C=S Bond Formation
Name Reactions
Recent Literature
A simple, efficient, and new method has been developed for the synthesis of
thioamides from nitriles. The reaction of a variety of aromatic and
aliphatic nitriles in the presence of phosphorus pentasulfide afforded the
corresponding thioamides in high yields. This method is easy, rapid, and
high-yielding for the synthesis of thioamides from nitriles.
B. Kaboudin, D. Elhamifar, Synthesis, 2006, 224-226.
An expeditious, solvent-free, and high yield conversion of ketones, flavones,
isoflavones, lactones, amides, and esters to the corresponding thio
analogues is described utilizing Lawesson's reagent in a process that
circumvents the use of dry solvents and excess of the reagent.
R. S. Varma, D. Kumar, Org. Lett., 1999, 1, 697-700.
A novel, simple and convenient thionation protocol for carbonyl compounds with
the system PSCl3/H2O/Et3N allows a clean,
rapid, and efficient synthesis of a variety of thiocarbonyl compounds such as
thioamides, thiolactams, thioketones, thioxanthones and thioacridone under
solventless condition with microwave irradiation.
U. Pathak, L. K. Pandey, R. Tank, J. Org. Chem., 2008,
73, 2890-2893.
Thionation of amides, 1,4-diketones, N-(2-oxoalkyl)amides, and N,N'-acylhydrazines
with the use of a fluorous Lawesson's reagent leads to thioamides, thiophenes,
1,3-thiazoles, and 1,3,4-thiadiazoles in high yields. The isolation of the final products is achieved in most cases by a
simple filtration.
Z. Kaleta, B. T Makowski, T. Soos, R. Dembinski, Org. Lett.,
2006, 8, 1625-1628.
A microwave-enhanced variation of the Kindler thioamide synthesis is
introduced. The three-component condensations of aldehydes, amines, and
elemental sulfur were carried out using 1-methyl-2-pyrrolidone (NMP) as solvent
employing microwave flash heating at 110-180°C for 2-20 min. A simple workup
protocol allows the isolation of synthetically valuable primary, secondary, and
tertiary thioamide building blocks in good yield and purity (>90%).
O. I. Zubruyev, N. Stiasni, C. O. Kappe, J. Comb. Chem., 2003, 5, 145-148.
Endothiopeptides can easily be obtained via Ugi reaction using thio acids as
acid components. If isonitriles with an acetal group are applied, the
endothiopeptides can directly be converted into thiazoles using TMSCl-NaI
under microwave irradiation.
U. Kazmaier, S. Ackermann, Org. Biomol. Chem., 2005, 3, 3184-3187.
