Categories: C-S Bond Formation >
Synthesis of isothioureas
A three-component coupling reaction of alcohols or thiols with N,N-dibromoarylsulfonamides and isonitrile and in the presence of K2CO3 provides both isoureas and isothioureas in very good yields. This metal-free process proceeds via carbodiimide intermediate at room temperature within a very short reaction time.
D. Mishra, P. Phukan, J. Org. Chem., 2021, 86, 17581-17593.
A simple and efficient copper-catalyzed S-arylation of arylthioureas provides aryl-isothioureas. This ligand-free method offers good yield, short reaction time, and broad substrate scope.
H. Zhu, X. Liu, C.-Z. Chang, Z.-B. Dong, Synthesis, 2017, 49, 5211-5216.
Direct reaction of isocyanides with sulfoxides affords thiocarbamic acid S-esters in very good yields. In addition, multicomponent reactions involving isocyanide, sulfoxide, and a suitable nucleophile provide a diverse range of sulfur-containing compounds, including isothioureas, carbonimidothioic acid esters, and carboximidothioic acid esters.
S. Wu, X. Lei, E. Fan, Z. Sun, Org. Lett., 2018, 20, 522-525.
A clean and economic synthesis of alkanesulfonyl chlorides via bleach-mediated oxidative chlorosulfonation of S-alkyl isothiourea salts is simple, environment- and worker-friendly. The procedure uses readily accessible reagents, offers safe operations and easy purification without chromatography, and affords high yields.
Z. Yang, B. Zhou, J. Xu, Synthesis, 2014, 46, 225-229.