Conformational polymorphism in a chiral spiro-cis-ansa-bridged cyclotriphosphazene derivative
نویسندگان
چکیده
منابع مشابه
ansa-Metallocene derivatives XXI *. Syntheses of etheno-bridged ansa-titanocene derivatives by the McMurry reaction
207 Novel olefin-linked biscylopentadienylligands have been prepared by McMurry coupling reactions of benzoyland acetyl-cyclopentadienyl sodium. Reactions of the disodium salts with TiC1 4 or TiCl 3 • 3THF afford the alkene-bridged ansa-titanocene dichlorides. 13C-NMR shifts of the bridge carbon atoms do not indicate any interaction between the olefin 'IT-system and the metal.
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The biphenyl-bridged. chiral zirconocene complex rac-2.2' -biphenyl-bis( 3.4-dimethylcyclopentadienyl I zirconium dichloride catalyzes the reaction of 1.6and 1,7 -dienes with excess dibutyl magnesium to bis( butyl-magnesio-methyl '-substituted cycloalkanederivatives. Analogous reactions occur with butyl magnesium chloride and with heteroatom-t.:Ontaining dienes. The preference of 1.6-dienes for...
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An efficient one-pot three-component procedure for the synthesis of new chiral spiro-oxindolopyrrolizidines with highly regio-, diastereo-, and enantioselective from 1,3-dipolar cycloaddition of azomethine ylides and optically pure active cinamoyl oxazolidinone are described. The process occurs at room temperature in aqueous ethanol as green solvent and in the absence of any bidentate chelating...
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Although crystal polymorphism of carbamazepine (CBZ), an anticonvulsant used to treat epilepsy, has been known for decades, the phenomenon has only recently been noted for its keto-derivative oxcarbazepine (OCB). Here it is demonstrated that OCB possesses at least three anhydrous polymorphs. Although all forms are morphologically similar, making differentiation between crystal modifications by ...
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An efficient one-pot three-component procedure for the synthesis of new chiral spiro-oxindolopyrrolizidines with highly regio-, diastereo-, and enantioselective from 1,3-dipolar cycloaddition of azomethine ylides and optically pure active cinamoyl oxazolidinone are described. The process occurs at room temperature in aqueous ethanol as green solvent and in the absence of any bidentate chelating...
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ژورنال
عنوان ژورنال: Acta Crystallographica Section C Crystal Structure Communications
سال: 2001
ISSN: 0108-2701
DOI: 10.1107/s010827010101770x