- Beyond Chemoselectivity: Catalytic Site-Selective Aldolization of Diketones and Exploitation for Enantioselective Alzheimer's Drug Candidate Synthesis
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Site selectivity, differentiating instances of the same functional group type on one substrate, represents a forward-looking theme within chemistry: reduced dependence on protection/deprotection protocols for increased overall yield and step-efficiency. Despite these potential benefits and the expanded tactical advantages afforded to synthetic design, site selectivity remains elusive and especially so for ketone-based substrates. Herein, site-selective intermolecular mono-aldolization has been demonstrated for an array of prochiral 4-keto-substituted cyclohexanones with concomitant regio-, diastereo-, and enantiocontrol. Importantly, the aldol products allow rapid access to molecularly complex ketolactones or keto-1,3-diols, respectively containing three and four stereogenic centers. The reaction conditions are of immediate practical value and general enough to be applicable to other reaction types. These findings are applied in the first enantioselective, formal, synthesis of a leading Alzheimer's research drug, a γ-secretase modulator (GSM), in the highest known yield.
- Nugent, Thomas C.,Najafian, Foad Tehrani,Hussein, Hussein Ali El Damrany,Hussain, Ishtiaq
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p. 14342 - 14348
(2016/09/23)
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- Discovery and optimization of piperidyl benzamide derivatives as a novel class of 11β-HSD1 inhibitors
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Discovery and optimization of a piperidyl benzamide series of 11β-HSD1 inhibitors is described. This series was derived from a cyclohexyl benzamide lead structures to address PXR selectivity, high non-specific protein binding, poor solubility, limited in
- Rew, Yosup,McMinn, Dustin L.,Wang, Zhulun,He, Xiao,Hungate, Randall W.,Jaen, Juan C.,Sudom, Athena,Sun, Daqing,Tu, Hua,Ursu, Stefania,Villemure, Elisia,Walker, Nigel P.C.,Yan, Xuelei,Ye, Qiuping,Powers, Jay P.
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scheme or table
p. 1797 - 1801
(2009/12/07)
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- Sulphonamide derivatives
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The present invention provides novel sulphonamide derivatives which are useful for potentiating glutamate receptor function in a mammal requiring treatment, processes for their preparation, and pharmaceutical compositions containing them.
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- Synthesis of 3- and 4-Substituted Cyclic α-Amino Acids Structurally Related to ACPD
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The preparation of 3-substituted cyclopentanones 12-16, 4-substituted cyclohexanones 23-28 and cycloheptanones 38-41 is described.Substituents in the cycloalkanones are carboxylate, phosphonate or tetrazole groups, separated from the ring by a 0, 1, 2, or 3 carbon atoms chain.These cycloalkanones have been transformed into α-amino acids 9-11 by hydrolysis of the corresponding hydantoin derivatives 21, 37 and 62, obtained under Bucherer-Bergs reaction conditions.
- Alonso, Francisco,Mico, Irene,Najera, Carmen,Sansano, Jose M.,Yus, Miguel,et al.
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p. 10259 - 10280
(2007/10/02)
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- Substituted Benzamides with Conformationally Restricted Side Chains. 5. Azabicyclo Derivatives as 5-HT4 Receptor Agonists and Gastric Motility Stimulants
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The syntheses of benzamides containing azabicyclo side chains and their 5-HT4 receptor agonist and 5-HT3 receptor antagonist properties are described.These compounds were designed to mimic higher energy conformations of quinol
- King, Frank D.,Hadley, Michael S.,Joiner, Karen T.,Martin, Roger T.,Sanger, Gareth J.,et al.
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p. 683 - 689
(2007/10/02)
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- Drastic ring transformation reactions of fused bicyclic rings to bridged bicyclic rings
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By treatment with BF3-etheratelethylene glycol, cyclohexanone with a carbonyl function at the 2′-(or 3′-) position of γ-side chain underwent novel ring transformation to afford five- (or six-) membered rings, and the fused bicyclic rings (bicyc
- Yamamoto, Takayoshi,Eki, Toshiko,Nagumo, Shinji,Suemune, Hiroshi,Sakai, Kiyoshi
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p. 4517 - 4524
(2007/10/02)
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