- ACTIVATION OF NITROSO GROUP WITH THIOLS. A NEW TRANSFORMATION OF PRIMARY AMINES TO ORGANIC SULFIDES OR THIOLS
-
Aliphatic primary amines reacted with 2-mercaptobenzothiazole in the presence of t-butylnitrite at room temperature to give condensation products, 2-(alkylthio)benzothiazole.
- Ueno, Yoshio,Tanaka, Chie,Okawara, Makoto
-
-
Read Online
- Intrinsic and Extrinsic Control of the p Ka of Thiol Guests inside Yoctoliter Containers
-
Despite decades of research, there are still many open questions surrounding the mechanisms by which enzymes catalyze reactions. Understanding all the noncovalent forces involved has the potential to allow de novo catalysis design, and as a step toward this, understanding how to control the charge state of ionizable groups represents a powerful yet straightforward approach to probing complex systems. Here we utilize supramolecular capsules assembled via the hydrophobic effect to encapsulate guests and control their acidity. We find that the greatest influence on the acidity of bound guests is the location of the acidic group within the yoctoliter space. However, the nature of the electrostatic field generated by the (remote) charged solubilizing groups also plays a significant role in acidity, as does counterion complexation to the outer surfaces of the capsules. Taken together, these results suggest new ways by which to affect reactions in confined spaces.
- Cai, Xiaoyang,Kataria, Rhea,Gibb, Bruce C.
-
-
Read Online
- Amphiphilic dendrimer, synthesis method thereof, and application of amphiphilic dendrimer as drug delivery system
-
The invention relates to a microenvironment response type amphiphilic dendrimer, a synthesis method thereof, and application of the microenvironment response type amphiphilic dendrimer as a drug delivery system. The microenvironment response type amphiphilic dendrimer is a compound with a structure as shown in a formula (I), a formula (II) or a formula (III) or pharmaceutically acceptable salt of the compound. The compound disclosed by the invention can be used as the nano delivery system based on tumor microenvironment specific response, has good solubility in an aqueous solution, can be self-assembled with a drug in the aqueous solution to form a relatively stable nano compound, can effectively deliver the loaded drug to a tumor site; and can responsively disassembl the nano-drug delivery carrier under corresponding stimulation to achieve the purpose of accurate drug release, so that the drug can be released to the focus part to the greatest extent, and the compound is a novel nano-delivery carrier.
- -
-
Paragraph 0096-0097; 0108-0110
(2021/08/07)
-
- Effect of the presence of ionic liquid during the NiMoS bulk preparation in the transformation of decanoic acid
-
The impact of the presence and amount of [BMIM][NTf2] ionic liquid during the preparation of bulk NiMoS catalysts was investigated. It was clearly shown that these factors have a strong influence on both the morphology and specific surface area of the obtained NiMoS samples. Most interestingly the catalytic activity for the transformation of decanoic acid increased up to three times when IL was present during synthesis. In the same time, a greater selectivity towards hydrocarbons was observed. On the whole a clear relationship between catalytic activity, selectivity and NiMoS morphology was demonstrated. Consequently, it is possible to modify the morphology of the materials and impact the catalytic properties by changing the synthesis conditions.
- Leyral, Géraldine,Brillouet, Soizic,Rousseau, Julie,Richard, Frédéric,Mamede, Anne Sophie,Courthéoux, Laurence,Pradel, Annie,Ribes, Michel,Brunet, Sylvette
-
p. 120 - 132
(2017/01/11)
-
- Two-step three-component process for one-pot synthesis of 8-alkylmercaptocaffeine derivatives
-
A highly efficient, odourless and two-step three-component process for one-pot synthesis of some 8-alkylmercaptocaffeine derivatives has been described. The catalyst-free three-component reaction of alkyl bromides, thiourea, and 8-bromocaffeine gave 8-alkylmercaptocaffeine products in excellent to quantitative yields. In addition, the impact of parameters on sample reaction is discussed.
- Rad, M. N. Soltani,Maghsoudi
-
p. 70335 - 70342
(2016/08/06)
-
- 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)
-
- Simple, chemoselective hydrogenation with thermodynamic stereocontrol
-
Few methods permit the hydrogenation of alkenes to a thermodynamically favored configuration when steric effects dictate the alternative trajectory of hydrogen delivery. Dissolving metal reduction achieves this control, but with extremely low functional group tolerance. Here we demonstrate a catalytic hydrogenation of alkenes that affords the thermodynamic alkane products with remarkably broad functional group compatibility and rapid reaction rates at standard temperature and pressure.
- Iwasaki, Kotaro,Wan, Kanny K.,Oppedisano, Alberto,Crossley, Steven W. M.,Shenvi, Ryan A.
-
supporting information
p. 1300 - 1303
(2014/02/14)
-
- Molecularly ordered decanethiolate self-assembled monolayers on Au(111) from in situ cleaved decanethioacetate: An NMR and STM study of the efficacy of reagents for thioacetate cleavage
-
The cleavage of decanethioacetate (C10SAc) has been studied by 1H nuclear magnetic resonance (NMR) spectroscopy and scanning tunneling microscopy (STM) imaging of in situ prepared decanethiolate self-assembled monolayers (SAMs) on Au(111). Solutions of C10SAc (46 mM) and previously reported cleavage reagents (typically 58 mM) in CD3OD were monitored at 20 °C by NMR spectroscopy. Cleavage by ammonium hydroxide, propylamine, or hydrochloric acid was not complete within 48 h; cleavage by potassium carbonate was complete within 24 h and that by potassium hydroxide or 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) within 2 h. Similar cleavage rates were observed for phenylthioacetate. The degree of molecular ordering determined by STM imaging increased with increasing extent of in situ cleavage by these same reagents (2.5 mM C10SAc and 2.5 mM reagent in ethanol for 1 h, then 16 h immersion of Au/mica). Less effective cleavage reagents did not cleave the C10SAc sufficiently to decanethiol (C10SH) and gave mostly disordered SAMs. In contrast, KOH or DBU completely cleaved the C10SAc to C10SH and led to well-ordered SAMs composed of (3 × 3)R30° domains that are indistinguishable from SAMs grown from C10SH. Monolayer formation from thioacetates in the absence of cleavage agents is likely due to thiol or disulfide impurity in the thioacetates. Eliminating disulfide by using Bu 3P as a sacrificial reductant also helped to produce good molecular order in the SAM. The methods presented here allow routine growth of molecularly ordered alkanethiolate SAMs from thioacetates using reagents of ordinary purity under ambient, benchtop conditions.
- Singh, Anuradha,Dahanayaka, Daminda H.,Biswas, Abhijit,Bumm, Lloyd A.,Halterman, Ronald L.
-
experimental part
p. 13221 - 13226
(2010/12/25)
-
- 3-(2-aminophenyl)-4-methyl-1,3-thiazole-2(3H)-thione as an ecofriendly sulphur transfer agent to prepare alkanethiols in high yield and high purity
-
A new process is described for preparing very pure linear alkanethiols and linear α,ω-alkanedithiols using a sequential alkylation of the title compound, followed by a ring closure to quantitatively give the corresponding 3-methyl[1,3]thiazolo[3,2-a]-[3,1
- Mehdid, Mohammed Amine,Djafri, Ayada,Roussel, Christian,Andreoli, Federico
-
experimental part
p. 4634 - 4643
(2010/04/06)
-
- Thioacetate deprotection
-
A method of thioacetate deprotection by providing a compound of the formula R1—S—CO—R2, and reacting the compound with a quaternary ammonium cyanide salt in the presence of a protic solvent in an inert atmosphere to convert the compound to a product of the formula R1—SH. R1 is an organic group in which the bonding to sulfur is through a saturated carbon, and R2 is an aliphatic group.
- -
-
-
- Deacylation of esters, thioesters and amides by a naphthalene-catalysed lithiation
-
The reaction of different esters, thioesters and amides derived from pivalic, benzoic and 4-tert-butylbenzoic acids with an excess of lithium and a catalytic amount of naphthalene (8 mol%) led, after methanolysis, to the corresponding alcohols, thiols and amines, respectively, through a reductive non-hydrolytic procedure. This methodology represents a reasonable alternative to other non-reductive protocols. Georg Thieme Verlag Stuttgart.
- Behloul, Cherif,Guijarro, David,Yus, Miguel
-
p. 309 - 314
(2007/10/03)
-
- Deallyloxy- and debenzyloxycarbonylation of protected alcohols, amines and thiols via a naphthalene-catalysed lithiation reaction
-
The naphthalene-catalysed lithiation of Alloc- and Cbz-protected alcohols, amines and thiols in THF at 0°C led, after quenching with methanol, to the recovery of the free alcohols, amines and thiols in short reaction times and with very good yields. The selectivity for the removal of the Alloc- or the Cbz- group in a polyfunctionalised substrate has been studied. The selective reductive cleavage of a benzylic carbon-oxygen bond was achieved in the presence of an allylic carbon-oxygen or carbon-nitrogen bond. This method represents a great improvement in comparison with the previously reported deprotection procedures by dissolving metals, since it avoids the use of the toxic liquid ammonia and, therefore, the need to perform the reaction at low temperatures.
- Behloul, Cherif,Guijarro, David,Yus, Miguel
-
p. 9319 - 9324
(2007/10/03)
-
- Aliphatic thioacetate deprotection using catalytic tetrabutylammonium cyanide
-
A series of thiol-functionalized organic compounds were selected to analyze the scope and efficiency of a new thioacetate deprotection method using catalytic tetrabutylammonium cyanide (TBACN) to effect the transformation of a thioacetate group to a free thiol in the presence of a protic solvent. Particularly attractive are the mild reaction and workup conditions, reduced byproduct formation typically seen using literature methods and yields of greater than 80% for the free aliphatic thiols. This method is effective on aliphatic thiols with trityl, benzyl, p-halo-benzyl, phenethyl, phenoxyethyl, and cyclohexylethyl structural moieties, but it is not effective with thiophenols.
- Holmes, Brian T.,Snow, Arthur W.
-
p. 12339 - 12342
(2007/10/03)
-
- Desilylation procedure via a naphthalene-catalysed lithiation reaction
-
The reaction of silyl protected alcohols, amines and thiols with lithium powder and a catalytic amount of naphthalene, in THF, at 0°C led, after hydrolysis, to the recovery of the free alcohols, amines and thiols in very good yields. At least a phenyl group was required in the silyl protecting group for the success of the reaction. Some polyfunctionalised starting materials have successfully been deprotected. The stereochemical outcome of the deprotection of a silylated chiral secondary alcohol has also been studied and no racemization was observed. The process has shown to be a good alternative to the acid-catalysed desilylation procedures, the latter being not useful for the deprotection of some silylated tertiary alcohols.
- Behloul, Cherif,Guijarro, David,Yus, Miguel
-
p. 6908 - 6915
(2007/10/03)
-
- Water effects on SmI2 reductions: A novel method for the synthesis of alkyl thiols by SmI2-promoted reductions of sodium alkyl thiosulfates and alkyl thiocyanates
-
Water as a cosolvent has significant improving effect on the reductivity of SmI2 in the reduction of sodium alkyl thiosulfates and alkyl thiocyanates. A new method for synthesis of alkyl thiols by SmI 2/THF/H2O system has been developed.
- Zhan, Zhuang-Ping,Lang, Kai,Liu, Feng,Hu, Li-Ming
-
p. 3203 - 3208
(2007/10/03)
-
- Cleavage of a p-cyanobenzyl group from protected alcohols, amines, and thiols using triethylgermyl sodium
-
Alcohols, amines, and thiols protected with a p-cyanobenzyl group can be easily and quantitatively deprotected using triethylgermyl sodium under mild conditions.
- Yokohama, Yasuo,Takizawa, Shuichi,Nanjo, Masato,Mochida, Kunio
-
p. 1032 - 1033
(2007/10/03)
-
- A novel, practical and highly chemoselective methodology for reduction of disulphides to thiols
-
A novel, simple and efficient method for the reduction of disulfides to thiols using In/NH4Cl is described.
- Vidya Sagar Reddy,Venkat Rao,Iyengar
-
p. 859 - 862
(2007/10/03)
-
- A general and mild synthesis of thioesters and thiols from halides
-
The conversion of a wide variety of halides to thioesters by reaction with potassium thiocetate under mild conditions is described, and the generality of the method is demonstrated.
- Zheng, Tu-Cai,Burkart, Maureen,Richardson, David E.
-
p. 603 - 606
(2007/10/03)
-
- β-carboxy sulfonamide ACAT inhibitors
-
β-Carboxy sulfonyl compounds of the formula STR1 wherein R1 is aryl, R3 is hydrogen or alkyl, R3 and R4 are hydrogen or alkyl, Y is --O--, --S--, or --NR2 --, and R5 is alkyl or aryl are potent inhibitors of the enzyme acyl CoA:cholesterol acyltransferase (ACAT) and are thus useful for treating hypercholesterolemia and atherosclerosis.
- -
-
-
- Antimicrobial composition and method containing N-(3,5-dihalophenyl)-imide compounds
-
Novel N-(3,5-dihalophenyl)imide compounds, which exhibit a strong antimicrobial activity against microorganisms including phytopathogenic fungi, parasites of industrial products and pathogenic microorganisms, represented by the formula, STR1 wherein X and X' each represent halogens and A represents a substituted ethylene such as chloroethylene, C1 - C4 alkylthioethylene, C1 - C2 alkyl-ethylene or 1,2-di-C1 - C2 -alkyl-ethylene, a cyclopropylene such as 1,3-dimethylcyclopropylene, trimethylene, a cyclohexylene-1,2-, cyclohexenylene-1,2-, cyclohexadienylene-1,2- or o-phenylene. The N-(3,5-dihalophenyl)imide compounds can be obtained by any of methods which produce imide compounds or reaction of an N-(3,5-dihalophenyl)maleimide compound with a mercaptan, a hydrogen halide, phosphorus chloride or thionylchloride.
- -
-
-
