- Organocatalytic enantioselective sulfur-michael addition of thioacetic acid to arylmethylidenemalonates
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An organocatalytic enantioselective sulfur-Michael addition of thioacetic acid to arylmethyli-denemalonates was developed with high yields and up to 97% enantiomeric excess. Both enantiomers of the products were accessible with two different organocatalys
- Wang, Renchao,Liu, Jing,Xu, Jiaxi
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- Synthesis of macrocyclic and medium-sized ring thiolactonesviathe ring expansion of lactams
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A side chain insertion method for the ring expansion of lactams into macrocyclic thiolactones is reported, that can also be incorporated into Successive Ring Expansion (SuRE) sequences. The reactions are less thermodynamically favourable than the analogous lactam- and lactone-forming ring expansion processes (with this notion supported by DFT data), but nonetheless, three complementary protecting group strategies have been developed to enable this challenging transformation to be achieved.
- Palate, Kleopas Y.,Epton, Ryan G.,Whitwood, Adrian C.,Lynam, Jason M.,Unsworth, William P.
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supporting information
p. 1404 - 1411
(2021/02/27)
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- Green method for synthesizing high value-added mercaptoacid by catalyzing addition reaction of H2S and olefine acid by using ionic liquid as catalyst
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The invention relates to a green method integrating catalysis, reaction and separation, which is used for producing beta-mercapto carboxylic acid through addition of alpha, beta-unsaturated carboxylic acid and H2S by taking amino-functionalized hydrophobic ionic liquid as a catalyst. H2S is activated through tertiary amine alkaline sites contained in the ionic liquid, so that H2S and double bonds of alpha, beta-unsaturated carboxylic acid are subjected to an addition reaction, and recycling of H2S is realized. The product obtained after the reaction can be subjected to water phase liquid-liquid extraction to realize separation of the catalyst and the product, and the ionic liquid can be recycled. In the system, the ionic liquid is both a catalytic medium and a reaction medium, no other organic solvent participates in the system, H2S is efficiently utilized, meanwhile, high-added-value products such as mercapto acid are obtained, and the method is more economical and environmentally friendly and conforms to the development concept of green chemical industry.
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Paragraph 0041; 0049-0050; 0053-0054; 0060-0062
(2021/05/05)
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- Ruthenium(II)–Arene Thiocarboxylates: Identification of a Stable Dimer Selectively Cytotoxic to Invasive Breast Cancer Cells
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RuII-arene complexes provide a versatile scaffold for novel anticancer drugs. Seven new RuII-arene-thiocarboxylato dimers were synthesized and characterized. Three of the complexes (2 a, b and 5) showed promising antiproliferative activities in MDA-MB-231 (human invasive breast cancer) cells, and were further tested in a panel of fifteen cancerous and noncancerous cell lines. Complex 5 showed moderate but remarkably selective activity in MDA-MB-231 cells (IC50=39±4 μm Ru). Real-time proliferation studies showed that 5 induced apoptosis in MDA-MB-231 cells but had no effect in A549 (human lung cancer, epithelial) cells. By contrast, 2 a and b showed moderate antiproliferative activity, but no apoptosis, in either cell line. Selective cytotoxicity of 5 in aggressive, mesenchymal-like MDA-MB-231 cells over many common epithelial cancer cell lines (including noninvasive breast cancer MCF-7) makes it an attractive lead compound for the development of specifically antimetastatic Ru complexes with low systemic toxicity.
- Stephens, Liam J.,Levina, Aviva,Trinh, Iman,Blair, Victoria L.,Werrett, Melissa V.,Lay, Peter A.,Andrews, Philip C.
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p. 1188 - 1200
(2019/12/24)
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- POLYMERIZATION ACCELERATOR, CURABLE COMPOSITION, CURED PRODUCT, AND PROCESS FOR PRODUCING THIOL COMPOUND
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A polymerization accelerator includes a specific thiol compound. A curable composition of excellent thermal stability contains the polymerization accelerator. A cured product is obtained from the curable composition. The polymerization accelerator includes a thiol compound having two or more groups represented by Formula (1) below: wherein R1 is a hydrogen atom or a C1-10 alkyl group, and m is an integer of 0, 1 or 2.
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Page/Page column 7-8
(2010/03/02)
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- METHOD OF PRODUCING β-MERCAPTOCARBOXYLIC ACIDS
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The invention relates to a method for efficiently producing β-mercaptocarboxylic acids using a solid acid catalyst such as zeolite, which product corresponds to respective starting materials selected from α, β-unsaturated carboxylic acids (α, β-unsaturated carboxylic acid, a, β-unsaturated carboxylic acid ester, ex, β-unsaturated amide, a, β-unsaturated aldehide and α, β-unsaturated ketone) and hydrogen sulfides (hydrogen sulfide, sulfide salt and hydrosulfide salt), wherein a solvent compatible with water is used in the reaction. According to the invention, β-mercaptocarboxylic acids which are useful as additives in synthetic materials for pharmaceutical or agricultural agents and in polymer compounds can be industrially produced efficiently by using easily available a, β-unsaturated carboxylic acid (such as crotonic acid) at high yield.
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Page/Page column 31-32
(2009/04/25)
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- Influence of Nucleophiles on the High Temperature Aqueous Isomerization of cis- to trans-Cinnamic Acid
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The rate of isomerization of cis- to trans-cinnamic acid in water at 195 deg C was monitored as a function of added nucleophile.The expected nucleophile addition products were not observed but could be synthesized and, when subjected to the reaction conditions, rapidly converted to trans-cinnamic acid.Deuterium labeling studies indicated that proton abstraction was not the rate-determining step, that the α-deuterium of α,β-dideuterio-cis-cinnamic acid was rapidly exchanged for an α-hydrogen atom without loss of the cis geometry, and that some direct isomerization of cis- to trans-cinnamic acid occured without the loss of vinyl deuterium atoms.The isomerization appears to involve an addition-elimination mechanism in the case of HO(1-) and HS(1-) ions, with the former more effective.Anthrahydroquinone ion was quite effective, meaning that it was a superior nucleophile or was promoting reactions by another mechanism (possibly electron tranfer chemistry).The results have bearing on the rate-determining step in one of the delignification mechanisms occurring during the pulping of wood.
- Reed, Gregg A.,Dimmel, Donald R.,Malcolm, Earl W.
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p. 6364 - 6371
(2007/10/02)
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