Transannular reactions of two parallel 1,3-butadiynes

• Verfasst von: Schmidt, Erik M. [VerfasserIn]
• Verfasst von: Gleiter, Rolf [VerfasserIn]
• Verfasst von: Rominger, Frank [VerfasserIn]
• Titel: Transannular reactions of two parallel 1,3-butadiynes
• Titelzusatz: syntheses, structures, and reactions of 1-azacyclotetradeca-3,5,10,12-tetrayne derivatives
• Verf.angabe: Erik M. Schmidt, Rolf Gleiter, and Frank Rominger
• E-Jahr: 2003
• Jahr: 08 April 2003
• Umfang: 9 S.
• Fussnoten: Gesehen am 21.10.2020
• Titel Quelle: Enthalten in: Chemistry - a European journal
• Ort Quelle: Weinheim : Wiley-VCH, 1995
• Jahr Quelle: 2003
• Band/Heft Quelle: 9(2003), 8, Seite 1814-1822
• ISSN Quelle: 1521-3765
• DOI: doi:10.1002/chem.200390208
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: butadiynes
• Sach-SW: medium-ring compounds
• Sach-SW: structure elucidation
• Sach-SW: transannular reactions
• K10plus-PPN: 1736137433

Abstract

The synthesis of 1alkyl and 1aryl-1-azacyclotetradeca-3,5,10,12-tetraynes was achieved in a stepwise approach. The key intermediate was 1,13-dibromotrideca-2,4,9,11-tetrayne (18). Reaction with methyl- (19 a), ethyl- (19 b), isopropyl- (19 c), n-butyl- (19 d), and tert-butylamine (19 e) as well as aniline (19 f) and p-methoxyaniline (19 g) gave the corresponding 14-membered tetraynes 20 a-20 g. The ring inversion process of 20 b was studied by variable temperature 1H NMR spectroscopy. From these measurements a value of 10.6 kcal mol−1 was calculated for ΔG≠. Xray investigations on single crystals of 20 b, 20 c, and 20 f revealed the axial position for the substituent at each nitrogen atom. For 20 b we encountered the chair conformation, for 20 c both chair and boat conformations, and for 20 f the boat conformation in the solid state. The reaction of 20 c with concentrated HCl in ethanol yielded 2,10-dichloro-6-isopropyl-6-azatricyclo[9.3.0.04,8]tetradeca-1(11),2,4(8),9-tetraene (25 c). Compound 25 c was oxidized by 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) to 27 c. The structure of the latter was confirmed by Xray investigations. The reaction of 20 c in aqueous HCl lead to the formation of 10-chloro-2-isopropyl-1,3,4,6,7,8-hexahydro-2H-benzo[g]isoquinolin-9-one (37 c). The structure of 37 c was verified by Xray studies on single crystals.