Categories: C-S Bond Formation >
Synthesis of thioesters
Recent Literature
Reduction of ethanethiol esters of α-amino acids to α-amino aldehydes by
triethylsilane and catalytic palladium-on-carbon is described. α-Amino aldehydes
with Boc, Cbz, or Fmoc protection could be obtained without racemization in high
yield.
H. Tokuyama, S. Yokoshima, S.-C. Lin, L. Li, T. Fukuyama, Synthesis, 2002, 1121-1123.
Diverse thiol esters were synthesized in good yields by reactions of thiophenol,
benzyl mercaptan, ethyl mercaptoacetate, and mercaptoacetic acid with N-acylbenzotriazoles
under mild conditions. These results demonstrate the utility of N-acylbenzotriazoles
as mild S-acylating agents.
A. R. Katritzky, A. A. Shestopalov, K. Suzuki, Synthesis,
2004,
1806-1813.
A convenient procedure allows the synthesis of esters and thioesters from the
corresponding carboxylic acid using TFFH as the coupling reagent. The
preparation of N-acyl-dithiocarbamates from carboxylic acids and
1,3-thiazolidine-2-thione is also described.
M. Pittelkow, F. S. Kamounah, U. Boas, B. Pedersen, J. B. Christensen, Synthesis,
2004, 2485-2492.
The facile and efficient conversion of a tert-butyl protecting group
to an acetyl protecting group by catalytic amounts of bromine in acetyl
chloride and the presence of acetic acid has been developed. The fairly mild reaction conditions are of particular interest for
new protecting group strategies for sulfur functionalised target structures.
A. Blaszczyk, M. Elbing, M. Mayor, Org. Biomol. Chem., 2004, 2,
2722-2724.
Various alcohols, phenols, amines and thiols
may easily be converted into acetate derivatives by treatment
with acetic anhydride in the presence of
acetonyltriphenylphosphonium bromide in good yields at room
temperature. With the same precatalyst, both aliphatic and aromatic aldehydes
can be transformed into the corresponding gem-diacetates under reflux
conditions.
A. T. Khan, L. H. Choudry, S. Ghosh, Eur. J. Org. Chem., 2005,
2782-2787.
Copper(II) tetrafluoroborate efficiently catalyzes acetylation of
structurally diverse phenols, alcohols, thiols, and amines with
stoichiometric amounts of Ac2O under solvent-free conditions at
room temperature. Acid-sensitive alcohols are smoothly acetylated without
competitive side reactions.
A. K. Chakraborti, R. Gulhane, Shivani, Synthesis, 2004,
111-115.
An atom efficient esterification could be
achieved using hafnium(IV) or zirconium(IV) salts.
K. Ishihara, M. Nakayama, S. Ohara, H. Yamamoto, Tetrahedron,
2002, 58, 8179-8188.
Acylation of alcohols, thiols, and sugars were studied with a variety of
Lewis acids, and it was found that Cu(OTf)2 was very efficient in
catalyzing the reaction under mild conditions in CH2Cl2.
K. L. Chandra, P. Saravan, R. K. Singh, V. K. Singh, Tetrahedron, 2002, 58,
1369-1374.
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