Categories: C-S Bond Formation >
Synthesis of benzylic sulfides
TAPC efficiently catalyzes the reaction of benzylic alcohols with aryl, heteroaryl, and alkyl thiols to afford thioethers in good to excellent yields. Furthermore, the reaction proceeds under metal-free and solvent-free conditions thus represents an interesting complement to known methods for thioether synthesis. A plausible mechanism is given.
K. Bahrami, M. M. Khodaei, N. Khodaboustan, Synlett, 2011, 2206-2210.
An efficient, indium triiodide-catalyzed substitution of the acetoxy group in alkyl, benzyl, allyl, and propargyl acetates with thiosilanes provides access to various thioethers.
Y. Nishimoto, A. Okita, M. Yasuda, A. Baba, Org. Lett., 2012, 14, 1846-1849.
A zinc-catalyzed regioselective hydrothiolation of styrenes with thiols was achieved in the presence of 4-toluenesulfonic acid to provide Markovnikov-type sulfides in very good yields.
N. Taniguchi, J. Org. Chem., 2020, 85, 6528-6534.
The use of environmentally friendly aryl dithiocarbamates and commercially available benzyl halides as starting materials, CuCl as catalyst and Cs2CO3 as base enables an odorless and efficient protocol for the synthesis of benzyl phenyl sulfides.
Y. Zhou, C.-L. Yang, L. Ye, Z.-B. Dong, Synthesis, 2022, 54, 4104-4110.
S-Alkyl, S-aryl, and S-vinyl thiosulfate sodium salts (Bunte salts), which can readily be prepared from sodium thiosulfate, react with Grignard reagents to give sulfides in good yields. The reaction is amenable to a broad structural array of Bunte salts and Grignard reagents. Importantly, this route to sulfides avoids the use of malodorous thiol starting materials or byproducts.
J. T. Reeves, K. Camara, Z. S. Han, Y. Xu, H. Lee, C. A. Busacca, C. H. Senanayaka, Org. Lett., 2014, 16, 1196-1199.
KOH promotes an unusual deoxidative coupling reaction of β-sulfinyl esters with benzylic trimethylammonium salts to produce thioethers. Enantiomerically enriched quaternary ammonium salts provide benzyl thioethers with clean inversion of the configuration.
Q. Zhang, H. Feng, F. Chen, Z. He, Q. Zeng, J. Org. Chem., 2021, 86, 7806-7812.
A reducing system combined with InBr3 and 1,1,3,3-tetramethyldisiloxane (TMDS) enables a direct thioetherification of various aromatic carboxylic acids and thiols in a one-pot procedure, whereas a system combined with InI3 and TMDS underwent thioetherification of aliphatic carboxylic acids with thiols.
N. Sakai, T. Miyazaki, T. Sakamoto, T. Yatsuda, T. Moriya, R. Ikeda, T. Konakahara, Org. Lett., 2012, 14, 4366-4369.
Treatment of methylarenes with 1,3-dibromo-5,5-dimethylhydantoin or N-bromosuccinimide and a catalytic amount of 2,2′-azobis(isobutyronitrile) followed by a reaction with a nucleophile, such as benzoic acid, p-toluenethiol, sodium p-toluenesulfinate, aqueous dimethylamine, or succinimide, provides the corresponding benzylated products in good yields.
H. Shimojo, K. Moriyama, H. Togo, Synthesis, 2015, 47, 1280-1290.
In a one-pot, sequential benzyne activation and nucleophilic substitution of enantioenriched tertiary benzylic amines, a range of enantioenriched tertiary benzylic amines were substituted by various nucleophiles in the presence of 2-(trimethylsilyl)phenyl triflate and CsF, to provide structurally diverse benzylic compounds in moderate to excellent yields with excellent retention of enantiopurity.
Y. Gui, S.-K. Tian, Org. Lett., 2017, 19, 1554-1557.
In three odorless methods for the thioarylation and thioalkylation of different nitroarenes using alkyl halides (Br, Cl), triphenyltin chloride, and arylboronic acids as the coupling partners, Na2S2O3·5H2O, S8/KF, and S8/NaOH systems are found to be effective sources of sulfur in the presence of copper salts. The methods offer use of green solvents, inexpensive catalysts, and user-friendly starting materials.
A. Rostami, A. Rostami, A. Ghaderi, J. Org. Chem., 2015, 80, 8694-8704.
A facile and sustainable protocol for the thiolation of hydrazones with sodium sulfinates in the presence of CuBr2 and DBU in DMF provides diverse benzylic thioethers. Control experiments reveal a radical pathway involving a thiyl radical as a key intermediate.
A. K. Pandey, S. Chand, A. K. Sharma, K. N. Singh, J. Org. Chem., 2023, 88, 475-482.