Categories: S=O Bond Formation >
Synthesis of sulfones
Oxidation of sulfides with 30% hydrogen peroxide catalyzed by tantalum carbide provides the corresponding sulfoxides in high yields, whereas niobium carbide as catalyst efficiently affords the corresponding sulfones. Both catalysts can easily be recovered and reused without losing their activity.
M. Kirihara, A. Itou, T. Noguchi, J. Yamamoto, Synlett, 2010, 1557-1561.
2,2,2-Trifluoroacetophenone as organocatalyst enables a cheap, highly efficient, and selective synthesis of sulfoxides and sulfones starting from sulfides in the presence of H2O2 as the oxidant. The selectivity depends on the reaction conditions.
E. Voutyritsa, I. Triandafillidi, C. G. Kokotos, Synthesis, 2017, 49, 917-924.
The use of urea-hydrogen peroxide and phthalic anhydride in ethyl acetate enables a metal-free, environmentally benign oxidation of substituted sulfides to their corresponding sulfones without observation of the possible sulfoxide oxidation product.
M. Lutz, M. Wenzler, I. Likthotvorik, Synthesis, 2018, 50, 2231-2234.
Urea-hydrogen peroxide adduct is stable, inexpensive and an easily handled reagent. This reagent is used in an efficient solid state oxidation of different organic molecules: hydroxylated aldehydes and ketones (to hydroxylated phenols), sulfides (to sulfoxides and sulfones), nitriles (to amides) and nitrogen heterocycles (to N-oxides).
R. S. Varma, K. P. Naicker, Org. Lett., 1999, 1, 189-191.
1,3,5-Triazo-2,4,6-triphosphorine-2,2,4,4,6,6-tetrachloride (TAPC) is an efficient promoter for the oxidation of sulfides and deoxygenation of sulfoxides. Excellent yields, short reaction time, easy and quick isolation of the products, solvent-free process, and excellent chemoselectivity are the main advantages of this procedure.
K. Bahrami, M. M. Khodaei, M. S. Arabi, J. Org. Chem., 2010, 75, 6208-6213.
Use of a solvent with greater density than the fluorous phase is an alternative to the U-tube method in phase-vanishing reactions in cases where both reactants are less dense than the fluorous phase.
N. K. Jana, J. G. Verkade, Org. Lett., 2003, 5, 3787-3790.
Various aromatic and aliphatic sulfides are selectively oxidized to sulfoxides and sulfones in good to excellent yields using 30% H2O2 in the presence of a recyclable silica-based tungstate interphase catalyst at room temperature.
B. Karimi, M. Ghoreishi-Nezhad, J. H. Clark, Org. Lett., 2005, 7, 625-628.
Permanganate supported on active manganese dioxide can be used effectively for the oxidation of arenes, alcohols and sulfides under heterogeneous or solvent-free conditions.
A. Shaabania, P. Mirzaeia, S. Naderia, D. G. Leeb, Tetrahedron, 2004, 60, 11415-11420.
A facile I2O5-mediated direct oxidative coupling of aromatic alkenes with thiols provides various (E)-vinyl sulfones from readily available starting materials with excellent regioselectivity under metal-free conditions.
L. Wang, H. Yue, D. Yang, H. Cui, M. Zhu, J. Wang, W. Wei, H. Wang, J. Org. Chem., 2017, 82, 6857-6864.
β-Piperidinoethylsulfides can be oxidized by m-chloroperbenzoic acid to intermediates containing both N-oxide and sulfone functions. These undergo a Cope-type elimination to a vinylsulfone that can be captured by amines to afford β-aminoethylsulfones. The synthetic methodology developed can be utilized in multiple-parallel format and has numerous potential applications in medicinal chemistry.
R. J. Gruffin, A. Henderson, N. J. Curtin, A. Echalier, J. A. Endicott, I. R. Hardcastle, D. R. Newell, M. E. M. Noble, L.-Z. Wang, B. T. Golding, J. Am. Chem. Soc., 2006, 128, 6012-6013.
The reaction of 1-(methylthio)acetone with different nitriles in the presence of triflic anhydride gave 2-substituted 5-methyl-4-methylthio-1,3-oxazoles in good yield. The methylthio group at the C4 position can easily be removed with Raney nickel. 4-Methylsulfonyl derivatives were prepared by the oxidation of the MeS group with m-CPBA.