14738-25-1Relevant academic research and scientific papers
Cu(I)/chiral bisoxazoline-catalyzed enantioselective sommelet-hauser rearrangement of sulfonium ylides
Wang, Jianbo,Li, Shu-Sen
supporting information, p. 12343 - 12358 (2020/11/10)
Catalytic asymmetric thia-Sommelet-Hauser rearrangement of sulfonium ylides remains a great challenge due to its multistep reaction mechanism involving metal carbene formation, proton transfer, and [2,3]-sigmatropic rearrangement. In particular, the key problem of such reactions is the differentiation of the enantiotopic lone pair electrons of sulfur, which generates the sulfonium ylide intermediate bearing chirality on the sulfur atom. With a modified chiral bisoxazoline ligand, we developed a Cu(I)- catalyzed asymmetric thia-Sommelet-Hauser rearrangement with good to excellent enantioselectivities. Mechanistic studies provide insights into the details of the reaction mechanism.
MYOGLOBIN-BASED CATALYSTS FOR CARBENE TRANSFER REACTIONS
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Paragraph 00308; 00312; 00316, (2016/06/14)
Methods are provided for carrying out carbene transfer transformations such as olefin cyclopropanation reactions, carbene heteroatom-H insertion reactions (heteroatom = N, S, Si), sigmatropic rearrangement reactions, and aldehyde olefination reactions with high efficiency and selectivity by using a novel class of myoglobin-based biocatalysts. These methods are useful for the synthesis of a variety of organic compounds which contain one or more new carbon-carbon or carbon-heteroatom (N, S, or Si) bond. The methods can be applied for conducting these transformations in vitro (i.e., using the biocatalyst in isolated form) and in vivo (i.e., using the biocatalyst in a whole cell system).
Intermolecular carbene S-H insertion catalysed by engineered myoglobin-based catalysts
Tyagi, Vikas,Bonn, Rachel B.,Fasan, Rudi
, p. 2488 - 2494 (2015/03/30)
The first example of a biocatalytic strategy for the synthesis of thioethers via an intermolecular carbene S-H insertion reaction is reported. Engineered variants of sperm whale myoglobin were found to efficiently catalyze this C-S bond forming transformation across a diverse set of aryl and alkyl mercaptan substrates and α-diazoester carbene donors, providing high conversions (60-99%) and high numbers of catalytic turnovers (1100-5400). Furthermore, the enantioselectivity of these biocatalysts could be tuned through mutation of amino acid residues within the distal pocket of the hemoprotein, leading to myoglobin variants capable of supporting asymmetric S-H insertions with up to 49% ee. Rearrangement experiments support a mechanism involving the formation of a sulfonium ylide generated upon attack of the thiol substrate to a heme-bound carbene intermediate. This journal is
Copper-Catalyzed Synthesis of α-Thioaryl Carbonyl Compounds Through S-S and C-C Bond Cleavage
Zou, Liang-Hua,Priebbenow, Daniel L.,Wang, Long,Mottweiler, Jakob,Bolm, Carsten
supporting information, p. 2558 - 2563 (2013/10/21)
A method to access α-thioaryl ketones and α-thioaryl esters employing copper acetate (hydrate) as catalyst and readily accessible diaryl disulfides and β-diketones (or β-keto esters) has been developed. Both alkyl- and aryl-substituted carbonyl compounds can be prepared. Copyright
An efficient synthesis of aryloxyacetic acid and arylthioacetic acid esters
Li, Ji-Tai,Li, Hong-Ya,Li, Hui-Zhang
, p. 416 - 417 (2007/10/03)
The esterification of the aryloxyacetic acid and arylthioacetic acid catalysed by silica sulfuric acid results aryloxyacetic acid and arylthioacetic acid ester in 83-94% yields respectively under mild reaction conditions.
Studies in the Cycloproparene Series: Reactions with Radicals
Chai, Christina L. L.,Christen, Detlev,Halton, Brian,Neidlein, Richard,Starr, Malcolm A. E.
, p. 577 - 592 (2007/10/02)
The behaviour of 1H-cyclopropabenzene (1) and 1H-cyclopropanaphthalene (23) towards a variety of radicals results in opening of the three-membered ring to give ortho-substituted benzyl and 2-methylnaphthalene derivatives, e.g. (13) and (28), respectively.Ring expansion into the cycloheptatriene manifold by way of addition to the bridge bond and norcaradiene formation have not been observed.Analogous reactions with the methylidenecyclopropanaphthalenes (33) and (34) lead to much decomposition, and provide little evidence for the C 1 cycloproparenyl radicals (35) and (36).
Kinetics and Mechanism of Oxidation of Ethyl Phenylthioacetates by Bromamine-B
Gurumurthy, Rajagopal,Sathiyanarayanan, Kulathu Iyer,Gopalakrishnan, Mannathusamy
, p. 1096 - 1100 (2007/10/02)
The kinetics of oxidation of several substituted ethyl phenylthiacetates by bromamine-B (sodium salt of N-bromobenzenesulfonamide) has been studied in 50percent (v/v) aqueous ethanol medium.Disodium hydrogenphosphate and sodium dihydrogenphosphate buffer
