- Facile Synthesis of Thiolacetates from Trichloromethyl Compounds
-
A new method for the conversion of trichloromethyl compounds into the corresponding thiolacetates by treatment with sodium thiolacetate in the presence of thiolacetic acid is described. This transformation proceeds at room temperature in high yield when a strong electron-withdrawing substituent is attached to the trichloromethyl group.
- Romero-Ortega, Moises,Reyes, Horacio,Covarruvias-Zuniga, Adrian,Cruz, Raymundo,Avila-Zarraga, Jose Gustave
-
-
Read Online
- Compound embodiments that release H2S by reaction with a reactive compound and methods of making and using the same
-
Disclosed herein are embodiments of a donor compound that releases H2S by reacting with a reactive compound. The donor compound embodiments described herein can be used to deliver H2S to a subject or a sample and further can be used to administer therapeutic agents. The donor compound embodiments also can facilitate bioconjugation. Methods of making and using the donor compound embodiments also are disclosed.
- -
-
Page/Page column 39-41
(2021/08/04)
-
- Methanesulfonic anhydride-promoted sustainable synthesis of thioesters from feedstock acids and thiols
-
Abstract: An unprecedented metal-, halogen- and solvent-free, MSAA-promoted S-carbonylation of thiols with feedstock acids has been developed. This new transformation provides an efficient and atom-economic strategy for the synthesis of thioesters in a single operation from readily available and inexpensive starting materials. The reaction avoids the use of expensive and hazardous coupling reagents, bases and generates water as the only by-product, thus making this chemical synthetic process more viable, environment-friendly and contributing towards sustainable chemistry. Graphic abstract: [Figure not available: see fulltext.].
- Singh, Pallavi,Peddinti, Rama Krishna
-
-
- Naphthalimide derivatives containing benzyl-sulfur bond as cleavable photoinitiators for near-UV LED polymerization
-
Three naphthalimide aryl benzyl sulfide derivatives (NABSs) cleavable photoinitiators (PIs) containing benzyl-sulfur bonds were designed and prepared. The effect of the benzyl-sulfur moiety and substituents located on benzene ring of the benzyl group on p
- Gao, Yanjing,Hu, Xiuyuan,Jiang, Shengling,Sun, Fang,Yu, Jia
-
-
- Tropolonate salts as acyl-transfer catalysts under thermal and photochemical conditions: Reaction scope and mechanistic insights
-
Acyl-transfer catalysis is a frequently used tool to promote the formation of carboxylic acid derivatives, which are important synthetic precursors and target compounds in organic synthesis. However, there have been only a few structural motifs known to efficiently catalyze the acyl-transfer reaction. Herein, we introduce a different acyl-transfer catalytic paradigm based on the tropolone framework. We show that tropolonate salts, due to their strong nucleophilicity and photochemical activity, can promote the coupling reaction between alcohols and carboxylic acid anhydrides or chlorides to give products under thermal or blue light photochemical conditions. Kinetic studies and density functional theory calculations suggest interesting mechanistic insights for reactions promoted by this acyl-transfer catalytic system.
- Mai, Binh Khanh,Koenigs, Rene M.,Nguyen, Thanh Vinh,Lyons, Demelza J.M.,Empel, Claire,Pace, Domenic P.,Dinh, An H.
-
p. 12596 - 12606
(2020/11/18)
-
- Unsymmetrical Disulfides Synthesis via Cs2CO3-Catalyzed Three-Component Reaction in Water
-
An unsymmetrical disulfides synthesis by Cs2CO3-catalyzed three-component coupling reaction of thioacetate, sodium thiosulfate, and benzyl halide in water is described. The safe, stable, and non-toxic Na2S2O3 was invoked as the sulfur-source, successfully avoiding the odor generation in the process of S?S bond formation. A wide range of substrate suitability and appropriate functional group tolerance were observed for the transformation. Notably, the approach reported here was compatible with various biomolecules including glucose, coumarin, and quinolinone. (Figure presented.).
- Wang, Dungai,Gao, Yuanji,Tong, Yunli,Xiong, Mingteng,Liang, Xiao,Zhu, Heping,Pan, Yuanjiang
-
supporting information
p. 4991 - 4995
(2020/09/23)
-
- Air-Tolerant Direct Thiol Esterification with Carboxylic Acids Using Hydrosilane via Simple Inorganic Base Catalysis
-
Direct thioesterification of carboxylic acids with thiols using nontoxic activation agents is highly desirable. Herein, an efficient and practical protocol using safe and inexpensive industrial waste polymethylhydrosiloxane as the activation agent and K3PO4 with 18-crown-6 as a catalyst is described. Various functional groups on carboxylic acid and thiol substituents can be tolerated by the present system to afford thioesters in yields of 19-100%.
- Xuan, Maojie,Lu, Chunlei,Liu, Meina,Lin, Bo-Lin
-
p. 7694 - 7701
(2019/06/27)
-
- Fungicidal Activity of S-Esters of Thiocarboxylic Acids as Antimicrobial Additives to Petroleum Products
-
Abstract: A variety of aliphatic and aromatic S-esters of thiocarboxylic acids have been tested for antimicrobial activity. The relationship between the chemical structure of the compounds R1SC(O)R2 and their toxicity for microorganisms has been revealed, and the effect of various functional groups on the antimicrobial properties has been shown. The cooling lubricant IKhP-45E with S-aryl thioacetate additives has been tested. It has been shown that the additives used (0.25–0.5 wt %) inhibit the growth of all the studied microorganisms; however, their activity with respect to fungi is higher. The introduction of S-aryl thioacetates provides the resistance of these oils to microbiological deterioration to retain the physicochemical properties for a long period of time.
- Aliev,Belovezhets,Oparina
-
-
- 4-Imidazol-1-yl-butane-1-sulfonic acid ionic liquid: Synthesis, structural analysis, physical properties and catalytic application as dual solvent-catalyst
-
4-Imidazol-1-yl-butane-1-sulfonic acid (ImBu-SO3H) has been successfully synthetized and fully characterized by FT-IR and high-resolution NMR spectroscopy (1H, 13C). The “plausible” alternative structures of ImBu-SO3H were discussed on the basis of its NMR data. The ionic liquid showed interesting dual solvent-catalyst property, which was studied experimentally for the acetylation of a variety of functionalized alcohols, phenols, thiols, amines and α-tocopherol (α-CTP) as the most active form of vitamin E with acetic anhydride and which provided good yields within a short reaction time. ImBu-SO3H was successfully recycled by product extraction with an average recovered yield of 82% for 5 subsequent runs. The catalytic activity of the recycled ImBu-SO3H showed almost no loss even after five consecutive runs.
- Khaligh, Nader Ghaffari,Mihankhah, Taraneh,Johan, Mohd Rafie,Juan, Joon Ching
-
p. 866 - 878
(2019/07/12)
-
- Suitable for UV - LED light curing of the naphthalimide aryl benzyl [...] photoinitiator and preparation method and application
-
The invention discloses a suitable for UV - LED light curing of the naphthalimide aryl benzyl [...] photoinitiators, relates to a photosensitive polymer field, based on the existing light initiator in UV - LED under irradiation of light source caused by t
- -
-
Paragraph 0012; 0032; 0037
(2019/03/25)
-
- Nanolayered cobalt-molybdenum sulphides (Co-Mo-S) catalyse borrowing hydrogen C-S bond formation reactions of thiols or H2S with alcohols
-
Nanolayered cobalt-molybdenum sulphide (Co-Mo-S) materials have been established as excellent catalysts for C-S bond construction. These catalysts allow for the preparation of a broad range of thioethers in good to excellent yields from structurally diverse thiols and readily available primary as well as secondary alcohols. Chemoselectivity in the presence of sensitive groups such as double bonds, nitriles, carboxylic esters and halogens has been demonstrated. It is also shown that the reaction takes place through a hydrogen-autotransfer (borrowing hydrogen) mechanism that involves Co-Mo-S-mediated dehydrogenation and hydrogenation reactions. A novel catalytic protocol based on the thioetherification of alcohols with hydrogen sulphide (H2S) to furnish symmetrical thioethers has also been developed using these earth-abundant metal-based sulphide catalysts.
- Corma, Avelino,Sorribes, Iván
-
p. 3130 - 3142
(2019/03/13)
-
- Indium-Catalyzed Direct Conversion of Lactones into Thiolactones and Selenolactones in the Presence of Elemental Sulfur and Selenium
-
The direct conversion of lactones into thiolactones with elemental sulfur (S 8) catalyzed by InCl 3 /PhSiH 3 in a one-pot reaction is described. This catalytic system was successfully applied to the novel preparation of selenolactones from lactones and selenium.
- Sakai, Norio,Horikawa, Shuhei,Ogiwara, Yohei
-
p. 565 - 574
(2017/12/26)
-
- Efficient synthesis of organic thioacetates in water
-
Thioacetates as precursors of thiols are interesting starting points for synthesizing other organosulfur compounds. Herein, we propose a simple, efficient and fast method to obtain organic thioacetates using water as a solvent. Taking into account the great attention that has been paid toward environmentally friendly synthetic procedures in the past decades, we prove the role and the strength of the thioacetate anion as a nucleophile for nucleophilic displacement reactions in an aqueous medium. The reactions were carried out under pH control, to prevent the decomposition of the mesylate starting materials, using potassium carbonate as a safe and mild base. A simple work up allows products to be obtained with excellent yield and acceptable purity.
- Olivito,Costanzo,Di Gioia,Nardi,Oliverio,Procopio
-
supporting information
p. 7753 - 7759
(2018/11/02)
-
- Harnessing the catalytic behaviour of 1,1,1,3,3,3-hexafluoro-2-propanol (HFIP): An expeditious synthesis of thioesters
-
A novel, efficient, metal-, base- and acid-free straightforward protocol has been developed for the construction of useful thioesters. The immense catalytic potential of HFIP for promoting the thiocarbonylation of acyl halides and thiols is disclosed. HFIP was recovered with ease and reused for further reactions without any loss of reactivity. Both aryl and alkyl thiols bearing electron-donating and electron-withdrawing groups as well as aryl- and alkyl acyl halides worked well in this reaction. Inexpensive precursors, short reaction time, obviating workup, high atom economy, and gram-scale preparation are the significant features of the developed eco-friendly route for S-carbonylation of thiols.
- Singh, Pallavi,Peddinti, Rama Krishna
-
supporting information
p. 1875 - 1878
(2017/04/21)
-
- Doping of copper (I) oxide onto a solid support as a recyclable catalyst for acetylation of amines/alcohols/phenols and synthesis of trisubstituted imidazole
-
A study of copper-mediated C-heteroatom especially C-N and C-O bond formations using simpler methodologies has been carried out. In the present work, acetylation of various substrates such as amines, phenols and alcohols; synthesis of 2,4,5-trisubstituted imidazole is done using simple and easily available starting materials. Copper (I) oxide was synthesized in situ by the reduction of Fehling's solution with glucose followed by its anchoring onto different supports like silica, HAP, basic alumina and cellulose. Comparison and contrasts between the reactivity of copper (I) oxide supported onto different supports for these reactions are made. The reactivity of copper (I) oxide seems to be largely dependent on the nature of support and the most active catalyst for a particular reaction was further characterized by different spectroscopic techniques such as FTIR, XRD, TGA, XPS, SEM, TEM and AAS. The catalysts were found to be stable, easily recyclable without any significant loss in activity. Graphical abstract: Applications of solid supported copper (I) oxides (where solid support is silica, HAP, cellulose and basic alumina) are studied for various organic transformations with special emphasis on C-N and C-O bond formation reactions.[Figure not available: see fulltext.]
- Gupta, Manjulla,Gupta, Monika
-
p. 231 - 241
(2016/01/09)
-
- Highly efficient and recyclable acetylation of phenols and alcohols by nickel zirconium phosphate under solvent-free conditions
-
Nickel zirconium phosphate nanoparticles have been used as an efficient catalyst for the acetylation of a wide range of alcohols and phenols with acetic anhydride in good to excellent yields under solvent-free conditions. The steric and electronic properties of the different substrates had a significant influence on the reaction conditions required to achieve the acetylation. The catalyst used in the current study was characterized by inductively coupled plasma optical emission spectroscopy, X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, and transmission electron microscopy. This nanocatalyst could also be recovered and reused at least six times without any discernible decrease in its catalytic activity.
- Hajipour, Abdol Reza,Karimi, Hirbod,Kohi, Afshin
-
-
- Preparation and characterization of multi-walled carbon nanotubes (MWCNTs), functionalized with phosphonic acid (MWCNTs-C-PO3H2) and its application as a novel, efficient, heterogeneous, highly selective and reusable catalyst for acetylation of alcohols, phenols, aromatic amines, and thiols
-
A novel, efficient, heterogeneous, and reusable multi-walled carbon nanotubes (MWCNTs), functionalized with phosphonic acid (MWCNTs-C-PO 3H2) has been synthesized. The synthesized CNTs were characterized using some electron microscopic techniques such as scanning electron microscopy (SEM), atomic force microscopy (AFM), Energy dispersive X-ray spectroscopy (EDAX), and also some thermal and spectroscopic methods such as thermogravimetry (TG). The nitrogen adsorption behavior of the MWCNTs-C-PO3H2 catalyst was evaluated using the TG instrumentation system at 25°C. The catalyst was applied successfully for highly efficient and selective acetylation of alcohols, phenols, thiols and aromatic amines with acetic anhydride at room temperature under solvent-free conditions. The reusability of the catalyst was checked and the recovered catalyst was reused for five runs without significant loss in activity.
- Dehghani, Farzaneh,Sardarian, Ali Reza,Doroodmand, Mohammad Mehdi
-
p. 673 - 684
(2014/05/20)
-
- Rice husk: Introduction of a green, cheap and reusable catalyst for the protection of alcohols, phenols, amines and thiols
-
A mild, efficient and eco-friendly protocol for the chemoselective protection of benzylic and primary and less hindered secondary aliphatic alcohols and phenols as trimethylsilyl ethers and different types of amines as N-tert-butylcarbamates is developed using rice husk (RiH) as the catalyst. This reagent is also able to catalyze the acetylation of alcohols, phenols, thiols and amines with acetic anhydride. Easy work-up, relatively short reaction times, excellent yields and low cost, availability and reusability of the catalyst are the striking features of this methodology, which can be considered to be one of the best and general methods for the protection of alcohols, phenols, thiols and amines. In addition, the use of a green reagent in the above-mentioned reactions results in a reduction of environmental pollution and of the cost of the applied methods.
- Shirini, Farhad,Akbari-Dadamahaleh, Somayeh,Mohammad-Khah, Ali,Aliakbar, Ali-Reza
-
p. 164 - 170
(2014/03/21)
-
- Processes for forming amide bonds and compositions related thereto
-
The disclosure relates to methods for producing amide bonds and reagents related thereto. In some embodiments, the disclosure relates to methods of producing an amide comprising mixing an O-silylated thionoester and an amine under conditions such that an amide is formed. In another embodiment, the disclosure relates to mixing a thiolacid, a silylating agent, and an amine under conditions such that an amide is formed.
- -
-
Page/Page column 32
(2015/01/07)
-
- Mild Ti-mediated transformation of t-butyl thio-ethers into thio-acetates
-
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
- Pijper, Thomas C.,Robertus, Jort,Browne, Wesley R.,Feringa, Ben L.
-
supporting information
p. 265 - 268
(2015/01/16)
-
- Poly(N-vinylimidazole) as an efficient catalyst for acetylation of alcohols, phenols, thiols and amines under solvent-free conditions
-
Poly(N-vinylimidazole) is able to promote instantaneous quantitative acetylation of a variety of functionalized alcohols, phenols, thiols and amines with acetic anhydride at room temperature under solvent-free conditions. This new method consistently has excellent yields and the catalyst can be reused and recovered several times. Furthermore, the reaction can even be carried out on a larger scale. The Royal Society of Chemistry.
- Khaligh, Nader Ghaffari
-
-
- A succinimide-N-sulfonic acid catalyst for acetylation reactions in absence of a solvent
-
A small amount of succinimide-N-sulfonic acid efficiently catalyzed the acetylation of a variety alcohols, phenols, thiols, amines and aldehydes with acetic anhydride at room temperature under solvent free conditions. This catalyst has the advantages of excellent yields and short reaction times and the reaction can be carried out on a large scale, which makes it potentially useful for industrial applications.
- Shirini, Farhad,Khaligh, Nader Ghaffari
-
p. 695 - 703
(2013/08/25)
-
- In situ generated Ph3P(OAc)2as a novel reagent for the efficient acetylation of alcohols and thiols at room temperature
-
Ph3P, Br2, and ammonium acetate are used for the in situ generation of Ph3P(OAc)2, which was characterized by different NMR techniques. The Ph3P(OAc)2generated was used as a novel and efficient reagent for the acetylation of alcohols and thiols in acetonitrile at room temperature under homogeneous conditions. This reaction was also performed under heterogeneous conditions using 1,3,2,4- diazadiphosphetidine as an easily prepared, stable, and heterogeneous P(III) compound.
- Iranpoor, Nasser,Firouzabadi, Habib,Elham, Etemadi Davan
-
p. 1813 - 1816
(2013/04/24)
-
- Acyl iodides in organic synthesis. Reaction of acetyl iodide with Dialkyl sulfides and disulfides
-
Reactions of acetyl iodide with dialkyl and dialkenyl sulfides RSR (R = Et, Bu, CH2=CH, CH2=CHCH2) and with disulfides RSSR (R = Pr, C6H13, PhCH2) were studied. Dialkyl sulfides reacted with MeCOI to give the corresponding alkyl ethanethioates and alkyl iodides as a result of cleavage of the S-C bond. The reactions of acetyl iodide with divinyl and diallyl sulfides involved addition across the double bond and subsequent polymerization of 1-alkenylsulfanyl-2(3)- iodoalkyl methyl ketones. Dialkyl disulfides RSSR (R = Pr, C6H 13) and dibenzyl disulfide reacted with acetyl iodide via cleavage of the S-S bond to produce the corresponding ethanethioates and organylsulfenyl iodides. The latter underwent disproportionation to form the initial disulfide and molecular iodine.
- Vlasova,Grigor'Eva,Voronkov
-
-
- Convenient synthesis of alkyl thioacetate from alkyl halide using a polymer-supported sodium thioacetate
-
Alkyl halides are efficiently converted to their corresponding S-alkyl thioacetates under mild and nonaqueous conditions, using polymer-supported sodium thioacetate as a new polymeric reagent at room temperature in high yields and purity. The spent polymeric reagent can be removed quantitatively by filtration and pure products can be obtained by evaporation of the solvent. The spent polymeric reagent can be regenerated and reused several times without its activity changing appreciably. Iranian Chemical Society 2012.
- Zarchi, Mohammad Ali Karimi,Nejabat, Mojgan
-
p. 767 - 774
(2013/02/23)
-
- Platonic hexahedron composed of six organic faces with an inscribed Au cluster
-
The structures of nanomaterials determine their individual properties and the suprastructures they can form. Introducing anisotropic shapes and/or interaction sites to isotropic nanoparticles has been proposed to extend the functionality and possible suprastructure motifs. Because of symmetric anisotropy, Platonic solids with regular polygon faces are one of the most promising nanoscale structures. Introduction of Platonic solid anisotropy to isotropic nanomaterials would expand the functionality and range of possible suprastructure motifs. Here, we demonstrate a novel strategy to obtain nano-Platonic solids through the face coordination of square porphyrins on an inscribed Au sphere with adequate size. The face coordination of the multidentate porphyrin derivatives, with four acetylthio groups facing the same direction, on the Au cluster encased the Au cluster in a Platonic hexahedron with six porphyrin faces. Transmission electron microscopy, mass spectrometry, elemental analysis, and scanning tunnelling microscopy were used to confirm the formation of the nano-Platonic hexahedron.
- Sakamoto, Masanori,Tanaka, Daisuke,Tsunoyama, Hironori,Tsukuda, Tatsuya,Minagawa, Yoshihiro,Majima, Yutaka,Teranishi, Toshiharu
-
p. 816 - 819
(2012/03/07)
-
- Poly-(N,N′-dibromo-N-ethyl-benzene-1,3-disulfonamide) and N,N,N′,N′- tetrabromobenzene-1,3-disulfonamide as highly efficient catalysts, and (AC2O/SIO2) as a heterogeneous system for the acetylation of alcohols, amines, and thiols under microwave irradiation
-
Chemical Equation Presented Poly-(N,N′-dibromo-N-ethyl-benzene-1,3- disulfonamide) (PBBS) and N,N,N′,N′-tetrabromobenzene-1,3- disulfonamide (TBBDA) are good activators and catalytic reagents for the acetylation of alcohols, amines, and thiols. The presented method has the advantages of mild conditions, chemoselectivity, and good to high yields, and uses noncorrosive, inexpensive, recyclable, and environmentally friendly catalysts. We have also demonstrated that combining SiO2 with microwave energy provides an efficient, fast, convenient, and easy workup procedure for the synthesis of mono- and disubstituted acetates, acetamides, and thioacetamides. Copyright Taylor & Francis Group, LLC.
- Veisi, Hojat,Ghorbani-Vaghei, Ramin,Eskandari, Hosna,Hemmati, Saba,Rezaei, Ardashir,Hajinazari, Somaye,Far, Mohammad Raoof Heidari,Entezari, Azam
-
experimental part
p. 213 - 219
(2011/04/24)
-
- Palladium-catalyzed cross-coupling of benzyl thioacetates and aryl halides
-
A method for preparing benzyl aryl thioethers utilizing an in situ deprotection of benzyl thioacetates as an alternative to free thiols as starting materials has been developed and optimized. Good to excellent yields of diverse benzyl aryl thioethers are
- Wager, Krista M.,Daniels, Matthew H.
-
supporting information; experimental part
p. 4052 - 4055
(2011/10/02)
-
- N,N'-Diiodo-N,N'-1,2-ethanediylbis(p-toluenesulfonamide) as an efficient catalyst for acetylation of alcohols, phenols, amines, and thiols under solvent-free conditions
-
N,N'-Diiodo-N,N'-1,2-ethanediylbis(p-toluenesulfonamide) (NIBTS) is a highly efficient catalyst for the acetylation of alcohols, phenols, amines, and thiols under solvent-free conditions. Primary, secondary, tertiary alcohols; phenols; amines; and thiols can be easily acetylated in good to excellent yields at 80 C. Copyright Taylor & Francis Group, LLC.
- Ghorbani-Vaghei, Ramin,Toghraei-Semiromi, Zahra
-
experimental part
p. 1701 - 1707
(2010/09/17)
-
- Air-stable titanocene bis(perfluorooctanesulfonate) as a new catalyst for acylation of alcohols, phenols, thiols, and amines under solvent-free condition
-
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.
- Qiu, Renhua,Zhang, Guoping,Ren, Xiaofang,Xu, Xinhua,Yang, Ronghua,Luo, Shenglian,Yin, Shuangfeng
-
experimental part
p. 1182 - 1188
(2010/06/13)
-
- Solvent-free acetylation of thiols under catalysis of MgBr 2·OEt2
-
Solvent-free protection of aromatic and aliphatic thiols with acetic anhydride was performed at room temperature under trace quantities of magnesium bromide ethyl etherate, affording rapid formation of various thiol esters in excellent yields. Copyright Taylor & Francis Group, LLC.
- Mojtahedi, Mohammad M.,Abaee, M. Saeed,Javadpour, Mashal
-
experimental part
p. 2362 - 2365
(2011/02/22)
-
- Probing the mechanism of electron capture and electron transfer dissociation using tags with variable electron affinity
-
Electron capture dissociation (ECD) and electron transfer dissociation (ETD) of doubly protonated electron affinity (EA)-tuned peptides were studied to further illuminate the mechanism of these processes. The model peptide FQpSEEQQQTEDELQDK, containing a
- Sohn, Chang Ho,Chung, Cheol K.,Yin, Sheng,Ramachandran, Prasanna,Loo, Joseph A.,Beauchamp, J. L.
-
experimental part
p. 5444 - 5459
(2009/09/25)
-
- Simple and efficient method for acetylation of alcohols, phenols, amines, and thiols using anhydrous NiCl2 under solvent-free conditions
-
Solvent-free acetylation of alcohols, phenols, amines, and thiols with acetic anhydride (Ac2O) in the presence of 0.1mol% (13mg) anhydrous NiCl2, an inexpensive and easily available catalyst, is described. Excellent yields, short reaction time, and mild reaction conditions are important features of this method.
- Meshram, Gangadhar,Patil, Vishvanath D.
-
experimental part
p. 4384 - 4395
(2010/04/29)
-
- A novel method for the synthesis of thioacetates using benzyltriethyl- ammonium tetrathiomolybdate and acetic anhydride
-
Herein we report a simple and efficient methodology for the synthesis of thioacetates using benzyltriethylammonium tetrathiomolybdate and acetic anhydride as the key reagents, starting from alkyl halides in a multistep, tandem reaction process. Its application in the synthesis of orthogonally protected cysteine and anomeric β-thioglycosides has also been demonstrated.
- Nasir, Baig R. B.,Sai, Sudhir V.,Srinivasan, Chandrasekaran
-
scheme or table
p. 2684 - 2688
(2009/04/16)
-
- o-benzenedisulfonimide as a soft, efficient, and recyclable catalyst for the acylation of alcohols, phenols, and thiols under solvent-free conditions: Advantages and limitations
-
o-Benzenedisulfonimide turns out to be a highly efficient Bransted acid catalyst for the acylation of a number of alcohols, phenols, and thiols under a metal- and solvent-free procedure; reaction conditions are mild and yields very good. After the workup, the catalyst can be easily recovered and purified, ready to be reused, with economic and ecological advantages. Georg Thieme Verlag Stuttgart · New York.
- Barbero, Margherita,Cadamuro, Silvano,Dughera, Stefano,Venturello, Paolo
-
experimental part
p. 3625 - 3632
(2009/07/04)
-
- Piperylene sulfone: A labile and recyclable DMSO substitute
-
The properties and uses of piperylene sulfone as a new, recyclable dipolar, aprotic solvent for conducting organic reactions are presented. The Royal Society of Chemistry.
- Vinci,Donaldson,Hallett,John,Pollet,Thomas,Grilly,Jessop,Liotta,Eckert
-
p. 1427 - 1429
(2008/02/03)
-
- A direct aldol addition of simple thioesters employing soft enolization
-
Simple thioesters undergo direct aldol addition to aldehydes in the presence of magnesium bromide-diethyl ether and N,N-diisopropylethylamine using untreated, reagent grade dichloromethane under atmospheric conditions. The reactions proceed extremely rapi
- Zhou, Guoqiang,Yost, Julianne M.,Coltart, Don M.
-
p. 478 - 482
(2007/12/27)
-
- Mild and efficient methods for the conversion of benzylic bromides to benzylic thiols
-
Very mild and efficient methods are established for the conversion of the benzylic bromides at room temperature to their corresponding benzylic thiols with high yields (94-99%) in 1 h under N2.
- Han, Chien-Chung,Balakumar
-
p. 8255 - 8258
(2007/10/03)
-
- A facile and efficient direct aldol addition of simple thioesters
-
Simple thioesters undergo direct aldol addition to aldehydes in the presence of MgBr2·OEt2 and i-Pr2NEt using untreated, reagent-grade CH2Cl2 under atmospheric conditions. The reactions proceed extrem
- Yost, Julianne M.,Zhou, Guoqiang,Coltart, Don M.
-
p. 1503 - 1506
(2007/10/03)
-
- Magnesium bistrifluoromethanesulfonimide as a new and efficient acylation catalyst
-
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.
- Chakraborti, Asit K.,Shivani
-
p. 5785 - 5788
(2007/10/03)
-
- Practical preparation of esters and thioacetates from alkyl halides and carboxylates or thioacetate catalyzed by PEG400 without solvent
-
Carboxylic esters and thioacetates were conveniently prepared in good to excellent yields under mild conditions by the reaction of alkyl halides with sodium carboxylates or sodium thioacetate catalyzed by PEG400 in the absence of solvents. Copyright Taylor & Francis Group, LLC.
- Cao, Yu-Qing,Wu, Guo-Qiang,Li, Ya-Bin,Dai, Zhi,Chen, Bao-Hua
-
p. 3353 - 3358
(2007/10/03)
-
- KF/Al2O3 catalysed synthesis of thiol esters from N-acylphthalimides and thiols
-
A new method for the preparation of thiol esters from N-acylphthalimides and thiols in the presence of KF/Al2O3 is introduced.
- Movassagh, Barahman,Zakinezhad, Yousef
-
p. 369 - 370
(2007/10/03)
-
- Nucleophilic acyl substitutions of anhydrides with protic nucleophiles catalyzed by amphoteric, oxomolybdenum species
-
(Chemical Equation Presented) Among six different group VIb oxometallic species examined, dioxomolybdenum dichloride and oxomolybdenum tetrachloride were the most efficient catalysts to facilitate nucleophilic acyl substitution (NAS) of anhydrides with a myriad array of alcohols, amines, and thiols in high yields and high chemoselectivity. In contrast to the well-recognized redox chemical behaviors associated with oxomolybdenum(VI) species, the catalytic NAS was unprecedented and tolerates virtually all kinds of functional groups. By using benzoic anhydride as a mediator for in situ generation of an incipient mixed anhydride-MoO2Cl2 adduct with a given functional alkanoic acid, one can achieve oleate, dipeptide, diphenylmethyl, N-Fmoc-α-amino, pyruvic, and tert-butylthio ester, N-tert-butylamide, and trityl methacrylate syntheses with appropriate protic nucleophiles. The amphoteric character of the Mo=O unit in oxomolybdenum chlorides was found to be responsible for the catalytic NAS profile as supported by a control NAS reaction of using an authentic adduct-MoOCl2(O2-CBu t)2 between pivalic anhydride and MoO2Cl 2 as the catalyst.
- Chen, Chien-Tien,Kuo, Jen-Huang,Pawar, Vijay D.,Munot, Yogesh S.,Weng, Shieu-Shien,Ku, Cheng-Hsiu,Liu, Cheng-Yuan
-
p. 1188 - 1197
(2007/10/03)
-
- A facile and practical method for the preparation of thioacetates from alkyl halides and sodium thioacetate catalysed by PEG400
-
Thioacetates are conveniently prepared in high yields under mild conditions by the reaction of alkyl halides and sodium thioacetate, prepared in situ from thioacetic acid and sodium carbonate, catalysed by PEG400 at room temperature.
- Cao, Yu-Qing,Du, Yun-Fei,Chen, Bao-Hua,Dai, Zhi
-
p. 762 - 763
(2007/10/03)
-
- Copper(II) Tetrafluoroborate-Catalyzed Acetylation of Phenols, Thiols, Alcohols, and Amines
-
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. The reaction is influenced by the steric and electronic factors associated with the substrate as well as the anhydride. Acetylation of a sterically hindered substrate requires excess of anhydride and longer time. Acylation with less electrophilic anhydrides affords poor to moderate yields.
- Chakraborti, Asit K.,Gulhane, Rajesh,Shivani
-
p. 111 - 115
(2007/10/03)
-
- Zirconiuni(IV) chloride as a new, highly efficient, and reusable catalyst for acetylation of phenols, thiols, amines, and alcohols under solvent-free conditions
-
Zirconium(IV) chloride has been found to be a new, highly efficient, and reusable catalyst for acetylation of structurally diverse phenols, thiols, amines, and alcohols under solvent-free condtions. Acetylation of sterically hindered and electron deficient phenols is achieved in excellent yields with stoichiometric amounts of Ac2O at room temperature. Acid-sensitive alcohols undergo acetylation with excellent chemoselectivity without competitive side reactions such as dehydration or rearrangement. The mild Lewis acid property of the catalyst enables the acetylation to be carried out with optically active substrates without any detrimental effect on the optical purity.
- Chakraborti, Asit K.,Gulhane, Rajesh
-
p. 627 - 630
(2007/10/03)
-
- A Convenient Synthesis of Thioacetates and Thiobenzoates Using Silica-Gel Supported Potassium Thioacetate
-
A simple and efficient procedure has been developed for the synthesis of thioesters by a reaction of alkyl halides with silica-gel supported potassium thioacetate or thiobenzoate under mild conditions.
- Aoyama, Tadashi,Takido, Toshio,Kodomari, Mitsuo
-
p. 3817 - 3824
(2007/10/03)
-
- Bismuth Oxide Perchlorate as a Highly Efficient Catalyst for Heteroatom Acylation under Solvent-Free Conditions
-
Bismuth oxide perchlorate efficiently catalyzes the acetylation of structurally diverse phenols, alcohols, thiols, and amines under solvent free conditions. Sterically hindered and electron deficient phenols are acetylated in excellent yields with stoichiometric amounts of Ac2O at room temperature. Acylation of acid-sensitive alcohols is carried out efficiently without competitive side reactions. Optically active substrates are acetylated without any detrimental effect on the optical purity.
- Chakraborti, Asit K.,Gulhane, Rajesh,Shivani
-
p. 1805 - 1808
(2007/10/03)
-
- Perchloric acid adsorbed on silica gel as a new, highly efficient, and versatile catalyst for acetylation of phenols, thiols, alcohols, and amines
-
Perchloric acid adsorbed on silica gel efficiently catalyses acetylation of structurally diverse phenols, alcohols, thiols, and amines under solvent free conditions.
- Chakraborti, Asit K.,Gulhane, Rajesh
-
p. 1896 - 1897
(2007/10/03)
-
- Aluminium dodecatungstophosphate (AlPW12O40) as a highly efficient catalyst for the selective acetylation of -OH, -SH and -NH2 functional groups in the absence of solvent at room temperature
-
AlPW12O40 was found to be an effective catalyst for the selective acetylation of alcohols, thiols, and amines in the absence of solvent at room temperature.
- Firouzabadi, Habib,Iranpoor, Nasser,Nowrouzi, Farhad,Amani, Kamal
-
p. 764 - 765
(2007/10/03)
-
- Fluoroboric acid adsorbed on silica gel as a new and efficient catalyst for acylation of phenols, thiols, alcohols, and amines
-
Fluoroboric acid supported on silica gel efficiently catalyzes acylation of structurally diverse phenols, alcohols, thiols, and amines under solvent free conditions. Acid-sensitive alcohols are smoothly acylated without competitive side reactions.
- Chakraborti, Asit K.,Gulhane, Rajesh
-
p. 3521 - 3525
(2007/10/03)
-