Categories: S=O Bond Formation >
Synthesis of sulfoxides
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.
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.
A versatile procedure oxidizes sulfanes to sulfoxides without any overoxidation to sulfones using a combination of hydrogen peroxide and triflic acid. This method tolerates oxidatively sensitive functional groups.
M. M. Khodaei, K. Bahrami, A. Karimi, Synthesis, 2008, 1682-1684.
An excellent method for the selective oxidation of sulfides to sulfoxides with periodic acid (H5IO6) catalyzed by FeCl3 in MeCN has been devised. The reported procedure is fast, simple and the yields are excellent in most cases with reaction time of less than 2 minutes.
S. S. Kim, K. Nehru, S. S. Kim, D. W. Kim, H. C. Jung, Synthesis, 2002, 2484-2486.
A mild, efficient and environmentally friendly oxidation of sulfides to sulfoxides with a recyclable ion-supported hypervalent iodine reagent tolerates hydroxyl, nitrile, methoxy, carbon-carbon double bonds, and ester functionalities. Aliphatic and aromatic sulfides are selectively oxidized to the corresponding sulfoxides at room temperature in excellent yields without over-oxidation.
W. Qian, L. Pei, Synlett, 2006, 709-712.
Sc(OTf)3 is an efficient catalyst for the hydrogen peroxide mediated monooxidation of alkyl-aryl sulfides and methyl cysteine containing peptides. The method is high yielding, compatible with many widely used protecting groups, suitable for solid-phase applications and proceeds with minimum over-oxidation.
M. Matteucci, G. Bhalay, M. Bradley, Org. Lett., 2003, 5, 235-237.
An air and moisture tolerant complex of Ti(IV) with a C3-symmetric triphenolate amine ligand efficiently catalyzes sulfoxidation reactions at room temperature without previous activation using aqueous hydrogen peroxide as oxidant.
M. Mba, L. J. Prins, G. Licini, Org. Lett., 2007, 9, 21-24.
Confined chiral Brønsted acids catalyze asymmetric oxidations of a broad range of sulfides to sulfoxides with hydrogen peroxide. The wide generality and high enantioselectivity of the developed method is comparable even to the best metal-based systems.
S. Liao, I. Čorić, Q. Wang, B. List, J. Am. Chem. Soc., 2012, 134, 10765-10768.
The combination of very high ee values with high yield, the consequence of an efficient initial asymmetric oxidation followed by an efficient kinetic resolution, makes the reported system very practical for the asymmetric oxidation of simple akyl aryl sulfides.
C. Drago, L. Caggiano, R. F. W. Jackson, Angew. Chem. Int. Ed., 2005, 44, 7221-7223.
A chiral Fe(salan) complex serves as an efficient catalyst for asymmetric oxidation of sulfides using hydrogen peroxide in water without surfactant. Not only alkyl aryl sulfides but also various methyl alkyl sulfides were oxidized to the corresponding sulfoxides with high enantioselectivities.
H. Egami, T. Katsuki, J. Am. Chem. Soc., 2007, 129, 8940-8941.
The asymmetric oxidation of sulfides to chiral sulfoxides with hydrogen peroxide in good yield and high enantioselectivity has been catalyzed very effectively by a chiral vanadium-salan complex. The efficient kinetic resolution of racemic sulfoxides catalyzed by the vanadium-salan system is also described.
J. Sun, C. Zhu, Z. Dai, M. Xang, Y. Pan, H. Hu, J. Org. Chem., 2004, 69, 8500-8503.
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.
Oxidation of sulfides to sulfoxides with a catalytic amount of ceric ammonium nitrate reagent supported on silica gel has been achieved using stoichiometric sodium bromate as the primary oxidant. The heterogeneous CAN/NaBrO3 reagent enables the use of an organic solvent and simplifies the reaction work-up and product isolation.
M. H. Ali, D. Kriedelbaugh, T. Wencewicz, Synthesis, 2007, 3507-3511.
5-Ethyl-3-methyl-2′,4′:3′,5′-di-O-methylenedioxy-riboflavinium perchlorate, which is readily derived from commercially available vitamin B2, exhibits high catalytic activity for the oxidation of organic sulfides under an oxygen atmosphere with the assistance of hydrazine hydrate as a reductant. This is an inexpensive, convenient, and environmentally benign method for the selective oxidative transformation of sulfides into sulfoxides.
Y. Imada, I. Tonomura, N. Komiya, T. Naota, Synlett, 2013, 24, 1679-1682.
Oxidations of organic substrates such as sulfides, secondary amines, N-hydroxylamines, and tertiary amines with molecular oxygen in the presence of 5-ethyl-3-methyllumiflavinium perchlorate catalyst and hydrazine monohydrate in 2,2,2-trifluoroethanol occur highly efficiently to give the corresponding oxidized compounds in excellent yields.
Y. Imada, H. Iida, S. Ono, S.-I. Murahashi, J. Am. Chem. Soc., 2003, 125, 2868-2869.
Urea-hydrogen peroxide adduct (UHP) is stable, inexpensive and an easily handled reagent. UHP 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.