Categories: S-H Bond Formation >
Reduction of sulfoxides
Recent Literature
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.
The combination of triflic anhydride and potassium iodide was an effective
promoter for the deoxygenation of sulfoxides and gave the corresponding sulfides
in excellent yield in acetonitrile at room temperature. This reagent system is
chemoselective and tolerates various functional groups, such as alkenes,
ketones, esters, aldehydes, acids, and oximes.
K. Bahrami, M. M. Khodaei, A. Karimi, Synthesis, 2008,
2543-2546.
Sodium borohydride in the presence of iodine in anhydrous THF converts
various sulfoxides to their thioethers in excellent yields. A chemoselective
deoxygenation of sulfoxides can be achieved in the presence of other
reducible functional groups such as esters, nitriles and double bonds.
B. Karimi, D. Zareyee, Synthesis, 2003, 335-336.
In a mild reduction of sulfoxides, sulfides are obtained in excellent yields
when aliphatic and aromatic sulfoxides were treated with SOCl2 as a
catalyst and Ph3P in THF at room temperature.
Y. Jang, K. T. Kim, H. B. Jeon, J. Org. Chem., 2013,
78, 6328-6331.
A dichlorodioxomolybdenum(VI)-catalyzed oxotransfer allows a chemoselective
deoxygenation of sulfoxides to sulfides in the presence of P(OPh)3 as
the stoichiometric reductant.
R. Sanz, J. Escribano, R. Aguado, M. R. Pedrosa, F. J. Arnáiz, Synthesis, 2004,
1629-1632.
Various alkyl and aryl sulfoxides have been successfully deoxygenated using
3-mercaptopropionic acid as a reducing agent and a catalytic amount of
either NBS or I2 in MeCN at ambient temperature. Under the
described reaction conditions, acid sensitive substrates such as acetals
remained intact.
B. Karimi, D. Zareyee, Synthesis, 2003, 1875-1877.
Sulfoxides and aza-aromatic N-oxides were deoxygenated using a system
of indium and pivaloyl chloride at room temperature to give the
corresponding sulfides and aza-aromatics in high yields.
E. S. Park, S. Hwan, Lee, J. H. Lee, H. J. Rhee, C. M. Yoon, Synthesis, 2005, 3499-3501.
A sulfoxide reduction/C-S bond metathesis cascade between sulfoxides and
alkyl bromides in an ionic liquid provides high-value sulfides without the use
of any catalysts or bases. In this cascade, classical Kornblum oxidation is
employed to reduce sulfoxides with alkyl bromides. This protocol features high
functional tolerance, mild conditions, promising scalability, and a sustainable
solvent.
C. Liu, D. Chen, Y. Fu, F. Wang, J. Luo, S. Huang,
Org. Lett., 2020, 22, 5701-5705.