- Synthesis of Functionalized Cyclopropindenes via the Carbene Addition Route
-
The synthesis of 4,5-dihydro-1H,3H-cycloprop(f)inden-4-ol (1) and diethyl 4,5-dihydro-1H,3H-cyclopropindene-4,4-dicarboxylate 26 starting from diene 4 is described.The cyclopentene ring is constructed by condensation of diethyl malonate to the dibromide 21.The key-step in the synthesis of 1 consists in a twofold Curtius degradation of 22, with subsequent reduction of the carbonyl group and aromatization.The skeleton of the isomer 31 is synthesized via cycloaddition of butadiene to cyclopent-4-ene-1,3-dione (7) and addition of dichlorocarbene to the adduct 27 after ketalization.The attempted synthesis of dihydrocyclopropindene (2) by base-induced elimination of several appropriately substituted precursors failed.
- Mueller, Paul,Miao, Zhongshan
-
-
Read Online
- Copper(II)-catalyzed enantioselective intramolecular cyclization of N-alkenylureas
-
The first Cu(II)-catalyzed highly enantioselective intramolecular cyclization of N-alkenylureas was developed for the concise assembly of chiral vicinal diamino bicyclic heterocycles. Facile removal of carbonyl group of the carbamido moiety allowed for ready access to enantioenriched cyclic vicinal diamines.
- Fu, Shaomin,Yang, Honghao,Deng, Yuanfu,Jiang, Huanfeng,Zeng, Wei,Li, Guoqiang
-
supporting information
p. 1018 - 1021
(2015/03/30)
-
- Synthesis and hydrogen adsorption properties of internally polarized 2,6-azulenedicarboxylate based metal-organic frameworks
-
To improve the binding energy of hydrogen, incorporation of internally polarized organic units into metal-organic frameworks (MOFs) should be a promising strategy. In this study, two novel MOFs composed of internally polarized 2,6-azulenedicarboxylate (2,6-azd), termed MOF-649 [Zn2(2,6-azd)2(dabco), where dabco = 1,4-diazabicyclo[2.2.2]octane] and MOF-650 [Zn4O(2,6-azd)3], have been synthesized, and their crystal structures were determined by single-crystal X-ray diffraction analyses. Both materials displayed permanent microporosity, and the Brunauer-Emmett-Teller (BET) surface areas of MOF-649 and MOF-650 are estimated to be 910 and 2630 m2 g-1, respectively. The H2 adsorption measurements showed that MOF-650 adsorbs 14.8 mg g-1 of hydrogen at 77 K and 1 bar. The polarization effect of the azulene unit in the framework is supported by high initial isosteric heat of adsorption of 6.8 kJ mol-1 for MOF-650. A detailed computational analysis using density functional theory was carried out in order to investigate the structure and electronic properties of MOF-650 and subsequently to understand its site-specific interactions with hydrogen.
- Barman, Samir,Khutia, Anupam,Koitz, Ralph,Blacque, Olivier,Furukawa, Hiroyasu,Iannuzzi, Marcella,Yaghi, Omar M.,Janiak, Christoph,Hutter, Jürg,Berke, Heinz
-
supporting information
p. 18823 - 18830
(2014/12/11)
-
- XANTHINE DERIVATIVES AS ADENOSINE A1 RECEPTOR ANTAGONISTS
-
A method of attenuating a cognitive deficit in a patient in need thereof comprising administering to the patient a xanthine derivative.
- -
-
-
- Selective adenosine receptor agents
-
Xanthine derivative which act selectively at adenosine receptors and which act in general as adenosine antagonists are disclosed. From in vitro studies it is known that specific physiological effects can be distinguished as a result of this selectively and that adenosine receptor activity in vitro correlates with adenosine receptor activity in vivo.Pharmaceutical preparations of the subject compounds can be prepared on the basis of the selective binding activity of the compounds disclosed herein which will enhance certain physiological effects while minimizing others, such as decreasing blood pressure without decreasing heart rate.
- -
-
-
- Synthesis and biological activity of novel carbacyclins having bicyclic substituents on the ω-chain
-
A number of carbacyclins having bicyclic substituents on the ω-chain have been synthesized and tested for antiplatelet aggregation activity in vitro (against collagen-induced aggregation of rat platelet), for reduction of systemic blood pressure in vivo (ability to reduce the blood pressure in anesthetized rat by iv injection), and for cytoprotective activity (protection against ethanol-induced rat gastric lesion). The most effective compound for each activity was [3aS-[2E,3aα,4α(3R),5β,6aα]]-5-[hexahydro-5-hydroxy-4-[3-hydroxy-3-(2- indanyl)-1-propynyl]-2(1H)-pentalenylidene]pentanoic acid (compound 11a), while some 1,4-benzodioxan analogues had selectivity for organ-protective activity, and indan analogues showed selectivity in their antiaggregation activity.
- Tomiyama,Wakabayashi,Yokota
-
p. 1988 - 1996
(2007/10/02)
-