A study of the alkylation and acylation of N-acylthiazolidinethione
نویسندگان
چکیده
Investigating the alkylation and acylation of N-acylthiazolidinethione, the desired α-alkylated products and C-acylated products are not obtained, but rather the S-alkylated products and O-acylated products are obtained. The possible mechanism proposed shows that the deprotonation agent and electrophilic species are responsible for the stability of enolates. The enolates derived from N-acylthiazolidinethiones are decomposed in the presence of base, but they are comparatively stable in the presence of Lewis acid. When electrophilic reagent is alkyl halide, the enolate decomposition is the dominating pathway, and affords the S-alkylated products; and when electrophilic reagent is acyl chloride, the formation of a highly ordered chelated transition-state is the dominating pathway, and affords the O-acylated products.
منابع مشابه
Potassium carbonate: a highly efficient catalyst for the acylation of alcohols, phenols and thiols under mild conditions
A general, mild and efficient protocol has been developed for the synthesis of esters and thioesters. The process has been taking place using tetra n-butylammonium iodide (TBAI) as a phase-transfer catalyst and in the presence of potassium carbonate (K2CO3). A wide range of esters and thioesters was prepared in high yields and suitable times by the treatment of alcohols, phenols and thiols with...
متن کاملSolvent-free direct ortho C-acylation of phenolic systems by methanesulfonic acid as catalyst
The use of methanesulfonic acid as a Brønsted acid for direct ortho-acylation of phenols and naphthols proves to be a convenient, more general and direct route to various hydroxyaryl ketones. The route is regioselective, leading to ortho C-acylated products in satisfactory to high yields in most cases. The solvent free reactions described below exhibited environmentally benign in terms of faste...
متن کاملChemical modifications of bafilomycin-type 16-membered dienlactone macrolides.
Derivatives of the 16-membered dienlactone bafilomycins were prepared in order to study the structure-activity relationship of these compounds. Some derivatives formed by hydrolysis, O-alkylation, O-acylation, trans-esterification and epoxidation were isolated and their structures determined by two-dimensional (2D) NMR studies and mass spectroscopy.
متن کاملChloromethyl-triazole: a new motif for site-selective pseudo-acylation of proteins† †Electronic supplementary information (ESI) available: Synthesis and characterisation of compounds 3b, 4b, and peptides Pep1–3. Peptide and protein alkylation procedures. See DOI: 10.1039/c6cc06801d. Primary data files can be found at http://dx.doi.org/10.7488/ds/1484 Click here for additional data file.
Rapid, site-selective modification of cysteine residues with chloromethyl-triazole derivatives generates pseudo-acyl sLys motifs, mimicking important post-translational modifications. Near-native biotinylation of peptide and protein substrates is shown to be site-selective and modified histone H4 retains functional activity.
متن کاملSolvent-free direct ortho C-acylation of phenolic systems by methanesulfonic acid as catalyst
The use of methanesulfonic acid as a Brønsted acid for direct ortho-acylation of phenols and naphthols proves to be a convenient, more general and direct route to various hydroxyaryl ketones. The route is regioselective, leading to ortho C-acylated products in satisfactory to high yields in most cases. The solvent free reactions described below exhibited environmentally benign in terms of faste...
متن کامل