong, unpleasant odors . Disulfides can also be used for the thiomethylation of aryl halides using nickel catalysts and zinc (Scheme a) or aryl diazaonium salts and boronic acids (Scheme c) under radical conditions although they are also known to be highly odorous.…”

KIO3‐Catalyzed Domino C(sp2)−H Bond Sulfenylation and C−N Bond Oxygenation of Enaminones toward the Synthesis of 3‐Sulfenylated Chromones

“…[3] During the past decade, the synthesis of chromones has drawn extensive interesta nd un-dergones ignificant advances. [4] Presently,t he available pathways toward the synthesis of chromone derivatives consist of two main types:a )the direct elaborationo fn aturally or commerciallya vailablec hromones [5] and b) domino reactions involvingt he constructiono ft he chromone ring and otherb ond transformations. [6] The former,a lthough theoretically simpler, suffers from the high cost and limited diversity of chromone substrates.…”

Dimethyl Sulfoxide: Yesterday's Solvent, Today's Reagent

“…Ammonium iodide was again used in the same year for the synthesis of methylthiolated flavones 85 in moderate to good yields (55–82%), this time by Zheng et al . In this transformation, substituted flavones 84 reacted with DMSO 1 as a sulfenylating agent in CH 3 CN at 135 °C (Scheme ).…”