- Zn-Catalyzed Enantio- and Diastereoselective Formal [4 + 2] Cycloaddition Involving Two Electron-Deficient Partners: Asymmetric Synthesis of Piperidines from 1-Azadienes and Nitro-Alkenes
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We report a catalytic asymmetric synthesis of piperidines through [4 + 2] cycloaddition of 1-azadienes and nitro-alkenes. The reaction uses earth abundant Zn as catalyst and is highly diastereo- and regioselective. A novel BOPA ligand (F-BOPA) confers high reactivity and enantioselectivity in the process. The presence of ortho substitution on the arenes adjacent to the bis(oxazolines) was found to be particularly impactful, due to limiting the undesired coordination of 1-azadiene to the Lewis acid and thus allowing the reaction to be carried out at lower temperature. A series of secondary kinetic isotope effect studies using a range of ligands implicates a stepwise mechanism for the transformation, involving an initial Michael-type addition of the imine to the nitro-alkene followed by a cyclization event. The stepwise mechanism obviates the electronic requirement inherent to a concerted mechanism, explaining the successful cycloaddition between two electron-deficient partners. (Chemical Equation Presented).
- Chu, John C. K.,Dalton, Derek M.,Rovis, Tomislav
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p. 4445 - 4452
(2015/04/14)
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- Synthesis and structure-activity studies of the V-ATPase inhibitor saliphenylhalamide (SaliPhe) and simplified analogs
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An efficient total synthesis of the potent V-ATPase inhibitor saliphenylhalamide (SaliPhe), a synthetic variant of the natural product salicylihalamide A (SaliA), has been accomplished aimed at facilitating the development of SaliPhe as an anticancer and antiviral agent. This new approach enabled facile access to derivatives for structure-activity relationship studies, leading to simplified analogs that maintain SaliPhe's biological properties. These studies will provide a solid foundation for the continued evaluation of SaliPhe and analogs as potential anticancer and antiviral agents.
- Garcia-Rodriguez, Jose,Mendiratta, Saurabh,White, Michael A.,Xie, Xiao-Song,De Brabander, Jef K.
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supporting information
p. 4393 - 4398
(2015/10/12)
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- NOVEL COMPOUNDS AS CHLORIDE CHANNEL BLOCKING AGENT
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Disclosed is a novel compound to function as a calcium-dependent chloride channel blocking agent.
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Paragraph 0325; 0326; 0327; 0328; 0329
(2015/06/03)
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- Derivatives of 2-(substituted sulfamyl)-6-nitrobenzoic acids, useful as adjuncts to radiation therapy
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Derivatives of 2-(Substituted sulfamyl) 6-nitrobenzoic acids are disclosed, wherein at least one of the sulfamyl substituents is selected from amino-(lower alkyl), (lower alkyl)-amino-(lower alkyl), or di(lower alkyl)-amino-(lower alkyl), hydrogen, lower
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- 2-(substituted sulfamyl)-6-nitrobenzoic acid amides and pharmaceutical compositions
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2-(Substituted sulfamyl) derivatives of 6-nitrobenzoic acid wherein at least one of the sulfamyl substituents is a basic substituent selected from amino-(lower alkyl), (lower alkyl)-amino-(lower alkyl), or di(lower alkyl)-amino-(lower alkyl) are disclosed
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- Esters of 2-(substituted sulfamyl)-6-nitro-benzoic acid and pharmaceutical compositions
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Amides and esters of 2-(substituted sulfamyl)-6-nitro-benzoic acid, in which the substituents on the sulfamyl nitrogen are non-basic, such as: hydrogen, alkyl, hydroxyalkyl and non-basic heterocycles, which are useful as adjuncts to radiation therapy.
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- Derivatives of 2-(substituted sulfamyl)-6-nitrobenzoic acids and pharmaceutical compositions
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Derivatives of 2-(substituted sulfamyl) 6-nitrobenzoic acids are disclosed, wherein at least one of the sulfamyl substituents is selected from amino-(lower alkyl), (lower alkyl)-amino-(lower alkyl), or di(lower alkyl)-amino-(lower alkyl), hydrogen, lower
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