- Substituted o-Aminophenols as Redox-Mediators in the Thiol Oxidation to Unsymmetrical Disulfides
-
A number of substituted o-aminophenols has been investigated as redox mediators of the thiol oxidation to disulfides. The electrooxidation of o-aminophenols leads to the corresponding o-iminobenzoquinones. These compounds react with thiols in the solution with a formation of disulfides. It was established that the use of 4,6-di-tert-butyl-2-(tert-butylamino)phenol as a redox mediator can reduce the overpotential of the thiol oxidation by 0.2-1.4 V depending on the nature of the coupling thiols. The unsymmetrical disulfides with alkyl, aryl, and heteroaryl substituents were obtained as the result of the indirect electrosynthesis.
- Berberova, Nadezhda T.,Burmistrova, Daria A.,Galustyan, Andrey,Smolyaninov, Ivan V.
-
-
- Condensation of Propan-2-one with Formaldehyde and Propane-2-thiol
-
Abstract: Three-component condensation of propan-2-one with formaldehyde and propane-2-thiol in the presence of sodium hydroxide afforded 3-{[(propan-2-yl)sulfanyl)]methyl}but-3-en-2-one or 4-[(propan-2-yl)sulfanyl]-3-{[(propan-2-yl)sulfanyl]methyl}butan-
- Baeva, L. A.,Biktasheva, L. F.,Nugumanov, R. M.,Safiullin, R. L.
-
p. 567 - 571
(2020/07/02)
-
- A rapid, efficient and green procedure for transformation of alkyl halides/ tosylates to organochalcogens in water
-
A one-pot and efficient synthesis of dialkyl dichalcogenides (S, Se) in aqueous media under catalyst-free conditions using benzylic, allylic and primary halides with elemental sulfur and selenium has been developed. Also, this procedure was extended to preparation of trisulfides and triselenides from secondary and tertiary halides in same condition. In all cases, products can be obtained in good to excellent yield in short reactions time.
- Soleiman-Beigi, Mohammad,Yavari, Issa,Sadeghizadeh, Fatemeh
-
supporting information
p. 41 - 44
(2017/09/25)
-
- Dicationic Thiolate-Bridged Diruthenium Complexes for Catalytic Oxidation of Molecular Dihydrogen
-
Dicationic thiolate-bridged diruthenium complexes bearing sterically bulky alkane substituents on the thiolate ligands such as [Cp?Ru(μ-SiPr)2Ru(OH2)Cp?](OTf)2 have been found to work as effective catalysts toward oxidation of molecular dihydrogen into protons and electrons in protic solvents such as water and methanol. DFT calculations indicate that the sterically bulky alkane substituent in the complex plays an important role in facilitating the reaction step of the coordination of molecular dihydrogen.
- Yuki, Masahiro,Sakata, Ken,Nakajima, Kazunari,Kikuchi, Syoma,Sekine, Shinobu,Kawai, Hiroyuki,Nishibayashi, Yoshiaki
-
supporting information
p. 4499 - 4506
(2017/12/05)
-
- Thiol Reactivity toward Atomic Oxygen Generated during the Photodeoxygenation of Dibenzothiophene S-Oxide
-
Aromatic heterocyclic oxides, such as dibenzothiophene S-oxide (DBTO), have been suggested to release ground state atomic oxygen [O(3P)] upon irradiation, and as such, they have been used to create a condensed phase reactivity profile for O(3P). However, thiols, which are highly reactive with O(3P) in the gas phase, were not previously investigated. An earlier study of O(3P) with proteins in solution indicated a preference for thiols. A further investigation of the apparent thiophilicity provided the subject for this study. DBTO was employed as a putative O(3P)-precursor. However, the effective rate of O(3P) formation was found to be dependent on reactant concentrations in certain cases. All reactants were found to increase the rate of deoxygenation to some extent, but in the presence of reactants containing an alcohol linked to a reactive functional group, deoxygenation occurred substantially more rapidly. The rate enhancement was quantified and attributed to the reaction of activated O atom within the solvent cage prior to escape into the bulk solution. Through competition experiments, the relative rate constants of O(3P) with thiols and other functional groups were found. A small preference for primary thiols was observed over other thiols, sulfides, and alkenes. A much larger preference was observed for thiols, sulfides, and alkenes over aromatic groups. In summary, DBTO was successfully used as an O(3P)-precursor, and the thiophilicity of O(3P) was confirmed and quantified.
- Omlid, Sara M.,Zhang, Miao,Isor, Ankita,McCulla, Ryan D.
-
p. 13333 - 13341
(2017/12/15)
-
- Europhtal (8020) efficiently catalyzes the aerobic oxidation of in situ generated thiols to symmetric disulfides (disulfanes)
-
Efficient, odorless and scalable synthetic protocols have been introduced for the preparation of symmetric alkyl disulfides by treatment of the corresponding organic halides with thiourea and NaHCO3in the presence of commercially available Europhtal catalyst (8020) in both H2O and poly ethylene glycol (PEG-200) media at 80–90 °C. Structurally diverse primary, secondary, allylic and benzylic halides were examined successfully whereas, the result with tert-butyl bromide was not satisfactory. Also, another procedure has been introduced for achieving symmetric aryl disulfides in high yields by reacting aryl halides, thiourea and NaHCO3in PEG-200 at 115–120 °C using CuI along with Europhtal catalysts. The results showed that the aerobic oxidation of in situ generated thiols proceeded efficiently in the presence of Europhtal catalyst giving the symmetric disulfide without contamination by symmetric sulfide side-product.
- Abbasi, Mohammad,Sabet, Askar,Sabet, Askar
-
-
- A two in one approach: Renewable support and enhanced catalysis for sweetening using chicken feather bound cobalt(II) phthalocyanine under alkali free environment
-
Poultry waste chicken feathers, an inexpensive and abundantly available material has been used as a renewable support for immobilizing a cobalt phthalocyanine catalyst. The synthesized heterogeneous cobalt(ii) phthalocyanine catalyst was used for the aerobic oxidation of mercaptans to the corresponding disulfides using ultrasonic irradiation under alkali free conditions. The significantly higher catalytic activity of the heterogeneous catalyst as compared to a homogeneous one can be attributed to the synergistic effect of the support matrix. In addition, the catalyst could easily be recovered and recycled for several runs without loss of activity, which makes the process greener and more cost-effective.
- Chauhan, Deepak K.,Patnam, Padma L.,Ganguly, Sudip K.,Jain, Suman L.
-
p. 51983 - 51988
(2016/06/13)
-
- The synthesis of symmetrical disulfides by reacting organic halides with Na2S2O3·5H2O in DMSO
-
A one-pot, and scalable method to prepare symmetric disulfides from their corresponding primary, secondary, allylic, and benzylic halides has been developed. In this method, a disulfide is synthesized by reacting an alkyl halide with Na2S2O3·5H2O at 60-70 °C in DMSO.
- Abbasi, Mohammad,Mohammadizadeh, Mohammad Reza,Saeedi, Narges
-
supporting information
p. 89 - 92
(2016/01/12)
-
- One-pot conversion of alkyl halides to organic disulfides (disulfanes) using thiourea and hexamethyldisilazane (HMDS) in DMSO
-
A practical method to synthesize symmetric disulfides from alkyl halides has been developed. Using this procedure primary, secondary, benzylic and allylic disulfides were prepared by treating the corresponding alkyl halides with thiourea and HMDS in DMSO at 50 °C within 10-24 h in high yields.
- Abbasi, Mohammad,Jabbari, Arida
-
-
- Magnetic Fe3O4@MgAl-LDH composite grafted with cobalt phthalocyanine as an efficient heterogeneous catalyst for the oxidation of mercaptans
-
Magnetically separable layered double hydroxide MgAl-LDH@Fe3O4 composite supported cobalt phthalocyanine catalyst was synthesized and used for the aerobic oxidation of mercaptans to corresponding disulfides under alkali free conditions. The catalyst exhibited excellent activity for the oxidation of mercaptans using molecular oxygen as an oxidant which can be effectively recovered by using an external magnetic field. In addition, the covalent immobilization of cobalt phthalocyanine to MgAl-LDH@Fe3O4 support prevents the leaching of the catalyst and improves its activity and stability.
- Kumar, Pawan,Gill, Kareena,Kumar, Sunil,Ganguly, Sudip K.,Jain, Suman L.
-
-
- Haloacid/dimethyl sulfoxide-catalyzed synthesis of symmetrical disulfides by oxidation of thiols
-
A novel method is developed for the oxidation of thiols to the corresponding disulfides using 20 mol % haloacid (HBr or HI) in combination with dimethyl sulfoxide. A tentative mechanism is proposed for the oxidation. In addition to the advantages of cost-effectiveness, simple processes, and broad functional group tolerance, the exclusive formation of disulfides is the principle reward of this methodology while compared to known methods that further oxidize disulfides to S-oxides and other byproducts.
- Natarajan, Palani,Sharma, Himani,Kaur, Mandeep,Sharma, Pooja
-
supporting information
p. 5578 - 5582
(2015/09/21)
-
- A mild and efficient method for the conversion of aldehydes into nitriles and thiols into disulfides using an ionic liquid oxidant
-
A simple, mild and high yielding method for the conversion of various aldehydes to nitriles has been developed using an ionic liquid reagent, hexamethylene bis(N-methylimidazolium) bis(dichloroiodate) (HMBMIBDCI), in combination with aqueous ammonia in CH3CN at room temperature. Moreover, the treatment of aromatic and aliphatic thiols with HMBMIBDCI resulted in the corresponding disulfides in solvent-free condition at room temperature.
- Hosseinzadeh, Rahman,Golchoubian, Hamid,Nouzarian, Mahboobe
-
p. 4713 - 4725
(2015/06/30)
-
- One-pot synthesis of organic disulfides (disulfanes) from alkyl halides using sodium sulfide trihydrate and hexachloroethane or carbon tetrachloride in the poly(ethylene glycol) (PEG-200)
-
Abstract Symmetric disulfides are produced by treating their corresponding organic halides including benzylic, allylic, primary and secondary halides with Na2S·3H2O and C2Cl6 or CCl4 in PEG-200 at room temperature in high yields.
- Abbasi, Mohammad,Mohammadizadeh, Mohammad Reza,Moosavi, Hekmat,Saeedi, Narges
-
p. 1185 - 1190
(2015/03/31)
-
- Ultrasound-Accelerated Synthesis of Asymmetrical Thiosulfonate S-Esters by Base-Promoted Reaction of Sulfonyl Chlorides with Thiols
-
Amberlyst A-26, Mg-Al hydrotalcite, potassium fluoride absorbed on alumina, triethylamine and pyridine have been tested as base catalysts and reagents for the reaction of sulfonyl chlorides with thiols to prepare thiosulfonate S-esters. The reactions were performed under solvent-free conditions or with a minimum amount of solvent assisted by magnetic stirring, ultrasound irradiation and microwave irradiation. Ultrasound irradiation has good effects on the synthesis of sterically hindered thiosulfonate S-esters in solvent-free media as well as in a minimum amount of anhydrous diethyl ether.
- Pham, Hien Thi,Nguyen, Ngoc-Lan Thi,Duus, Fritz,Luu, Thi Xuan Thi
-
p. 1934 - 1941
(2015/12/12)
-
- Direct synthesis of disulfides from alkyl halides using thiourea and CCl4 in glycerol
-
Abstract Dialkyl disulfides were obtained on the basis of the reaction of alkyl halides and thiourea in the presence of CCl4 and Et3N. This procedure enables the odorless and one-pot synthesis of disulfides by employing cheap, easy-to-handle and readily available reagents and substrates in wet glycerol.
- Abbasi, Mohammad,Khalili, Dariush
-
p. 1425 - 1430
(2015/06/22)
-
- Graphene Oxide-Assisted One-Pot and Odorless Synthesis of Symmetrical Disulfides Using Primary and Secondary Alkyl Halides (Tosylates) and Thiourea as Sulfur Source Reagent
-
Graphene oxide is described as a heterogeneous oxidant for the synthesis of symmetrical disulfides through the in situ generation of thiols from primary and secondary alkyl halides (tosylates) and thiourea in wet acetonitrile. A variety of alkyl halides and alkyl tosylates can be converted to corresponding disulfides in good to excellent yields. This strategy is free of foul-smelling thiols.
- Khalili, Dariush
-
p. 1727 - 1734
(2015/12/12)
-
- Marine bacteria from the Roseobacter clade produce sulfur volatiles via amino acid and dimethylsulfoniopropionate catabolism
-
Dimethylsulfoniopropionate (DMSP) is a versatile sulfur source for the production of sulfur-containing secondary metabolites by marine bacteria from the Roseobacter clade. 34S-labelled DMSP and cysteine, and several DMSP derivatives with modified S-alkyl groups were synthesised and used in feeding experiments that gave insights into the biosynthesis of sulfur volatiles from these bacteria. the Partner Organisations 2014.
- Brock, Nelson L.,Menke, Markus,Klapschinski, Tim A.,Dickschat, Jeroen S.
-
supporting information
p. 4318 - 4323
(2014/06/23)
-
- One-pot efficient synthesis of disulfides from alkyl halides and alkyl tosylates using thiourea and elemental sulfur without contamination by higher polysulfides
-
An efficient and odorless synthesis of disulfides from alkyl halides using thiourea and elemental sulfur in the presence of sodium carbonate in wet polyethylene glycol (PEG 200) at 40 C without contamination by higher polysulfides has been developed. This procedure was then extended to preparation of disulfides from alkyl tosylates at 70 C.
- Abbasi, Mohammad,Mohammadizadeh, Mohammad Reza,Taghavi, Zeinab Khatoon
-
p. 201 - 205
(2013/07/26)
-
- Microwave assisted oxidative coupling of thiols to symmetrical disulfides with tripropylammonium fluorochromate(VI) (TPAFC)
-
Tripropylammonium fluorochromate(VI) (TPAFC) is an efficient and novel reagent, which can be prepared easily and oxidizes thiols to the corresponding disulfides, quickly. The reactions are performed cleanly and are controlled to stop at the disulfide stage, without over-oxidation or side products. Coupling of thiols to their corresponding disulfides, was studied in solution at room temperature and under conditions using a minimal amount of solvent under microwave irradiation. The easy procedure, simple work-up, short reaction times, and excellent yields are other advantages of this reagent.
- Mohammadi, Mohammad Kazem,Ghammamy, Shahriare
-
experimental part
p. 139 - 144
(2012/04/23)
-
- A facile oxidation of thiols to disulfides catalyzed by CoSalen
-
A convenient and facile catalytic oxidation of thiols to the corresponding disulfides is described using CoSalen as the catalyst and air as the oxidizing agent. This new approach provides an efficient method for the preparation of symmetrical disulfides in high yields and under mild conditions. [Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: Spectroscopic Identification of Products 3a-3l.] Copyright Taylor and Francis Group, LLC.
- Tan, Cheng-Xia,Pan, Li-Yan,Zhang, Guo-Fu,Li, Yong-Shu
-
experimental part
p. 16 - 21
(2012/03/26)
-
- A mild and efficient protocol for oxidation of thiols to disulfides in water
-
A novel vanadium polyoxometalate [(C7H7)(CH 3)3N]3[H3V10O 28].3H2O works as a useful oxidant for the oxidation of thiols to disulfldes in water under mild reaction conditions in an excellent yield.
- Dewan, Anindita,Bora, Utpal,Kakati, Dilip K.
-
experimental part
p. 231 - 234
(2012/07/13)
-
- Easy and rapid method for disulfide syntheses using nanophase-manganese (VII) oxide coated clay
-
Disulfide bond formation by the oxidation of several thiol compounds using nanophase manganese (VII) oxide coated clay (NM7O coated clay) in chlorinated, nonchlorinated (toluene), and polar solvents (water) is described. During the process, nitro and methoxy groups remain unaffected. The NM7O coated clay is easily prepared, stable, and inexpensive to manufacture. Furthermore, this and other studies prove that NM7O coated clay properties, i.e., mineralogy, chemical, and reactivity, are different from KMnO4. This rapid and facile synthesis coupled with the use of the recyclable NM7O coated clay catalyst will save energy due to low temperature and rapid reaction times, as well as minimal disposal problems, thus decreasing production costs.
- Gondi, Sudershan R.,Son, David Y.,Biehl, Edward R.,Vempati, Rajan K.
-
scheme or table
p. 34 - 39
(2010/05/02)
-
- Tributylammonium halochromates/silica gel: Simple reagents for oxidative coupling of thiols to symmetrical disulfides
-
New orange solid tributylammonium halochromates, (C4H 9)3N+CrO3X-, TBAXC (X=F, Cl) are easily synthesized by the reaction of tributylammonium fluoride and chloride with CrO3 in a 1:1 molar ratio in the presence of HF and HCl. Tributylammonium halochromates(VI) are versatile reagent for the effective and selective oxidation of organic substrates. Silica gel supported TBAFC and TBACC are versatile reagents for the effective and selective oxidation of organic substrates, in particular, thiols, under mild conditions. Considerable improvements are observed in the presence of the absorbent, making the work-up much more convenient. New orange solid tributylammonium halochromates, (C 4H9)3N+CrO3X -, TBAXC (X=F, Cl) are easily synthesized by the reaction of tributylammonium fluoride and chloride with CrO3 in a 1:1 molar ratio in the presence of HF and HCl. Tributylammonium halochromates(VI) are versatile reagent for the effective and selective oxidation of organic substrates. Copyright
- Mohammadi, Mohammad Kazem,Ghammamy, Shahriare,Zarrinabadi, Soroush,Farjam, Mohammad Hossein,Sabayan, Behrang
-
experimental part
p. 2199 - 2203
(2011/10/09)
-
- A one-pot, efficient, and odorless synthesis of symmetrical disulfides using organic halides and thiourea in the presence of manganese dioxide and wet polyethylene glycol (PEG-200)
-
Primary, secondary, tertiary, allylic, and benzylic halides are converted efficiently into symmetric disulfides in high yields using thiourea as the sulfur atom source. The reactions are odorless and are performed at 30-35 °C in wet PEG-200 using MnO2 as an oxidant.
- Firouzabadi, Habib,Iranpoor, Nasser,Abbasi, Mohammad
-
experimental part
p. 508 - 509
(2010/10/02)
-
- Oxidative coupling of thiols to disulfides in solution with tripropylammonium halochromates, (C3H7) 3NH[CrO3X], (X=F, Cl) adsorbed on alumina
-
A mild and efficient method for the oxidative coupling of thiols by tripropylammonium fluorochromate and tripropylammonium chlorochromate absorbed on alumina in solution is reported. Alumina absorbed tripropylammonium fluorochromate and tripropylammonium chlorochromate are efficient and new reagents, which are easily prepared and oxidize thiols to the corresponding disulfides quickly. The reactions are clean and readily controlled to stop at the disulfide stage without the formation of common over-oxidized side products. Thus the advantages of the easy procedure and work up, short reaction times, and excellent yields make this a viable alternative method.
- Hassanijoshaghani, Ali,Ghammamy, Shahriare,Bagi, Shahryar,Moghimi, Ali,Javanshir, Zahra
-
experimental part
p. 164 - 170
(2009/04/10)
-
- Efficient oxidative coupling of thiols into disulfides using N-tert-butyl-N-chlorocyanamide
-
Reaction of aliphatic/aromatic/heterocyclic thiols with N-tert-butyl-N-chlorocyanamide in presence of sodium bromide is described. The reaction was very rapid and resulted in the formation of disulfides in excellent yields under mild conditions.
- Kumar, Vinod,Kaushik, Mahabir Parshad
-
experimental part
p. 160 - 162
(2009/04/06)
-
- Carboxy pyridinium bromide perbromide reagents, part I: Selective oxidation of thiols and sulfides
-
Efficient and convenient oxidation of aliphatic and aromatic thiols to disulfides and of sulfides to sulfoxides with pyridinium hydrobromide perbromide (PHBP), nicotinic acid hydrobromide perbromide (NAHBP), and 2,6-dicarboxy pyridinium hydrobromide perbromide (DCPHBP) in a solvent or under solvent free conditions and at ambient temperature is introduced. Copyright Taylor & Francis Group, LLC.
- Lakouraj, Moslem M.,Ghodrati, Keivan
-
experimental part
p. 1432 - 1439
(2009/05/07)
-
- Iron (III) perchlorate adsorbed on silica gel: A reagent for organic functional group transformations
-
Adsorption of Fe(ClO4)3(H2O)6 onto chromatographic-grade silica gel in the presence of organic solvents (S=water, acetonitrile, or lower fatty acids) produces a supported reagent, Fe(ClO4)3(S)6/SiO2. This reagent has been found to be effective for the rapid organic functional group transformations such as dimerization of alkynes, aromatic hydrocarbons, selective oxidation of thiols to disulfides, and transannular reactions in 1,5-cyclooctadienes on grinding using pestle and mortar in the solid state. Copyright Taylor & Francis Group, LLC.
- Parmar, Anupama,Kumar, Harish
-
p. 2301 - 2308
(2008/02/10)
-
- Simple method for the preparation of symmetrical alkyl and aryl disulfides with alkyl sulfonyl halides in nitrogenous base
-
In the present study, the reaction of thiols with alkyl sulfonyl halides was carried out in a nitrogenous base to compare the reactivity of -SH with that of -OH, which, however, led to the formation of disulfides. The reaction achieved as a result offers the use of an inexpensive reagent, quantitative yields of the product, and simplicity for the formation of the S-S bond. Copyright Taylor & Francis Group, LLC.
- Ali, Firdous Imran,Hashmi, Imran Ali,Siddiqui, Bina S.,Rasheed, Munawwer
-
p. 2461 - 2465
(2008/02/10)
-
- Unexpected reactivity of the Burgess reagent with thiols: Synthesis of symmetrical disulfides
-
(Equation Presented) Reaction of the Burgess reagent with a series of aliphatic and aromatic thiols led to the corresponding symmetrical disulfides in high yields. No olefins were detected in the reactions of aliphatic thiols.
- Banfield, Scott C.,Omori, Alvaro Takeo,Leisch, Hannes,Hudlicky, Tomas
-
p. 4989 - 4992
(2008/02/05)
-
- Oxidation of thiols to bisulfides using silica chloride as a heterogeneous catalyst
-
Silica chloride is used as a selective and effective heterogeneous catalyst for the rapid conversion of thiols to disulfides with quantitative yields in a very short period of time. Copyright
- Sathe, Manisha,Ghorpade, Ramarao,Kaushik, Mahabir Parshad
-
p. 1048 - 1049
(2007/10/03)
-
- Oxidation of thiols to disulfides with monochloro poly(styrenehydantoin) beads
-
Various thiols were converted to symmetrical disulfides. This facile and reproducible method uses water as a solvent, and monochloro poly(styrenehydantoin) beads as an oxidizing agent.
- Akdag, Akin,Webb, Thomas,Worley
-
p. 3509 - 3510
(2007/10/03)
-
- Method for preparing aromatic diphenyl thioethers
-
The invention concerns a method for preparing aromatic diphenyl thioethers. More particularly the invention concerns the preparation of 4-chloro-4′-thiomethyldiphenylether. The inventive method for preparing an aromatic diphenyl thioether is characterised in that it consists in reacting in an aqueous medium a diazonium salt of an aromatic diphenyl compound with a disulphide sulphur compound, in the presence of an efficient amount of a coupling catalyst.
- -
-
-
- Oxidation of thiols to disulfides with molecular bromine on hydrated silica gel support
-
Results of oxidation of thiols to disulfides with molecular bromine on silica gel solid support are reported. The procedure utilizes organic media and does not require a base to neutralize HBr by-products to suppress acid promoted side reactions. Utilization of silica gel support simplifies work up and product isolation.
- Ali, Mohammed Hashmat,McDermott, Mario
-
p. 6271 - 6273
(2007/10/03)
-
- Dinitrogen tetroxide supported on polyvinylpyrrolidone (PVP-N2O4): A new nitrosating and coupling agent for thiols and a selective oxidant for sulfides and disulfides
-
Gaseous N2O4 was immobilized on polyvinylpyrrolidone to give a stable polymeric reagent. Thiols were converted to S-nitrosothiols (thionitrites) using this new nitrosating agent in n-hexane or CHCl3 at 10°C. With this reagent, thiols were also converted into their corresponding disulfides. Selective oxidation of sulfides to sulfoxides and disulfides to thiosulfonates can also be achieved by this reagent at room temperature. By using an excess of the reagent, the selective one-pot synthesis of thiosulfonates from thiols at room temperature was also performed.
- Iranpoor, Nasser,Firouzabadi, Habib,Pourali, Ali-Reza
-
p. 5179 - 5184
(2007/10/03)
-
- Selective and simple phase transfer catalyzed synthesis of disulfides from thiols
-
Two novel methods of synthesis of disulfides from thiols or their Na salts in the phase transfer catalytic system CBr4/18-crown-6/benzene or toluene are developed and the products isolated in 67-8.8% yields.
- Abele, Edgars,Abele, Ramona,Lukevics, Edmunds
-
p. 624 - 625
(2007/10/03)
-
- One pot conversion of alcohols to disulfides mediated by benzyltriethylammonium tetrathiomolybdate
-
A one pot conversion of alcohols to disulfides in good yields via the activation of a hydroxyl group with DCC or P(NMe2)3 / CCl4 followed by treatment with benzyltriethylammonium tetrathiomolybdate is reported.
- Sinha, Surajit,Ilankumaran,Chandrasekaran
-
p. 14769 - 14776
(2007/10/03)
-
- Oxidation of thiols to bisulfides by elemental sulfur without contamination by higher polysulfides
-
Dialkyl disulfides were prepared in near quantitative yield by oxidation of alkanethiols with elemental sulfur using NaOH and ethoxylated alcohols as catalysts. Tergitol 15-S-7 was one of several ethoxylated alcohols which was used. Contamination by trisulfides was essentially eliminated in the disulfide products. The ratios of disulfide to trisulfide ranged from 100/0 to 99.6/0.4 for reactions with primary and secondary alkanethiols (100% excess) such as 1-propanethiol, 1-octanethiol, 2-propanethiol, and 2-butanethiol. The process did not work for tertiary alkanethiols such as 2-methyl-2-propanethiol where the trisulfide was greatly favored.
- Shaw, James E.,McAfee, Marilyn G.
-
p. 125 - 131
(2007/10/03)
-
- Selective and efficient transformation of thioethers to their sulfoxides and catalytic conversions of thiols to the disulfides with hydrated iron(III) and copper(II) nitrates in aprotic organic solvents or under solvent free conditions
-
Fe(NO3)3.9H2O and Cu(NO3)2.3H2O are efficient reagents for the conversion of thioethers to their sulfoxides in refluxing EtOAc in high yields. Fe(NO3)3.9H2O is also able to proceed the transformations under solvent free conditions at room temperature with excellent yields. Cu(NO3)2.3H2O is highly selective for the oxidation of aryl thioethers to the corresponding sulfoxides. Cu(NO3)2.3H2O also oxidizes catalytically thiols to their corresponding disulfides in excellent yields.
- Firouzabadi,Iranpoor,Zolfigol
-
p. 1179 - 1187
(2007/10/03)
-
- Iron (III) perchlorate: A novel reagent for functional group as well as ring transformations in organic synthesis
-
Oxidative dimerization of some aromatic hydrocarbons, diphenylacetylene and diphenyl amine, selective oxidation of thiols to disulfides, and transformation of 1,5-cyclooctadiene to the corresponding bicyclooctane derivatives through trans-annular reactions have been achieved using iron (III) perchlorate(ITP).
- Kumar, Baldev,Parmar, Anupama,Rajpal, Anita,Kumar, Harish
-
p. 593 - 595
(2007/10/03)
-
- A novel oxidizing reagent based on potassium ferrate(VI)
-
A new, efficient preparation has been devised for potassium ferrate(VI) (K2FeO4). The ability of this high-valent iron salt for oxidizing organic substrates in nonaqueous media was studied. Using benzyl alcohol as a model, the catalytic activity of a wide range of microporous adsorbents was ascertained. Among numerous solid supports of the aluminosilicate type, the K10 montmorillonite clay was found to be best at achieving quantitative formation of benzaldehyde, without any overoxidation to benzoic acid. The roles of the various parameters (reaction time and temperature, nature of the solvent, method of preparation of the solid reagent) were investigated. The evidence points to a polar reaction mechanism. The ensuing procedure was applied successfully, at room temperature, to oxidation of a series of alcohols to aldehydes and ketones, to oxidative coupling of thiols to disulfides, and to oxidation of nitrogen derivatives. At 75°C, the reagent has the capability of oxidizing both activated and nonactivated hydrocarbons. Toluene is turned into benzyl alcohol (and benzaldehyde). Cycloalkanes are also oxidized, in significant (30-40%) yields, to the respective cycloalkanols (and cycloalkanones). Thus, potassium ferrate, used in conjunction with an appropriate heterogeneous catalyst, is a strong and environmentally friendly oxidant.
- Delaude, Lionel,Laszlo, Pierre
-
p. 6360 - 6370
(2007/10/03)
-
- Use of a sacriflcial-sulfur electrode in electroorganic chemistry. V. Formation of the sequence CSSSC from S and thiols or thiolates
-
At a working potential of about +2.0 V (vs SCE) the carbon-sulfur electrode is a source of the electrogenerated cation S2+. In organic media, this electrophile reacts with thiols (or thiolates) to give a mixture of polysulfides of which the trisulfide is the main product. The reaction between electrogenerated Sy2- and alkyl halides is less selective. Elsevier,.
- Do, Quang Tho,Elothmani, Driss,Simonet, Jacques,Guillanton, Georges Le
-
p. 273 - 281
(2007/10/03)
-
- Disulfides. 1. Syntheses Using 2,2'-Dithiobis(benzothiazole)
-
2,2'-Dithiobis(benzothiazole) produces unsymmetric disulfides containing the 2-benzothiazolyl fragment in both high yield and purity when reacted with 1 equiv of a variety of alkane and arene thiols under mild conditions.In turn, these unsymmetric disulfides react with a variety of thiols to produce either symmetric disulfides or new unsymmetric disulfides in excellent yields.At room temperature, 2 equiv of most thiols are oxidized essentially quantitatively to the corresponding symmetric disulfide by 2,2'-dithiobis(benzothiazole).Thiols employed at various stages include 1-propanethiol, 2-propanethiol, 2-methyl-2-propanethiol, phenylmethanethiol, 2-mercaptoethanol, 2-mercaptoethylamine (MEA) hydrochloride, 2-methoxybenzenethiol, 4-methoxybenzenethiol, 4-aminobenzenethiol, 4-acetamidobenzenethiol, 4-bromobenzenethiol, 4-methylbenzenethiol, N-acetyl-L-cysteine, and sodium 2-mercaptoethanesulfonate (MESNA).Various disulfides were inactive in vivo against cyanide poisoning.
- Brzezinska, Ewa,Ternay, Andrew L.
-
p. 8239 - 8244
(2007/10/02)
-
- A New Reaction of the Azoxy Group with Alkyl Thiolates: Reduction to Amino via a Sulfenamido Intermediate
-
A novel alkyl thiolate-induced reduction of azoxybenzenes is reported to yield anilines via in situ decomposition of the corresponding sulfenamides formed as primary reaction products.
- Dario, Maria Teresa,Montanari, Stefano,Paradisi, Cristina,Scorrano, Gianfranco
-
p. 301 - 302
(2007/10/02)
-
- 2,4-N,N'-BIS(DIALKYLAMIDO)-2,4-DITHIOXO-1,3,2λ5,4λ5-DITHIADIPHOSPHETANES
-
2,4-N,N'-Bis(dialkylamido)-2,4-dithioxo-1,3,2λ5,4λ5-dithiadiphosphetanes were obtained by the interactions of tetraphosphorus decasulfide with sulfenamides.The reactions of amido-1,3,2,4-dithiadiphosphetane-2,4-disulfides obtained with diethyl disulfide, ethylsulfendiethylamide and trimethyl(diethylamino)silane were studied.Key words: Tetraphosphorus decasulfide, sulfenamides, 2,4-N,N'-bis(dialkylamido)-2,4-dithioxo-1,3,2λ5,4λ5-dithiadiphosphetanes.
- Nizamov, Il'Yas S.,Al'Metkina, Lyubov' A.,Kuznetzov, Vladislav A.,Batyeva, Elvira S.
-
p. 139 - 148
(2007/10/02)
-
- Thiol Anions in Nucleiphilic Aromatic Substitution Reactions with Activated Aryl Halides. Attack on Carbon vs Attack on Halogen
-
The reaction of o-iodonitrobenzene with thiol anions (RSNa, R = Me, 2-Pr, t-Bu) in 2-propanol solution produces the o-nitrophenyl thioether and nitrobenzene in relative proportions and with rates which depend on R.The results of kinetic analysis and of D-incorporation experiments are inconsistent with a radical chain mechanism as proposed earlier for the alkoxide-promoted hydro-de-halogenation of aryl halides.The data clearly indicate the involvement of a carbanionic intermediate (the o-nitrophenyl anion) and are consistent with a stepwise mechanism in which the first step is nucleophilic attack on iodine to form a sulphenyl halide and the o-nitrophenyl anion (a halogenophilic reaction).In contrast, the reaction of the other o-halonitrobenzenes (F, Cl, Br) produces exclusively the product of alkylthio-de-halogenation according to the addition/elimination (SNAr) mechanism.The fact that in these systems the reactivity of thiol anions results from their ability as bielectronic nucleophiles rather than as reducing agents is discussed.
- Montanari, Stefano,Paradisi, Cristina,Scorrano, Gianfranco
-
p. 5628 - 5631
(2007/10/02)
-
- Sodium Tellurite as a Mild and Selective Oxidizing Agent for Thiols: Its Use in the One-Pot Synthesis of Unsymmetrical Disulfides
-
Sodium tellurite acts as a mild and highly selective oxidizing agent for thiols under phase-transfer conditions at room temperature.Aromatic and benzylic thiols are rapidly converted to disulfides.Short-chain primary thiols undergo oxidation in preference to long-chain thiols.Secondary thiols are sluggish in oxidation and tertiary thiols remain intact.No overoxidation of the sulfur atom is observed.Similar results are also obtained with sodium tellurate.
- Suzuki, Hitomi,Kawato, Sei-ichi,Nasu, Akira
-
p. 626 - 627
(2007/10/02)
-
- EPR Detection of Aliphatic Disulfide Anion Radicals in Fluid Solution
-
Photolysis of alkylthiols (RSH) in EtOH/EtOK in the presence of ButOOBut yields the disulfide radical anions RSSR.- in conditions suitable for EPR detection in solution over a wide temperature range.
- Cremonini, Mauro A.,Lunazzi, Lodovico,Placucci, Giuseppe
-
p. 451 - 452
(2007/10/02)
-
- Process for the preparation of organic disulphides and polysulphides
-
The invention relates to the preparation of organic disulphides and polysulphides by the action of sulphur on a mercaptan or on a polysulphide which is lower in sulphur, in the presence of a basic catalyst. In the process according to the invention, an anion exchange resin is used as catalyst.
- -
-
-
- Preparation of ZnS and CdS by thermal degradation of (methanethiolato)zinc and -cadmium complexes, [M(SMe)2]n (M = Zn, Cd)
-
Reactions of aqueous MeSNa with ZnCl2 and with CdCl2 give the methanethiolato complexes [Zn(SMe)2]n (1a) and [Cd(SMe)2]n (2), respectively. Reaction of MeSH with ZnEt2 in hexane also gives [Zn(SMe)2]n (1b). [Zn(SEt)2]n (3) and [Zn(S-i-Pr)2]n (4) are obtained by reaction of EtSLi and i-PrSLi with ZnI2, respectively. Elemental analyses of the complexes give satisfactory results. Peaks in the X-ray diffraction pattern of 1b are considerably broader than those of 1a. Thermolysis of 1a and 1b at 260°C gives β-ZnS accompanied by evolution of MeSMe in almost quantitative yields. Thermolysis of 2 under similar conditions give CdS as a mixture of α- and β-forms. Thermogravimetric analyses of the thiolato compounds also suggest elimination of MeSMe in the vicinity of 230-240°C. TG curves of 1b and 2 at constant temperatures indicate that the thermolysis obeys first-order kinetics in [M(SMe)2]n. Activation parameters of the reactions are 143 and 191 kJ mol-1, respectively. Thermolysis of 1a obeys autocatalytic type kinetics expressed by the kinetic equation ln [x/(1 - x)] = kt + C (x: reacted fraction). Heating the (ethanethiolato)zinc complex 3 gives ZnS similarly to the case of 1a, 1b, and 2, while thermolysis of 4 is much slower than the reactions of these complexes.
- Osakada, Kohtaro,Yamamoto, Takakazu
-
p. 2328 - 2332
(2008/10/08)
-