21622-01-5Relevant articles and documents
New synthesis of 3-cyclopentenecarboxylic acid esters by olefin metathesis
Bespalova, N. B.,Bovina, M. A.,Sergeeva, M. B.,Zaikin, V. G.
, p. 1425 - 1426 (1994)
Olefin metathesis of diallylacetic acid esters is proposed for the synthesis of 3-cyclopentenecarboxylic acid esters.WCl6-organosilicon compounds are used as homogeneous catalysts. - Key words: olefin metathesis, 3-cyclopentenecarboxylic acid esters, homogeneous silicon-containing catalysts.
Practical and Scalable Synthesis of a Glucokinase Activator via One-Pot Difluorination and Julia Olefination
Inoshita, Yasuo,Iwamoto, Minoru,Koyama, Yuzo,Kumamoto, Takuya,Miyamoto, Hidetoshi,Sakumoto, Chihiro,Sato, Yoshinori,Tamamizu, Tokihiko,Tsuchiya, Hideyoshi
, p. 1294 - 1303 (2020/08/14)
We describe the process research and development of a practical synthesis of glucokinase activator 1 as a potential drug for treating type 2 diabetes mellitus. The key structure, a 3,4-cis-difluorinated cyclopentane moiety, was constructed via diastereoselective epoxidation, followed by one-pot difluorination with Et3N·3HF and perfluorobutanesulfonyl fluoride (PBSF). Julia olefination of benzothiazol-2-yl sulfone with glyoxylate furnished an E/Z mixture of acrylate, followed by isomerization of the alkene to the desired E configuration during the formation of the acid chloride in the final step. This development achieved a highly practical process route to 1 (15percent overall yield, 12 steps). This process route overcomes the drawbacks of the original medicinal chemistry synthetic route, which used hazardous and costly reagents (LiAlH4, OsO4, and Deoxo-Fluor) and had low efficiency (4percent overall yield, 20 steps).
Molybdenum Benzylidyne Complexes for Olefin Metathesis Reactions
Acosta, Carlos M.,Bukhryakov, Konstantin V.,Chuprun, Sergey,Mathivathanan, Logesh
supporting information, p. 3453 - 3457 (2020/11/02)
The molybdenum benzylidynes [ArCMo(OC(CF3)2CH3)3(1,2-dimethoxyethane)], where Ar = Ph (2a), p-(OCH3)C6H4 (2b), p-(CF3)C6H4 (2c), p-(NO2)C6H4 (2d), or 4-(NO2)-3-(CF3)C6H3 (2e), and [p-(NO2)C6H4CMo(OC(CF3)2CH3)3] (2f) catalyze the ring-closing metathesis (RCM) reaction of diallyl N-tosylamide (3) to produce 1-tosyl-2,5-dihydro-1H-pyrrole (4) and ethylene. The scope of RCM catalytic activity of 2e, cross-metathesis of 1-hexene, and ring-opening metathesis polymerization of cyclooctene were explored. The X-ray crystal structure of 2e was determined. Variable-temperature 1H NMR spectra revealed the formation of intermediates during the reaction of 3 with 2f and the reforming of 2f after completion of the reaction. The use of 13C-labeled Mo benzylidyne did not show transfer of the carbon atom next to Mo to any of the products.
SUBSTITUTED CYCLOPENTANE-AMIDES FOR TREATING DISORDERS RELATED TO RET
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Paragraph 00206; 00207; 00208, (2018/03/01)
Described herein are compounds that inhibit wild-type RET and its resistant mutants, pharmaceutical compositions including such compounds, and methods of using such compounds and compositions.
2′-fluoronucleosides
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Page/Page column 57; 58, (2015/11/30)
2′-Fluoro-nucleoside compounds are disclosed which are useful in the treatment of hepatitis B infection, hepatitis C infection, HIV and abnormal cellular proliferation, including tumors and cancer. The compounds have the general formulae: wherein Base is a purine or pyrimidine base;R1 is OH, H, OR3, N3, CN, halogen, CF3, lower alkyl, amino, loweralkylamino, di(lower)alkylamino, or alkoxy;R2 is H, phosphate, or a stabilized phosphate prodrug; acyl, or other pharmaceutically acceptable leaving benzyl, a lipid, an amino acid, peptide, or cholesterol; andR3 is acyl, alkyl, phosphate, or other pharmaceutically acceptable leaving group; or a pharmaceutically acceptable salt thereof.
A broadly applicable and practical oligomeric (salen)Co catalyst for enantioselective epoxide ring-opening reactions
White, David E.,Tadross, Pamela M.,Lu, Zhe,Jacobsen, Eric N.
, p. 4165 - 4180 (2014/06/09)
The (salen)Co catalyst (4a) can be prepared as a mixture of cyclic oligomers in a short, chromatography-free synthesis from inexpensive, commercially available precursors. This catalyst displays remarkable enhancements in reactivity and enantioselectivity relative to monomeric and other multimeric (salen)Co catalysts in a wide variety of enantioselective epoxide ring-opening reactions. The application of catalyst 4a is illustrated in the kinetic resolution of terminal epoxides by nucleophilic ring-opening with water, phenols, and primary alcohols; the desymmetrization of meso epoxides by addition of water and carbamates; and the desymmetrization of oxetanes by intramolecular ring opening with alcohols and phenols. The favorable solubility properties of complex 4a under the catalytic conditions facilitated mechanistic studies, allowing elucidation of the basis for the beneficial effect of oligomerization. Finally, a catalyst selection guide is provided to delineate the specific advantages of oligomeric catalyst 4a relative to (salen)Co monomer 1 for each reaction class.
Desymmetrization of cyclic olefins via asymmetric Heck reaction and hydroarylation
Liu, Sijia,Zhou, Jianrong
supporting information, p. 11758 - 11760 (2013/12/04)
An asymmetric Heck reaction allows desymmetrization of substituted cyclic olefins in high dr and ee. A bisphosphine oxide is uniquely stereoselective for this purpose. Desymmetrization of bicyclic olefins via hydroarylation can also be realized in high ee.
SUBSTITUTED DIAMINOCARBOXAMIDE AND DIAMINOCARBONITRILE PYRIMIDINES, COMPOSITIONS THEREOF, AND METHODS OF TREATMENT THEREWITH
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Page/Page column 200, (2012/11/07)
Provided herein are Diaminopyrimidine Compounds having the following structures: wherein R1, R2, R3, and R4 are as defined herein, compositions comprising an effective amount of a Diaminopyrimidine Compound, and methods for treating or preventing liver fibrotic disorders or a condition treatable or preventable by inhibition of a JNK pathway.
Combination of olefin metathesis and enzymatic ester hydrolysis in aqueous media in a one-pot synthesis
Tenbrink, Katharina,Sessler, Miriam,Schatz, Juergen,Groeger, Harald
scheme or table, p. 2363 - 2367 (2011/10/13)
A new synthetic method for the preparation of cyclic malonic acid monoesters in aqueous media was developed based on the combination of a metathesis reaction and subsequent biocatalytic hydrolysis with a pig liver esterase in a one-pot synthesis. Both reaction steps proceed smoothly under optimized conditions in aqueous media requiring only a low amount of the metal catalyst for the metathesis reaction. Notably, the applied biocatalyst turned out to be highly compatible with the metal catalyst showing no significant influence on the enzyme activity. Copyright
Polymorphic Forms of Dolasetron Base and Processes of Preparing Dolasetron Base, Its Polymorphic Forms and Salt Thereof
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Page/Page column 10, (2008/12/08)
The present disclosure relates to a process for the preparation of endo-hexahydro-8-(3-indolylcarbonyloxy)-2,6-methano-2H-quinolizin-3(4H)-one or Dolasetron base. It also discloses a process for the preparation of endo-hexahydro-8-(3-indolylcarbonyloxy)-2,6-methano-2H-quinolizin-3(4H)-one mesylate or Dolasetron mesylate. Further, the present disclosure relates to a process for producing Form I of Dolasetron base, and to the novel crystalline polymorphs, Form II, III, IV and V of Dolasetron base and industrial processes for producing them.
