15119-62-7Relevant academic research and scientific papers
Diazepinium perchlorate: a neutral catalyst for mild, solvent-free acetylation of carbohydrates and other substances
Giri, Santosh Kumar,Gour, Rajesh,Kartha, K. P. Ravindranathan
, p. 13653 - 13667 (2017/03/11)
Diazepinium perchlorate, an essentially neutral organic salt possessing excellent stability, has been found to be well suited for the acetylation of free as well as partially protected sugars, phenols, thiophenols, thiols and other alcohols as well as amines. The diazepinium perchlorate-catalyzed acetylation is mild, organic and solvent-free and leaves acid sensitive protecting groups such as TBDMS/TBDPS/Tr ethers and isopropylidene/benzylidene acetals present on a substrate unaffected. Regioselective hydroxyl protection in partially protected carbohydrate derivatives/polyhydroxylic compounds was possible and was proved to be a convenient time-saving alternative to the conventional synthesis of such compounds. Easy preparation of the catalyst, mild reaction conditions and an environmentally benign protocol are some of the notable features of this reaction. The results obtained on the acetylation of phenols and thiophenols could be rationalized through their local nucleophilicity index obtained from DFT calculations.
Acyl transfer reactions of carbohydrates, alcohols, phenols, thiols and thiophenols under green reaction conditions
Giri, Santosh Kumar,Kartha, K. P. Ravindranathan
, p. 11687 - 11696 (2015/02/19)
Acyl transfer reactions of various carbohydrates, alcohols, phenols, thiols and thiophenols were achieved at room temperature in high yields and catalytic efficiency in the presence of methane sulfonic acid, a green organic acid, under solvent-free conditions over short time periods. The method is mild enough to allow acid labile substituents such as isopropylidene acetals and trityl ethers on the reacting substrates to be left completely unaffected. Esterification of free mono- and dicarboxylic acids such as acetic acid, cinnamic acid, sialic acid and tartaric acid with alcohols such as menthol, ethanol, methanol or propylene glycol has also been achieved efficiently at room temperature. A comparative study of the method with the silica-sulfuric acid is also reported.
Mild Ti-mediated transformation of t-butyl thio-ethers into thio-acetates
Pijper, Thomas C.,Robertus, Jort,Browne, Wesley R.,Feringa, Ben L.
supporting information, p. 265 - 268 (2015/01/16)
We report a straightforward method for the rapid conversion of thio-ethers to thio-acetates using TiCl4, in good to excellent yields. The reaction conditions tolerate a variety of functional groups, including halide, nitro, ether, thiophene and acetylene functionalities. A catalytic variant of this reaction is also described. This journal is
Efficient Cu-catalyzed base-free C-S coupling under conventional and microwave heating. A simple access to S-heterocycles and sulfides
Soria-Castro, Silvia M.,Penenory, Alicia B.
supporting information, p. 467 - 475 (2013/05/08)
S-aryl thioacetates can be prepared by reaction of inexpensive potassium thioacetate with both electron-rich and electron-poor aryl iodides under a base-free copper/ligand catalytic system. CuI as copper source affords S-aryl thioacetates in good to excellent yields, by using 1,10-phenanthroline as a ligand in toluene at 100°C after 24 h. Under microwave irradiation the time was drastically reduced to 2 h. Both procedures are simple and involve a low-cost catalytic system. This methodology was also applied to the "one-pot" synthesis of target heterocycles, such as 3H-benzo[c][1,2]dithiol-3-one and 2-methylbenzothiazole, alkyl aryl sulfides, diaryl disulfides and asymmetric diaryl sulfides in good yields.
A new odorless one-pot synthesis of thioesters and selenoesters promoted by Rongalite
Dan, Weixing,Deng, Hongjuan,Chen, Jiuxi,Liu, Miaochang,Ding, Jinchang,Wu, Huayue
experimental part, p. 7384 - 7388 (2010/10/02)
Rongalite promotes cleavage of diaryl disulfides generating chalcogenolate anions that then undergo facile acylation with anhydrides in the presence of CsF to afford thioesters (3) with good to excellent yields. By using the present protocol, 5-arylthio-5-oxopentanoic acid (4) can be facilely prepared. The important features of the methodology are broad substrate scope, simple operation, and no requirement for metal catalysts. It is noteworthy that acylations of diphenyl diselane with anhydrides are also conducted smoothly to afford selenoesters (5) in good yields under the standard conditions.
Air-stable titanocene bis(perfluorooctanesulfonate) as a new catalyst for acylation of alcohols, phenols, thiols, and amines under solvent-free condition
Qiu, Renhua,Zhang, Guoping,Ren, Xiaofang,Xu, Xinhua,Yang, Ronghua,Luo, Shenglian,Yin, Shuangfeng
experimental part, p. 1182 - 1188 (2010/06/13)
Air-stable titanocene bis(perfluorooctanesulfonate) [Cp2Ti(OSO2C8F17)2] that shows high Lewis acidity was prepared from Cp2TiCl2 and AgOSO2C8F17. The compound was characterized by different techniques, and examined as a catalyst for acylation reactions. It was found that using equimolar acetic anhydride as acetylating agent and under solvent-free condition, Cp2Ti(OSO2C8F17)2 exhibits high activity and selectivity in the acetylation of various alcohols, phenols, thiols, and amines. Also, good catalytic efficiency is observed in the acylation of 2-phenylethanol across various acylating reagents. The catalyst can be reused without loss of activity in a test of ten cycles. The Cp2Ti(OSO2C8F17)2 catalyst affords a simple, efficient and general method for the acylation of alcohols, phenols, thiols, and amines.
A simple, base-free preparation of S-aryl thioacetates as surrogates for aryl thiols
Van Den Hoogenband, Adri,Lange, Jos H. M.,Bronger, Raymond P. J.,Stoit, Axel R.,Terpstra, Jan Willem
experimental part, p. 6877 - 6881 (2011/03/18)
A mild method for the preparation of S-aryl thioacetates by hetero cross-coupling reactions of aryl bromides or aryl triflates with potassium thioacetate is described. The reaction proceeded smoothly in toluene at 110°C, mediated by catalytic Pd2(dba)3 in combination with CyPF-tBu as the ligand. Neither the presence of a base nor microwave conditions were required. The formed S-aryl thioacetate proved to be stable under flash chromatographic conditions and could be rapidly converted into the corresponding thiol under mildly basic conditions.
Magnesium bistrifluoromethanesulfonimide as a new and efficient acylation catalyst
Chakraborti, Asit K.,Shivani
, p. 5785 - 5788 (2007/10/03)
Magnesium bistrifluoromethanesulfonimide catalyzed the acetylation of phenols, alcohols, and thiols under solvent-free conditions at room temperature and in short times. Electron-deficient and sterically hindered phenols provided excellent yields. The catalyst was found to be general for acylation with other anhydrides, such as propionic, isobutyric, pivalic, chloroacetic, and benzoic anhydrides. The rate of acylation was influenced by the electronic and steric factors associated with the anhydride. The reaction with less electrophilic anhydrides (e.g., chloroacetic and benzoic anhydrides) required higher temperature (～80 °C). Chemoselective acetylation, pivalation, and benzoylation took place with acid-sensitive alcohols without any competitive dehydration/rearrangement.
Effect of modification of the electrophilic center on the α effect
Um, Ik-Hwan,Lee, Ji-Youn,Bae, Sun-Young,Buncel, Erwin
, p. 1365 - 1371 (2007/10/03)
We report on a nucleophilic study of esters R-C(=X)-Y-Ar in which the electrophilic center has been modified by replacing O by S in the leaving group or carbonyl center: 4-nitrophenyl acetate (1), S-4-nitrophenyl thioacetate (2), 4-nitrophenyl benzoate (3), and O-4-nitrophenyl thionobenzoate (4). The studies include O- and S- nucleophiles as well as α nucleophiles in H2O at 25.0 ± 0.1°C. The sulfur nucleophile (4-chlorothiophenoxide, 4-ClPhS-) exhibits significant enhanced reactivity for the reactions with thiol and thione esters 2 and 4 compared with their oxygen analogues 1 and 3. On the contrary, the common nucleophile OH- is much less reactive towards 2 and 4 compared with 1 and 3. The effect of changing both the electrophilic center and the nucleofugic center on the reactivity of the other oxygen nucleophiles is not so significant: 4-chlorophenoxide (4-ClPhO-) is four to six times more reactive in the reactions with thiol and thione esters 2 and 4 compared with their oxygen analogues 1 and 3. The α effects exhibited by butan-2,3-dione monoximate (Ox-) and HOO- are strongly dependent on the nature of the electrophilic center of the substrates, indicating that the difference in the ground-state solvation energy cannot be fully responsible for the α effect. Our results clearly emphasize the strong dependence of the α effect on the substrate structure, notably, the nature of the electrophilic center. The impact of change in the nucleofuge (1-→2) and the electrophilic center (3-→4) on reactivity indicates that anucleophiles will need to be "purpose built" for decontamination and nucleophilic degradation of specific biocides.
An improved, general procedure to S-aryl thiol esters: A new synthetic application of dry arenediazonium o-benzenedisulfonimides
Barbero, Margherita,Degani, Iacopo,Dughera, Stefano,Fochi, Rita
, p. 1225 - 1230 (2007/10/03)
The reaction between dry arenediazonium o-benzenedisulfonimides (1) and sodium thioacetate or thiobenzoate in anhydrous acetonitrile at room temperature is an efficient and safe procedure, of general validity, for the preparation of S-aryl thiol esters. The products can be easily purified and the yields are always very high. Of the 28 considered examples, the average yield of the S-aryl thioacetates (7) was 86% and that of the S-aryl thiobenzoates (8) 88%. It was possible to recover, in good amount and from all the reactions, o-benzenedisulfonimide (9), reusable for the preparation of salts 1.
