13532-18-8Relevant articles and documents
A mechanistic rationalisation for the substrate specificity of recombinant mammalian 4-hydroxyphenylpyruvate dioxygenase (4-HPPD)
Crouch, Nicholas P.,Adlington, Robert M.,Baldwin, Jack E.,Lee, Meng -Huee,MacKinnon, Colin H.
, p. 6993 - 7010 (1997)
The isolation and purification of α-ketoisocaproate dioxygenase [α-KICD] from rat liver is described. Sequence determination of the purified protein revealed it to have complete homology to rat liver 4-hydroxyphenylpyruvate dioxygenase [4-HPPD] which was confirmed by the cloning and expression of the gene encoding 4-HPPD in E. coli. Examination of the substrate specificity of the resulting soluble recombinant protein revealed it to be capable of the oxidative decarboxylation of a range of ketoacids derived from proteinogenic amino acids. The significance of the turnover of these different ketoacids is discussed in relation to the mechanism of this fascinating enzyme.
Identification and stereochemistry of the product of 4-HPPD catalyzed oxidation of the ketoacid of methionine
Adlington, Robert M.,Baldwin, Jack E.,Crouch, Nicholas P.,Lee, Meng-Huee,MacKinnon, Colin H.
, p. 2003 - 2006 (1996)
4-Hydroxyphenylpyruvate dioxygenase catalyzes the conversion of 2-oxo-5-thiahexanoic acid 1, the ketoacid from methionine to an unequal mixture of 4-thiapentanoic acid-4-oxide enantiomers 2a.
Neighboring Group Participation in Radicals: Pulse Radiolysis Studies on Radicals with Sulfur-Oxygen Interaction
Mahling, Sabine,Asmus, Klaus-Dieter,Glass, Richard S.,Hojjatie, Massoud,Wilson, George S.
, p. 3717 - 3724 (1987)
Neighboring group participation by alcohol and carboxylate groups resulting in kinetic and thermodynamic stabilization of an oxidized sulfur atom in various organic sulfides is reported.The resulting radical intermediates of the general type are characterized by an optical absorption in the 400-nm range and exhibit lifetimes of up to several hundred microseconds in aqueous solution under pulse radiolysis conditions.Significant sulfur-oxygen interaction seems to occur, however, only if both heteroatoms are separated by three or four carbon atoms in the unoxidiz ed molecule which enables favorable five- or six-membered ring structures in the radical intermediates.This geometric effect can additionally be favored by minimizing the free rotation of the functional groups through rigid molecular structures, e.g., in norbornane derivatives, and introduction of particular substituents.A most suitable function for stabilization of an oxidized sulfur atom seems to be a carboxylate group where an overall radical of the general structure is formed.In these species stabilization can be envisaged to involve the carboxylate group as a whole rather than only an individual oxygen atom.The bond strength of the sulfur-carboxylate interaction is estimated to be of the order of 50 kJ mol-1 as deduced from the temperature dependence of its dissociation.Further evidence for net sulfur-carboxylate bonding is provided by rate constants of 105-107 M-1s-1 for its proton-assisted decay.These rates are considerably lower than for the diffusion controlled protonation of free carboxylate functions.Oxidation of endo-2-(2-hydroxyisopropyl)-endo-6-(methylthio)bicycloheptane yields a transient where sulfur-oxygen interaction is associated with a strong acidification of the alcoholic hydroxyl group.A pK = 5.9 has been measured for the equilibrium.All the results on these transient radical intermediates can be viewed in terms of neighboring group participation.Such participation is also clearly evidenced in the formation and properties of intermolecular radical cations, , derived from these sulfides, and in the kinetics of the primary oxidation proces.Absolute rate constants for the one-electron oxidation of various sulfides by CCl3OO. radicals, for example, have been found to range from 3*108 to -6 M-1 s-1 depending on the nature of the oxygen containing functional groups.The present results are finally discussed in terms of the general possibility of stabilization of an oxidized sulfur function by other heteroatoms.Several electronic structures including the two-center-three (2?/1?*) electron bond can be advanced to describe the physicochemical properties of the radicals with sulfur-oxygen interaction.
Methoxymethyl Cations. 2. Reactions with Allylic Ethers and Sulfides in the Gas Phase
Kim, Jhong K.,Bonicamp, Judith,Caserio, Marjorie C.
, p. 4236 - 4242 (1981)
Reactions of allylic compounds 3-methoxy-1-propene and 3-(methylthio)-1-propene with gaseous methoxymethyl cations generated from methyl ethers on electron impact have been investigated by ion cyclotron resonance techniques.Three modes of reaction have been identified for the allylic sulfide with CH3OCH2+ that correspond to the elimination of the elements of CH2=O, CH3OH, and CH3SH.The allylic ether and CH3OCH2+ reacted to eliminate CH3OH predominantly.Pathways for these reactions were studied by using isotopic labels.The results are interpreted in terms of attack of the reactant ion at the terminal carbon of the allyl group followed by hydride and/or proton transfers and elimination of CH2O, CH3OH, or CH3SH.Oxygen lost as the neutral arose predominantly but not exclusively by cleavage of the methylene-oxygen bond of the reactant ion.Methylthiolation of 3-(methylthio)-1-propene also was achieved by reaction with CH3OCH2+ in the presence of methyl disulfide.The score of a small amount of label scrambling in deuterium-labeled reactant ions is discussed.
Pd-Catalyzed Intermolecular Transthiolation of Ar-OTf Using Methyl 3-(Methylthio) Propanoate as a Thiol Surrogate
Pan, Dandan,Xu, Shasha,Tian, Qingqiang,Li, Yahui
supporting information, p. 4616 - 4619 (2021/09/10)
A method for the odorless synthesis of unsymmetrical sulfides via Csp2?O and Csp3?S bond activation is presented. Using methyl 3-(methylthio) propanoate as a MeSH surrogate, a series of substituted aryl methyl sulfides have been obtained in moderate to good yields. This catalytic protocol can also tolerate methyl 3-(methylthio)propionate derivatives to afford the corresponding aryl sulfides.
Synthesis of Highly Enantioenriched Sulfonimidoyl Fluorides and Sulfonimidamides by Stereospecific Sulfur–Fluorine Exchange (SuFEx) Reaction
Greed, Stephanie,Briggs, Edward L.,Idiris, Fahima I. M.,White, Andrew J. P.,Lücking, Ulrich,Bull, James A.
supporting information, p. 12533 - 12538 (2020/09/16)
Sulfonimidamides present exciting opportunities as chiral isosteres of sulfonamides, with potential for additional directional interactions. Here, we present the first modular enantioselective synthesis of sulfonimidamides, including the first stereoselective synthesis of enantioenriched sulfonimidoyl fluorides, and studies on their reactivity. A new route to sulfonimidoyl fluorides is presented from solid bench-stable, N-Boc-sulfinamide (Boc=tert-butyloxycarbonyl) salt building blocks. Enantioenriched arylsulfonimidoyl fluorides are shown to be readily racemised by fluoride ions. Conditions are developed, which trap fluoride and enable the stereospecific reaction of sulfonimidoyl fluorides with primary and secondary amines (100 % es, es=enantiospecificity) generating sulfonimidamides with up to 99 % ee. Aryl and alkyl sulfonimidoyl fluoride reagents are suitable for mild late stage functionalisation reactions, exemplified by coupling with a selection of complex amines in marketed drugs.
Pummerer rearrangement using bis(p-nitrophenyl) phosphorazidate as an azidation reagent: A novel synthesis of azidomethyl sulfides
Ishihara, Kotaro,Shioiri, Takayuki,Matsugi, Masato
supporting information, p. 3932 - 3935 (2017/09/20)
A novel method for the synthesis of azidomethyl sulfides by Pummerer rearrangement using bis(p-nitrophenyl) phosphorazidate (p-NO2DPPA) as an azidation reagent was developed. Various methyl sulfoxides were converted into the corresponding azidomethyl sulfides. Importantly, this reaction enables the preparation of azidomethyl sulfides without the use of toxic or explosive azide sources.
Chemical differentiation of three DMSP lyases from the marine: Roseobacter group
Burkhardt, Immo,Lauterbach, Lukas,Brock, Nelson L.,Dickschat, Jeroen S.
supporting information, p. 4432 - 4439 (2017/07/10)
Dimethylsulfoniopropionate (DMSP) catabolism of marine bacteria plays an important role in marine and global ecology. The genome of Ruegeria pomeroyi DSS-3, a model organism from the Roseobacter group, harbours no less than three genes for different DMSP lyases (DddW, DddP and DddQ) that catalyse the degradation of DMSP to dimethyl sulfide (DMS) and acrylate. Despite their apparent similar function these enzymes show no significant overall sequence identity. In this work DddQ and DddW from R. pomeroyi and the DddP homolog from Phaeobacter inhibens DSM 17395 were functionally characterised and their substrate scope was tested using several synthetic DMSP analogues. Comparative kinetic assays revealed differences in the conversion of DMSP and its analogues in terms of selectivity and overall velocity, giving additional insights into the molecular mechanisms of DMSP lyases and into their putatively different biological functions.
A novel method for the reduction of sulfoxides with the N, N, N g, N g-tetrabromobenzene-1,3-disulfonamide (TBBDA)/PPh3 system
Ghorbani-Vaghei, Ramin,Shiri, Lotfi,Ghorbani-Choghamarani, Arash
, p. 1002 - 1006 (2014/12/10)
A new method is described for the reduction of sulfoxides to sulfides using N,N,N',N'-tetrabromobenzene-1,3-disulfonamide [TBBDA] in combination with triphenylphosphine. Good to excellent yields, short reaction times, high efficiency and facile isolation of the desired products are the advantages of this method.
An atom-economic and odorless thia-Michael addition in a deep eutectic solvent
Azizi, Najmedin,Yadollahy, Zahra,Rahimzadeh-Oskooee, Amin
, p. 1722 - 1725 (2014/03/21)
The first 100% atom-efficient and odorless protocol for carbon-sulfur bond formation in a deep eutectic solvent (DES) as both the reaction medium and catalyst is reported. The biodegradable and inexpensive DES provides an efficient and convenient ionic reaction medium for the thia-Michael addition with in situ generation of S-alkylisothiouronium salts in place of thiols without the urea by-product segment. This protocol offers several advantages including short reaction times, high yields, clean reactions, and inexpensive and commercially available starting materials.
