- Pyridyl-Acyl Hydrazone Rotaxanes and Molecular Shuttles
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We report on rotaxanes featuring a pyridyl-acyl hydrazone moiety on the axle as a photo/thermal-switchable macrocycle binding site. The pyridyl-acyl E-hydrazone acts as a hydrogen bonding template that directs the assembly of a benzylic amide macrocycle around the axle to form [2]rotaxanes in up to 85% yield; the corresponding Z-hydrazone thread affords no rotaxane under similar conditions. However, the E-rotaxane can be smoothly converted into the Z-rotaxane in 98% yield under UV irradiation. The X-ray crystal structures of the E- and Z-rotaxanes show different intercomponent hydrogen bonding patterns. In molecular shuttles containing pyridyl-acyl hydrazone and succinic amide ester binding sites, the change of position of the macrocycle on the thread can be achieved through a series of light irradiation and heating cycles with excellent positional integrity (>95%) and switching fidelity (98%) in each state.
- Leigh, David A.,Marcos, Vanesa,Nalbantoglu, Tugrul,Vitorica-Yrezabal, I?igo J.,Yasar, F. Tuba,Zhu, Xiaokang
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- Migratory Arylboration of Unactivated Alkenes Enabled by Nickel Catalysis
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An unprecedented arylboration of unactivated terminal alkenes, featuring 1,n-regioselectivity, has been achieved by nickel catalysis. The nitrogen-based ligand plays an essential role in the success of this three-component reaction. This transformation displays good regioselectivity and excellent functional-group tolerance. In addition, the incorporation of a boron group into the products provides substantial opportunities for further transformations. Also demonstrated is that the products can be readily transformed into pharmaceutically relevant molecules. Unexpectedly, preliminary mechanistic studies indicate that although the metal migration favors the α-position of boron, selective and decisive bond formation is favored at the benzylic position.
- Wang, Wang,Ding, Chao,Li, Yangyang,Li, Zheqi,Li, Yuqiang,Peng, Long,Yin, Guoyin
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p. 4612 - 4616
(2019/03/13)
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- Hydrogenated acridine derivative and its application
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The invention relates to the field of chemical synthesis, and particularly relates to a compound with the general formula being Y-L-X and an application of the compound serving as a calcium channel blocking agent or/and an acetylcholinesterase inhibitor. The compound with the general formula being Y-L-X can be used for adjusting calcium homeostasis and treating cardiovascular diseases, stroke or dementia.
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Paragraph 0144; 0145; 0146; 0147
(2016/10/08)
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- Development of dual-acting benzofurans for thromboxane A2 receptor antagonist and prostacyclin receptor agonist: Synthesis, structure-activity relationship, and evaluation of benzofuran derivatives
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Prostacyclin (PGI2) is an unstable, powerful endogenous inhibitor of platelet aggregation, and thromboxane A2 (TXA 2) is an unstable endogenous arachidonic acid metabolite that plays a pivotal role in platelet aggregation and vasoconstriction. The balance between TXA2 and PGI2 greatly affects maintenance of the homeostasis of the circulatory system. A novel series of benzofuran-7- yloxyacetic acid derivatives was discovered as potent dual-acting agents to block the thromboxane A2 receptor and to activate the prostacyclin receptor. Synthesis, structure-activity relationship, and in vitro and ex vivo pharmacology of this series of compounds are described. The most potent in the series was {3-[2-(1,1-diphenylethylsulfanyl)ethyl]-2-hydroxymethylbenzofuran-7- yloxy}acetic acid diethanolamine salt (7) with Ki of 4.5 nM for thromboxane receptor antagonism and Ki of 530 nM for prostacyclin receptor agonism. Remarkably, compound 7 is a promising candidate for novel treatment as an antithrombotic agent with other cardiovascular actions to avoid hypotensive side effects.
- Ohno, Michihiro,Miyamoto, Mitsuko,Hoshi, Kazuhiro,Takeda, Takahiro,Yamada, Naohiro,Ohtake, Atsushi
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p. 5279 - 5294
(2007/10/03)
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- Synthesis of N-glyoxyl prolyl and pipecolyl amides and thioesters and evaluation of their in vitro and in vivo nerve regenerative effects
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The recent discovery that small molecule ligands for the peptidyl-prolyl isomerase (PPIase) FKBP12 possess powerful neuroprotective and neuroregenerative properties in vitro and in vivo suggests therapeutic utility for such compounds in neurodegenerative disease. The neurotrophic effects of these compounds are independent of the immunosuppressive pathways by which drugs such as FK506 and rapamycin operate. Previous work by ourselves and other groups exploring the structure-activity relationships (SAR) of small molecules that mimic only the FKBP binding domain portion of FK506 has focused on esters of proline and pipecolic acid. We have explored amide and thioester analogues of these earlier structures and found that they too are extremely potent in promoting recovery of lesioned dopaminergic pathways in a mouse model of Parkinson's disease. Several compounds were shown to be highly effective upon oral administration after lesioning of the dopaminergic pathway, providing further evidence of the potential clinical utility of a variety of structural classes of FKBP12 ligands.
- Hamilton, Gregory S.,Wu, Yong-Qian,Limburg, David C.,Wilkinson, Douglas E.,Vaal, Mark J.,Li, Jia-He,Thomas, Christine,Huang, Wei,Sauer, Hansjorg,Ross, Douglas T.,Soni, Raj,Chen, Yi,Guo, Hongshi,Howorth, Pamela,Valentine, Heather,Liang, Shi,Spicer, Dawn,Fuller, Mike,Steiner, Joseph P.
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p. 3549 - 3557
(2007/10/03)
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- The conversion of alcohols to halides using a filterable phosphine source
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The conversion of primary and secondary alcohols to chlorides and bromides using 1,2-bis(diphenylphosphino)ethane (diphos) is described. Use of this reagent in lieu of the typical triphenylphosphine-carbontetrahalide complex provides a facile means of purifying the desired halide from the phosphine-oxide byproduct.
- Pollastri, Michael P.,Sagal, John F.,Chang, George
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p. 2459 - 2460
(2007/10/03)
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- Novel reductive Friedel-Crafts alkylation of aromatics catalyzed by indium compounds: Chemoselective utilization of carbonyl moieties as alkylating reagents
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Reductive Friedel-Crafts alkylation of aromatics with ketones or aldehydes was characteristically catalyzed by indium compounds in preference to general catalysts like AlCl3 and BF3, where hydrosilanes would play an important role both as a hydride donor and as a co-catalyst. Chemoselective utilization of ketone moieties as alkylating reagents took place even in the presence of halogen, ester or ether moieties which are very susceptible under traditional Friedel-Crafts conditions. Discussion on a plausible intermediate was carried out by some controlled experiments.
- Miyai, Takashi,Onishi, Yoshiyuki,Baba, Akio
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p. 1017 - 1026
(2007/10/03)
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- New Prenylamine analogues: synthesis and Ca2+-entry blocking activity
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The synthesis of a series of diphenylalkylamine derivatives related to prenylamine is reported.The amphetamine group in the prenylamine structure was replaced by other moieties.In addition to substitutions in the aromatic rings, heteroatoms such as sulphur and oxygen were introduced in the chain.The calcium-entry blocking activity was assayed in binding experiments on a guinea-pig brain membrane preparation by displacing -nitrendipine.
- Caldirola, PM,Goot, H van der,Timmerman, H
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p. 571 - 579
(2007/10/02)
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- Carbanion Rearrangements by Intramolecular 1,ω Proton Shifts, IV. The Reaction of ω,ω-Diphenylalkyllithium Compounds: Proof for an Intramolecular Transmetallation Reaction by Crossover Experiments Using Isotopic Labelled Starting Material
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3,3-Diphenylpropyllithium (2) and 2-(9-fluorenyl)ethyllithium (43) do not show a 1,3 proton shift but splitt off ethylene.On the other hand 4,4-diphenylbutyllithium (19) in diethyl ether can be forced to rearrange to 1,1-diphenylbutyllithium (18) by the addition of THF.The half reaction time for this 1,4 proton shift was found to be about 4 minutes.Proof for the intramolecular character of this transmetallation reaction was obtained by crossover experiments with specifically deuterated starting material.The 1,5 proton shift with 5,5-diphenylpentyllithium (12) occurs considerably slower than the 1,4 shift with 4,4-diphenylbutyllithium (19).The rearrangement also takes place in pure diethyl ether although with a half reaction time of about 2 days.Only 3-(9-fluorenyl)propyllithium (41) in diethyl ether spontaneously shows rearrangement already at -30 deg C, whereby 9-propyl-9-fluorenyllithium (42) is formed by a 1,4 proton shift.A 1,ω phenyl migration according to Grovenstein-Zimmerman in no case could be observed.
- Maercker, Adalbert,Passlack, Michael
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p. 710 - 723
(2007/10/02)
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- Synthesis and Cardiovascular Activity of a New Series of Cyclohexylaralkylamine Derivatives Related to Perhexiline
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A series of 24 cyclohexylaralkylamine derivatives related to perhexilene has been synthesized and screened for cardiovascular activity.All the compounds contained an exocyclic amine which was substituted either by an alkyl, cycloalkyl, or aralkyl group.In the hope of further reducing toxicity, the synthesis of p-tolyl- and p-hydroxyphenyl derivatives 23 and 24 was undertaken.The effect of separating the cyclohexylamine moiety with respect to the aromatic nucleus has been systematically examined.The pharmacological investigations were directed to a search for compounds having an activity better than perhexiline according to the following order of criteria: (1) α-adrenolytic activity; (2) increase of coronary blood flow; (3) calcium antagonism.Several compounds were more potent and exhibited lower toxicity than perhexiline.Further detailed pharmacological investigations (tension time index and decreased cardiac work) have led to the selection of N,2-dicyclohexyl-2-phenethylamine (3) for clinical trials, which are now under way.
- Leclerc, Gerard,Decker, Nicole,Schwartz, Jean
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p. 709 - 714
(2007/10/02)
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