Universal solvent DMSO

The unknown face of DMSO
First, participate in hydroxyl oxidation reaction
Two well-known oxidation reactions involving DMSO are swern oxidation and Pfitzner-Moffatt oxidation, both of which are used to oxidize alcohols to aldehydes or ketones. Among them, the oxidation of swern in partnership with oxaloyl chloride usually reacts in methylene chloride at -78 ° C to avoid the risk of explosion (DOI:10.1021/jo00882a030). Pfitzner-Moffatt oxidation, on the other hand, uses DCC of more than 3 equivalent and strong acidic conditions to activate DMSO to achieve oxidation (DOI:10.1021/ja00952a026).

Second, cooperate with iodine oxidation rearrangement
In 2023, Professor Jiao Ning’s research group at Peking University reported a new iodine-catalyzed oxidative rearrangement of DMSO and cyclobutenones, which successfully completed the construction of a series of furan-2 (5H) -ketone molecules. In this reaction, iodine was used as catalyst in MeNO2 reaction solvent, the reaction temperature was 100℃, and finally the product yield was 84%. Nitromethane itself is more dangerous, in Jiao’s conditional screening also mentioned that toluene can give the corresponding product at 75% yield, you can try to avoid nitromethane (doi:10.1039/D3GC01756G).

3. Catalyze aryl chloride
The same team of Professor Junning published in NatureCatalysis in 2020 the C-H bond chlorination of a series of (hybrid) aromatic hydrocarbons using chlorination reagent NCS in combination with DMSO. The reaction can be successfully completed at room temperature, and it is not only suitable for simple molecules, but also for the late modification of complex natural products, drug molecules and peptides. The reaction can be performed in a chloroform system at room temperature (doi.org/10.1038/s41929-019-0398-0).

4. It collaborates with iodine to catalyze intramolecular C-H and N-H activation coupling
In 2021, the research team of Professor Zhou Haifeng of China Three Gorges University reported the intramolecular C(sp3)-H/N-H oxidation cross-coupling reaction of a simple catalytic system. In this method, 2-(benzyl amino) benzamide compounds were used as raw materials to form C-N bonds through I2/ DMSO-mediated intramolecular oxidation cross-coupling. The method was characterized by good functional group tolerance and high yield. In addition, the method in gram scale reaction can also get more than 90% of the yield (DOI: 10.1002 / ejoc. 202101187).
Detailed coupling of C-H,N-H activation in coordination with iodine.png
Activation of DMSO involved in pyrimidine ring synthesis
In 2020, the team of Tao-ShanJiang (not found, if you know something can inform the small series) at Anhui Agricultural University reported the method of using activated DMSO to complete pyrimidine ring synthesis. The method uses amidine hydrochloride, ketone and dimethyl sulfoxide to directly synthesize pyrimidine through substrate-induced dimethyl sulfoyl activation and subsequent reaction. In this scheme, amidine hydrochloride is not only used as a reactant, but also activates dimethyl sulfoxide to form a thionite intermediate, which then participates in the reaction to complete the synthesis of pyrimidine (DOI:10.1039/d0qo01416h).

6. Participated in the skeleton synthesis of quinoline catalyzed by cobalt
In 2017, Professor Yi Wei’s team at Guangzhou Medical University reported a unique Co(III) catalyzed simple, cheap and readily available C−H activation/cyclization of aniline and alkynes with the participation of dimethyl sulfoxide for the direct and efficient synthesis of privileged quinoline with exclusive regional selectivity and wide substrate/functional group tolerance with good to excellent yield. Dimethyl ether is used as the solvent and C1 building group of quinoline products. Mechanism of the experimental results show that the reaction may adopt multi-function 2 – vinyl aniline species as reactive intermediates (DOI:10.1021/acs.org lett. 7 b03673).

7, used for the synthesis of methyl thiomethyl ester or methyl ether
In 2022, Professor Yang Xiaosheng’s team at Guizhou Medical University reported a method of synthesizing methylthiomethyl ester or methyl ether using DMSO. It can be used to prepare methionyl ester/ether directly from carboxylic acid/phenol and dimethyl sulfoxide (DMSO) as solvent and methionyl source. In the case of different types of carboxylic acids/phenols, the reaction transitions smoothly, providing the corresponding MTM esters/ethers at moderate to excellent yields. This method has no catalyst, easy operation, wide range of substrates, good functional group tolerance, to participate in the formation of dimethyl sulfoxide enolization content and other characteristics (doi.org/10.1039/D2RA06618A).

8, under the action of NBS and carboxylic acid to complete cross dehydrogenation
In 2020, Professor Tang Lin’s team at Xinyang Normal University reported the transition metal-free cross dehydrogenation of carboxylic acid with DMSO using NBS promoted for the formation of formal C-O bonds via Pummerer-type rearrangement. These conversions use readily available carboxylic acids as nucleophiles and DMSO as sour-containing carbon sources and solvents under mild conditions, providing valuable methyl esters with a wide range of substrates. In addition, the scheme provides a development by using deuterium labeling DMSO as a reagent preparation of methyl deuterium generation (doi.org/10.1039/D0QO00617C) effective and direct way.

9. Participate in the iodohydroxylation of olefin as an oxygen source
In 2017, Professor Jiao Ning’s research group reported an oxidative iodohydroxylation reaction of olefin, which uses cheap iodide and common solvent DMSO as oxidant, providing a new method for the synthesis of iodoalcohol. DMSO plays a key role in this reaction, acting as oxidant, solvent and oxygen source. This method enables the iodoetheration of olefin by switching to a more nucleophilic solvent (DOI:10.6023/a17100448).
Detail of iodohydroxylation of olefin as an oxygen source.png
DMSO/KOH/H2O2 hydrolyzes cyanide group
This is the special use of DMSO that we have cited countless times, at room temperature, 5-30 minutes to complete the reaction, is a very practical method of hydrolyzing nitrile to prepare amide. In the previous projects, many cyanogen hydrolysis processes have adopted this method. This scheme was first reported in SYNTHESIS in 1989 (DOI:10.1055/s-1989-27441).

Of course, the magic function of DMSO is far more than the above ten kinds, Xiaobian can not introduce all in a tweet, I hope you understand. Small partners who have a deeper understanding of this kind of reaction are also welcome to add small friends to communicate.