55843-16-8Relevant articles and documents
Ni/Ir-Catalyzed Photoredox Decarboxylative Coupling of S-Substituted Thiolactic Acids with Heteroaryl Bromides: Short Synthesis of Sulfoxaflor and Its SF5 Analog
Kanishchev, Oleksandr S.,Dolbier, William R.
supporting information, p. 7677 - 7681 (2017/06/06)
Metallaphotoredox cross-coupling reactions have recently emerged as a powerful tool for the construction of C(sp2)?C(sp3) bonds between alkyl chains and aromatic systems, including electron-deficient heteroaryls, which are known to be challenging coupling partners. In this article, we disclose the Ni/Ir-catalyzed photoredox decarboxylative coupling of readily available S-substituted thiolactic acids with electron-deficient heteroaryl bromides, which resulted in the formation of simple but otherwise not easily accessible heteroarenes with alkylsulfide side chains. To demonstrate a practical use of this coupling reaction, we have shown its efficiency in the one-step synthesis of a key intermediate in the synthesis of the recently marketed insecticide Sulfoxaflor, and for the short synthesis of SF5-Sulfoxaflor.
Correlation of rates of uncatalyzed and hydroxide-ion catalyzed ketene hydration. A mechanistic application and solvent isotope effects on the uncatalyzed reaction
Andraos, John,Kresge, A. Jerry
, p. 508 - 515 (2007/10/03)
Rates of hydration of a number of ketenes were measured in neutral and basic solution using flash photolytic techniques, and rate constants for their uncatalyzed, k(uc), and hydroxide-ion catalyzed, k(HO), reactions were determined. These results, plus additional data from the literature, were found to provide the remarkably good correlation log k(uc) = -3.21 + 1.14 log k(HO), which spans 10 orders of magnitude in reactivity and includes 31 ketenes. This good correlation implies that uncatalyzed and hydroxide-ion catalyzed ketene hydraton occur by similar reaction mechanisms, which for the hydroxide-ion catalyzed process is known to involve nucleophilic attack on the carbonyl carbon atom of the ketene. Rate constants for phenylhydroxyketene, on the other hand, do not fit this correlation, which suggests that the mechanistic assignment upon which these rate constants are based may not be correct. Solvent isotope effects on these uncatalyzed ketene hydrations are weak; most are less than k(H)/k(D) = 2. It is argued that these isotope effects are largely, if not entirely, secondary in nature and that they are consistent with both a reaction mechanism in which nucleophilic attack of a single water molecule on the ketene carbonyl carbon atom produces a zwitterionic intermediate and also a mechanism that avoids this intermediate by passing through a cyclic transition state involving several water molecules.
Solvent isotope effect on the hydroxide-ioncatalyzed hydration of ketenes in aqueous solution
Andraos,Chiang,Eustace,Kresge,Paine,Popik,Sung
, p. 459 - 462 (2007/10/03)
Five ketenes, phenyl(ethyl)ketene, phenyl(methylthio)ketene, diphenylketene, pentafluorophenylketene, and 1-naphthylketene, were generated flash photolytically and solvent isotope effects (H2O vs. D2O) on their hydroxide-ioncatalyzed hydration in aqueous solution were determined. The values obtained are all weakly reverse and closely similar (k(HO)/k(DO) = 0.76-0.97), as expected for these fast, hydroxide-ion-consuming reactions, known to proceed by nucleophilic attack of hydroxide on the ketene carbonyl group. The characteristic magnitude of these isotope effects should prove useful in identifying new examples of this reaction.
Methylthio Group Migration in the Acid-Catalyzed Hydrolysis of S-Methyl Phenyldiazothioacetate. Kinetics and Mechanism of the Reaction
Jones, J.,Kresge, A. J.
, p. 2658 - 2662 (2007/10/02)
The acid-catalyzed hydrolysis of S-methyl phenyldiazothioacetate, C6H5C(=N2)COSCH3, in aqueous solution at 25 deg C was found to occur with the hydronium ion isotope effect kH(1+)/KD(1+)=3.08 and to give a Bronsted relation, based on carboxylic acid catalysts, whose exponent is α=0.70.This is taken to mean that the reaction occurs by rate-determining proton transfer to the diazo carbon atom.The principal product of the reaction, however, is α-(methylthio)-α-phenylacetic acid, C6H5CH(SCH3)CO2H, which must be formed by 1,2-shift of the methylthio group.An argument is presented which suggests that this shift is accompanied by a rate acceleration and that it consequently must take place in the rate-determining step of the reaction.
Flash Photolytic Generation and Reactivity of Phenyl(methylthio)ketene in Aqueous Solution
Jones, J.,Kresge, A. J.
, p. 6467 - 6469 (2007/10/02)
Methyl phenyldiazothioacetate is found to undergo Wolff rearrangement to phenyl(methylthio)ketene upon flash photolysis in aqueous solution and not to add water forming an ester enol as is the case with its oxygen analog, methyl phenyldiazoacetate.Hydrati
Metalation reactions. VIII. Metalation of benzyl methyl sulfide
Cabiddu, Salvatore,Floris, Constantino,Melis, Stefana,Sotgiu, Francesca
, p. 61 - 64 (2007/10/02)
The metalation of benzylmethyl sulfide with n-butyllithium in hexane and in the presence of TMEDA has been investigated.The results show that metalation occurs only at the benzylic position with no wittig type rearrangement, cleavage of thioether bond and
A Convenient Method for Preparation of 2-(Methylthio)alkanoic Acids and Their Related Compounds Using the Carbanions of Substituted Malonic Esters
Ogura, Katasuyuki,Itoh, Hiroshi,Morita, Toshio,Sanada, Kunio,Iida, Hirotada
, p. 1216 - 1220 (2007/10/02)
Starting from alkyl- or aryl-substituted malonic esters prepared by various methods, 2-(methylthio)alkanoic acids are synthesized by successive treatment with sodium ethoxide and with S-methyl methanethiosulfonate, followed by alkaline hydrolysis which causes concurrent decarboxylation.Production of 2-(phenylthio)alkanoic acids is also achieved in a similar manner.
METALATION REACTIONS. VII. METALATION OF BENZYLALKYL AND β-PHENETHYLALKYL SULFIDES
Cabiddu, S.,Floris, C.,Melis, S.,Piras, P. P.,Sotgiu, F.
, p. 149 - 156 (2007/10/02)
The products from the reaction between n-butyllithium and benzylalkyl and β-phenethylalkyl sulfides followed by carbonation, have been investigated by GLC/MS analysis.With benzylalkyl sulfides metalation occurs at the benzylic position, and the corresponding carboxylic acid can be isolated, but side products from Wittig like rearrangement, cleavage of the thioether bond, and aliphatic and aromatic substitution are also obtained.No benzylic metalation or Wittig-like rearrangement products are obtained from β-phenethyl sulfides: instead cleavage of the thioether bond and aliphatic and aromatic substitution occur.
