- Enantioselective Total Synthesis of (+)-Heilonine
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Chemical transformations that rapidly and efficiently construct a high level of molecular complexity in a single step are perhaps the most valuable in total synthesis. Among such transformations is the transition metal catalyzed [2 + 2 + 2] cycloisomerization reaction, which forges three new C-C bonds and one or more rings in a single synthetic operation. We report here a strategy that leverages this transformation to open de novo access to the Veratrum family of alkaloids. The highly convergent approach described herein includes (i) the enantioselective synthesis of a diyne fragment containing the steroidal A/B rings, (ii) the asymmetric synthesis of a propargyl-substituted piperidinone (F ring) unit, (iii) the high-yielding union of the above fragments, and (iv) the intramolecular [2 + 2 + 2] cycloisomerization reaction of the resulting carbon framework to construct in a single step the remaining three rings (C/D/E) of the hexacyclic cevanine skeleton. Efficient late-stage maneuvers culminated in the first total synthesis of heilonine (1), achieved in 21 steps starting from ethyl vinyl ketone.
- Cassaidy, Kyle J.,Rawal, Viresh H.
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supporting information
p. 16394 - 16400
(2021/10/20)
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- HIV-1 PROTEASE INHIBITORS AND USES THEREOF
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Various embodiments of the present invention are directed to compounds of the formula (I) or a pharmaceutically acceptable salt, polymorph, prodrug, solvate or clathrate thereof, wherein X1, X2, X3, R1, R2, R11, and n are defined herein. These compounds are useful as inhibitors of HIV-1 protease and, as a result, are useful in the treatment of HIV infection.
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Paragraph 0080
(2016/04/26)
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- METHOD FOR MANUFACTURING OPTICALLY ACTIVE MENTHOL
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An object of the present invention is to provide a method for manufacturing an optically active menthol having fewer steps, which generates less environmentally polluting waste because a catalytic reaction is involved in all of the steps, and is capable of saving a production cost. The present invention relates to a method for manufacturing an optically active menthol, including the following steps: A-1) asymmetrically hydrogenating at least one of geranial and neral to thereby obtain an optically active citronellal, B-1) conducting a ring-closure reaction of the optically active citronellal in the presence of an acid catalyst to thereby obtain an optically active isopulegol, and C-1) hydrogenating the optically active isopulegol to thereby obtain an optically active menthol.
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Paragraph 0411; 0412; 0413
(2013/10/07)
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- CATALYST FOR ASYMMETRIC HYDROGENATION
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This invention aims at providing a catalyst for producing an optically active aldehyde or an optically active ketone, which is an optically active carbonyl compound, by carrying out selective asymmetric hydrogenation of an α,β-unsaturated carbonyl compound, particularly a catalyst which is insoluble in a reaction mixture for obtaining optically active citronellal which is useful as a flavor or fragrance, by carrying out selective asymmetric hydrogenation of citral, geranial or neral; and a method for producing a corresponding optically active carbonyl compound. The invention relates to a catalyst for asymmetric hydrogenation of an α,β-unsaturated carbonyl compound, which comprises a powder of at least one metal selected from metals belonging to Group 8 to Group 10 of the Periodic Table, or a metal-supported substance in which at least one metal selected from metals belonging to Group 8 to Group 10 of the Periodic Table is supported on a support, an optically active cyclic nitrogen-containing compound and an acid.
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Page/Page column 49
(2010/12/31)
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- PROCESSES FOR PREPARING JAK INHIBITORS AND RELATED INTERMEDIATE COMPOUNDS
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The present invention is related to processes for preparing chiral substituted pyrazolyl pyrrolo[2,3-d]pyrimidines of Formula III, and related synthetic intermediate compounds. The chiral substituted pyrazolyl pyrrolo[2,3-d]pyrimidines are useful as inhibitors of the Janus Kinase family of protein tyrosine kinases (JAKs) for treatment of inflammatory diseases, myeloproliferative disorders, and other diseases.
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Page/Page column 67-68
(2010/08/07)
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- Enantioselective synthesis of janus kinase inhibitor INCB018424 via an organocatalytic aza-michael reaction
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An enantioselective synthesis of INCB018424 via organocatalytic asymmetric aza-Michael addition of pyrazoles (16 or 20) to (E)-3- cyclopentylacrylaldehyde (23) using diarylprolinol silyl ether as the catalyst was developed. Michael adducts (R)-24 and (R)-27 were isolated in good yield and high ee and were readily converted to INCB018424.
- Lin, Qiyan,Meloni, David,Pan, Yongchun,Xia, Michael,Rodgers, James,Shepard, Stacey,Li, Mei,Galya, Laurine,Metcalf, Brian,Yue, Tai-N,Liu, Pingli,Zhou, Jiacheng
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supporting information; experimental part
p. 1999 - 2002
(2009/09/06)
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- Enantioselective reduction of ketones with borane catalyzed by cyclic β-amino alcohols prepared from proline
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New catalysts have been prepared from (S)- and (R)-proline and the asymmetric borane reduction of prochiral ketones using these catalysts has been studied. The secondary alcohols were obtained in 76-95% yield with 57-96% enantiomeric excesses.
- Demir, Ayhan S.,Mecitoglu, Idris,Tanyeli, Cihangir,Guelbeyaz, Volkan
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p. 3359 - 3364
(2007/10/03)
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