2168-78-7Relevant articles and documents
A novel approach for the synthesis of imidazo and triazolopyridines from dithioesters
Ramesha, Ajjahalli B.,Sandhya, Nagarakere C.,Pavan Kumar, Chottanahalli S.,Hiremath, Mahanthawamy,Mantelingu, Kempegowda,Rangappa, Kanchugarakoppal S.
, p. 7637 - 7642 (2016)
T3P-DMSO mediated desulfurative cyclization of in situ generated thioamides serves as an efficient and versatile method for the synthesis of imidazo[1,5-a]pyridines and [1,2,4]-triazolo[4,3-a]pyridines with good to excellent yields. Substrates such as 2-methylaminoquinoline and pyrazin-2-yl-methanamine also undergo the corresponding reactions at room temperature. This efficient protocol has several advantages such as mild conditions, short reaction time, operational simplicity and high yields.
Visible-Light Photocatalytic Oxidation of DMSO for RAFT Polymerization?
Thum, Matthew D.,Hong, Donald,Zeppuhar, Andrea N.,Falvey, Daniel E.
, p. 1335 - 1342 (2021)
The solvent is an important, yet often forgotten part of a reaction mechanism. Many photochemical polymerizations are carried out using dimethyl sulfoxide (DMSO) as a way to promote the solubility of both the reactants and products, but its reactivity is rarely considered when initiation mechanisms are proposed. Herein, the oxidation of DMSO by an excited-state quinone is used to form initiating radicals resulting in the polymerization of methacrylate monomers, and the polymerization can be controlled with the addition of a chain transfer agent. This process leads to the formation of polymers with narrow molecular weight distribution, and the polymerization is able to be carried out in the presence of oxygen. A visible light absorbing substituted anthraquinone is synthesized, and nanosecond transient absorption spectroscopy is used to monitor the intermediates involved in the initiation mechanism. Photoproduct analysis indicates formation of methyl radicals as a result of DMSO oxidation. Furthermore, we show that the solvent outcompetes the chain transfer agent for interacting with the excited-state anthraquinone. These observations have a broad impact on photoinduced polymerizations performed in DMSO as many photocatalysts are strong oxidants in the excited state and are capable of reacting with the solvent. Therefore, the role of the solvent needs to be more carefully considered when proposing mechanisms for photoinduced polymerizations in DMSO.
Thioamide-substituted cinchona alkaloids as efficient organocatalysts for asymmetric decarboxylative reactions of MAHOs
Singjunla, Yuttapong,Pigeaux, Morgane,Laporte, Romain,Baudoux, Jér?me,Rouden, Jacques
, p. 4319 - 4320 (2018/08/24)
A new class of thioamide-substituted cinchona derivatives is reported. A convergent and practical approach was developed to insert the thioamide functional group onto the cinchonidine from readily available dithioesters. These organocatalysts were effective in asymmetric decarboxylative Mannich and protonation reactions of α-amido-substituted malonic acid half oxyesters (MAHOs), affording α,β- and α-amino acid derivatives, respectively, in good yields and stereoselectivities.
Nickel-heterocumulene complexes stabilized by trimethylphosphine: Synthesis, characterization and catalytic application in organozinc coupling with CS2
Huang, Ning,Li, Xiaoyan,Xu, Wengang,Sun, Hongjian
, p. 446 - 451 (2013/02/25)
The reactivity of Ni(PMe3)4 with CO2, CS2 and SCNPh was studied. Although CO2 is structurally homologous compound with CS2 and SCNPh, its reactivity with Ni(PMe3)4 shows a different result with those of CS 2 and SCNPh. Reactions of Ni(PMe3)4 with carbon disulfide and phenyl isothiocyanate in THF give the tetrahedral coordinate complexes (Me3P)3Ni(η2-CS2) (1) and (Me3P)3Ni(η2-SCNPh) (3), characterized by standard spectroscopic methods and X-ray diffraction. Nickel(0) complexes 1 and 3 are stabilized by the strong donor ligand PMe3. In the case of CO2, attempts to isolate the expected nickel(0) complex (Me 3P)3Ni(η2-CO2) (4) proved to be unsuccessful. To further extend the utility of our nickel catalysts, the catalytic coupling of organozinc bearing different functionalities with CS 2 was explored. With 10 mol% of 1 as the catalyst, MeZnMe, EtZnEt and PhZnBr coupled with CS2 to form the corresponding methyl dithiocarboxylate following esterfication of the initial products.
Efficient new protocol to synthesize aromatic and heteroaromatic dithioesters
Abrunhosa, Isabelle,Gulea, Mihaela,Masson, Serge
, p. 928 - 934 (2007/10/03)
A very efficient, high yielding procedure to synthesize substituted aromatic and heteroaromatic dithioesters is described. It involves the reaction between (phenylsulfonyl)methyl (hetero)aromatic derivatives and elemental sulfur in basic medium, followed by alkylation.
Thiadiazolyl and oxadiazolyl phenyl oxazolidinone antibacterial agents
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, (2008/06/13)
The present invention provides thiadiazolyl and oxadiazolyl phenyl oxzolidinone compounds of formula I STR1 wherein Q is thiadiazolyl or oxadiazolyl; wherein X1 and X2 are independently hydrogen, fluorine or chlorine; and wherein R1 is, for example, --COCH3 or --COCH2 CH3. These compounds are useful antimicrobial agents, effective against a number of human and veterinary pathogens, including gram-positive and gram-negative aerobic bacteria.
Dithiocarboxylic Acids, Dithiocarboxylic Esters, or Thiocarboxylic Amides by Reaction of Methylene-active Chloromethyl Compounds with Sulfur
Thiel, W.,Mayer, R.
, p. 243 - 262 (2007/10/02)
With a mixture of sulfur and amine in DMF at room temperature halomethyl compounds (1,5-10) can be oxidized to give thiocarboxylic acids (2,11-16) and their derivatives (3,4,17-35).We studied this reaction in detail especially with chloroacetic derivatives (11-15) or chloromethyl heterocycles (16) formally derived from chloroacetic acid.The resulting thiooxalic acid derivatives (11-27) represent activated acids and very useful C2-synthons, especially for the synthesis of heterocycles.Oxidation in the presence of triethylamine leads to dithiocarboxylates (11-16) which can be alkylated to dithioesters (17-27) in high yields.As a rule, with different primary and secondary amines instead of tertiary amines these dithiocarboxylates or dithiocarboxylic esters can be transformed already at low temperatures to thioamides (28-35).
THE REACTION OF CARBOXYLIC ACID CHLORIDES WITH O,O-DIALKYLDITHIOPHOSPHORIC ACIDS
Yousif, N. M.
, p. 79 - 82 (2007/10/02)
At high temperature (130 deg C), carboxylic acid chlorides react with O,O-dialkyldithiophosphoric acids (RO)2P(=S)(SH), Ia-c to give the corresponding dithiester RC(=S)(SR) II in varying yields, while benzoyl chloride reacts with compounds Ia, b at 20 deg C to give the corresponding S-benzoyl-O,O-dialkyldithiophosphate (RO)2P(=S) IIIa, b.Mechanistic consideration on the formation of the products are discussed.Key words: Carboxylic acid chlorides; O,O-dialkyldithiophosphoric acids, and S-benzoyl-O,O-dialkyldithiophosphates.
Reduction of Thionoesters to Ethers by Triorganotin Hydrides
Smith, Colin,Tunstad, Linda M.,Gutierrez, Carlos G.
, p. 257 - 260 (2007/10/02)
Esters 1 are efficiently deoxygenated to the corresponding ethers 3 in two steps by first conversion to the thionoesters 2 and subsequent reduction of these by triorganotin hydrides.
