Copper Acetate–DMSO Promoted Methylthiolation of Arenes and Heteroarenes

Abstract

An unprecedented copper acetate-DMSO promoted methylthiolation of arenes and heteroarenes in the presence of air has been developed. The reaction is highly regioselective under the directing group influence of pyridine and pyrimidine functional units and gives the thiomethylated product in moderate to high yields.

The Applications of Dimethyl Sulfoxide as Reagent in Organic Synthesis

“…The related mechanistic studies indicate that the oxidant (K 2 S 2 O 8 ) plays an important role in the releasing of the thiomethyl group from DMSO. Similar to this work, very recently, Jain and co‐workers34 have reported a copper acetate‐DMSO‐promoted methylthiolation of (hetero)arenes in the presence of air (Scheme b). This reaction is highly regioselective under the directing group influence of pyridine and pyrimidine functional group units and gives the corresponding thiomethylated product in moderate to high yields.…”

A comprehensive overview of directing groups applied in metal-catalysed C–H functionalisation chemistry

“…The use of DMSO as reactant for the methylthiolation of similar substrates was reported by Jain via a Cu-mediated reaction ( Scheme 120C ). 729 Arylthiolation was reported by Zhang using N -(arylthio)benzamides, 730 while sulphonylation can be performed via an Umpolung reaction with hypervalent iodine compounds, followed by reaction with sodium sulphinates 731 ( Scheme 120D and E ). Notably, the latter method is also suitable for the reaction with other nucleophiles.…”

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

“…[10][11][12][13] Disulfides can also be used for the thiomethylation of aryl halides using nickel catalysts and zinc [14][15][16][17][18][19][20] (Scheme 1a) or aryl diazaonium salts [21] and boronic acids [22] (Scheme 1c) under radical conditions although they are also known to be highly odorous. Recently, DMSO has emerged as an attractive thiomethyl source for the functionalization of a range of substrates [23][24][25][26][27][28][29] (Scheme 1a and Scheme 1b) however, these reactions require high temperatures as well as the use of stoichiometric amounts of copper salts.…”