Cyclic trimers and tetramers with piperazine and 2-butyne as building blocks

• Verfasst von: Gleiter, Rolf [VerfasserIn]
• Verfasst von: Hövermann, Kirstin [VerfasserIn]
• Verfasst von: Rominger, Frank [VerfasserIn]
• Verfasst von: Oeser, Thomas [VerfasserIn]
• Titel: Cyclic trimers and tetramers with piperazine and 2-butyne as building blocks
• Gefeierte Person: Neidlein, Richard [GefeierteR]
• Verf.angabe: Rolf Gleiter, Kirstin Hövermann, Frank Rominger, and Thomas Oeser
• E-Jahr: 2001
• Jahr: 22 January 2001
• Umfang: 4 S.
• Teil: year:2001
• Teil: number:4
• Teil: pages:725-728
• Teil: extent:4
• Fussnoten: Dedicated to Professor Richard Neidlein on the occasion of his 70th birthday ; Gesehen am 27.10.2020
• Titel Quelle: Enthalten in: European journal of organic chemistry
• Ort Quelle: Weinheim : Wiley-VCH Verl., 1998
• Jahr Quelle: 2001
• Band/Heft Quelle: (2001), 4, Seite 725-728
• ISSN Quelle: 1099-0690
• DOI: doi:10.1002/1099-0690(200102)2001:4<725::AID-EJOC725>3.0.CO;2-I
• Datenträger: Online-Ressource
• Dokumenttyp: Festschrift
• Sprache: eng
• Sach-SW: Alkynes
• Sach-SW: Inclusion compounds
• Sach-SW: Macrocycles
• Sach-SW: Nitrogen heterocycles
• K10plus-PPN: 173667322X

Abstract

The reaction of piperazine with 2-butyne-1,4-ditosylate in a 1:1 ratio yields the cyclic trimer 7 and the cyclic tetramer 8. 1H NMR investigations on 7 and 8 reveal a dynamic process with ΔG‡ = 13 kcal/mol. This process is attributed to an inversion of the piperazine rings. Single crystals of 7·CH3OH, 7·2 CF3COOH·H2O and 8 have been isolated and investigated by X-ray diffraction. In the first two cases methanol, or water and CF3CO2−, were included in the interior of the ring.