17431-94-6Relevant academic research and scientific papers
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.
, p. 7677 - 7681 (2017)
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.
Enantioselective Synthesis of α-Thiocarboxylic Acids by Nitrilase Biocatalysed Dynamic Kinetic Resolution of α-Thionitriles
Lauder, Kate,Anselmi, Silvia,Finnigan, James D.,Qi, Yuyin,Charnock, Simon J.,Castagnolo, Daniele
supporting information, p. 10422 - 10426 (2020/07/24)
The enantioselective synthesis of α-thiocarboxylic acids by biocatalytic dynamic kinetic resolution (DKR) of nitrile precursors exploiting nitrilase enzymes is described. A panel of 35 nitrilase biocatalysts were screened and enzymes Nit27 and Nit34 were found to catalyse the DKR of racemic α-thionitriles under mild conditions, affording the corresponding carboxylic acids with high conversions and good-to-excellent ee. The ammonia produced in situ during the biocatalytic transformation favours the racemization of the nitrile enantiomers and, in turn, the DKR without the need of any external additive base.
Isothiourea-mediated one-pot synthesis of trifluoromethyl substituted 2-pyrones
Yeh, Pei-Pei,Daniels, David S. B.,Cordes, David B.,Slawin, Alexandra M. Z.,Smith, Andrew D.
supporting information, p. 964 - 967 (2014/03/21)
A one-pot isothiourea-mediated Michael addition/lactonization/thiol elimination cascade sequence for the formation of 4,6-disubstituted and 3,4,6-trisubstituted 2-pyrones from (phenylthio)acetic acids and α,β-unsaturated trifluoromethyl ketones is described. The synthesis of a COX-2 inhibitor and the wide-ranging derivatization of the 2-pyrone moiety to trifluoromethyl substituted aromatics and heteroaromatics is also disclosed.
Nonenzymatic dynamic kinetic resolution of α-(arylthio)- and α-(alkylthio)alkanoic acids
Yang, Xing,Birman, Vladimir B.
supporting information; experimental part, p. 5553 - 5555 (2011/07/09)
Dynamic solution: The title acids undergo dynamic kinetic resolution during an enantioselective esterification catalyzed by (S)-homobenzotetramisole ((S)-HBTM; see scheme). This method extends the scope of the carboxylic acid derivatives that are amenable to the nonenzymatic version of this transformation. Copyright
Kinetic resolution of α-substituted alkanoic acids promoted by homobenzotetramisole
Yang, Xing,Birman, Vladimir B.
supporting information; experimental part, p. 11296 - 11304 (2011/10/19)
A new method for catalytic nonenzymatic kinetic resolution of α-substituted alkanoic acids has been developed, which relies on their activation with DCC followed by enantioselective alcoholysis of the intermediate symm-anhydrides in the presence of the amidine-based catalyst homobenzotetramisole (HBTM). Moderate to excellent selectivity factors (s=5-96) have been obtained in the case of several classes of substrates, namely, α-aryl-, α-aryloxy/alkoxy-, α-halo-, α-azido-, and α-phthalimido-alkanoic acids. Under similar conditions, α-(arylthio/alkylthio)-alkanoic acids undergo dynamic kinetic resolution providing corresponding esters in up to 92 % ee and up to 93 % yield. Copyright
Trichosporon beigelli esterase (TBE): A versatile esterase for the resolution of economically important racemates
Koul, Surrinder,Koul, Jawahir Lal,Singh, Budh,Kapoor, Munish,Parshad, Rajinder,Manhas, Kuldeep S.,Taneja, Subhash C.,Qazi, Ghulam N.
, p. 2575 - 2591 (2007/10/03)
A hydrolase producing strain Trichosporon beigelli esterase (TBE) isolated from local cottage cheese in its native form has displayed versatility and high efficacy in the kinetic resolution of a wide range of economically important substrates, which include racemic secondary alcohols, such as 1-(6-methoxy-2-naphthyl)ethanol (E ～ 316), 1-(3,4-methylenedioxyphenyl) ethanol and pentanol (E ～ 180 and 156 resp.), and alkyl esters of carboxylic acids such as ibuprofen (E ～ 340), 2-(benzylthio)propanoic acid (E ～ 1000). In other substrates such as in the primary alcohol 2-(6-methoxy-2- naphthyl)propan-1-ol and carboxylic acids such as 2-(5-bromo-6-methoxy-2- naphthyl)propanoic acid, 2-(2-naphthyloxy)propanoic acid, and substituted 2-thiopropanoic acids, it displayed moderate to low selectivity. Commercial lipases such as CCL, PPL, and PSL were also used in the resolution of the substrates for comparative studies.
Ionic liquid as catalyst and reaction medium: A simple, convenient and green procedure for the synthesis of thioethers, thioesters and dithianes using an inexpensive ionic liquid, [pmIm]Br
Ranu, Brindaban C.,Jana, Ranjan
, p. 1811 - 1818 (2007/10/03)
An easily accessible and inexpensive room temperature ionic liquid, 1-pentyl-3-methylimidazolium bromide, [pmIm]Br efficiently catalyzes the reaction of alkyl halides or acyl halides with thiols without any solvent at room temperature leading to the synthesis of thioethers and thioesters in high yields. This reaction has also been extended for the preparation of dithianes and transthioetherification. The ionic liquid is recovered and recycled for subsequent runs.
Microbial deracemization of α-substituted carboxylic acids: Substrate specificity and mechanistic investigation
Kato, Dai-Ichiro,Mitsuda, Satoshi,Ohta, Hiromichi
, p. 7234 - 7242 (2007/10/03)
A new enzymatic method for the preparation of optically active α-substituted carboxylic acids is reported. This technique is called deracemization reaction, which provides us with a route to obtain the enantiomerically pure compounds, theoretically in 100% yield starting from the racemic mixture. This means that the synthesis of a racemate is almost equal to the synthesis of the optically active compound, and this concept is entirely different from the commonly accepted one in the asymmetric synthesis. Using the growing cell system of Nocardia diaphanozonaria JCM3208, racemates of 2-aryl- and 2-aryloxypropanoic acid are deracemized smoothly and (R)-form-enriched products are recovered in high chemical yield (>50%). In addition, using optically active starting compounds and deuterated derivatives as well as inhibitors, we have disclosed the fact that a new type of enzyme takes part in this biotransformation, and that the reaction proceeds probably via the same mechanism as that in rat liver.
2-(4-R-Phenoxy/phenylthio)alkanoic esters of l-lupinine
Sparatore, Anna,Sparatore, Fabio
, p. 169 - 174 (2007/10/03)
Considering the great pharmacological interest in phenoxy/phenylthioalkanoic esters of open-chain or cyclic aminoalcohols, a set of ten such esters of lupinine was prepared. Initially, their ability to displace [3H]QNB from rat brain preparation was investigated. With the exception of two, all the prepared esters exhibited good affinity to muscarinic receptors (on a non-selective basis), with pKi in the range 6.67-7.68.
Kinetics and mechanism of thermal gas-phase elimination of α-substituted carboxylic acids: Role of relative basicity of α-substituents and acidity of incipient proton
Al-Awadi, Nouria A.,Kaul, Kamini,El-Dusouqui, Osman M. E.
, p. 499 - 504 (2007/10/03)
2-Phenoxypropanoic acid together with five of its aryl derivatives, its phenylthio and its N-phenylamino analogues were pyrolyzed at 494-566 K. The reactions were homogeneous, polar and free from catalytic and radical pathways, and obeyed a first-order rate equation. The limits of the Arrhenius log A (s-1) and E (kJ mol-1) values obtained for these reactions averaged 11.98 ± 1.71 and 158.1 ± 17.4, respectively. Analysis of the pyrolysates showed the elimination products to be carbon monoxide, acetaldehyde and the corresponding phenol, thiophenol or aniline compounds. The pyrolysis of 2-phenoxy- and 2-(N-phenylamino)-1-propanol was also investigated over the temperature range 638-792 K. The kinetic results and products analysis lend support to a reaction pathway involving a five-membered cyclic polar transition state. Copyright
