Titanium-catalyzed hydrohydrazination of carbodiimides

• Verfasst von: Schweizer, Peter Dominik [VerfasserIn]
• Verfasst von: Wadepohl, Hubert [VerfasserIn]
• Verfasst von: Gade, Lutz H. [VerfasserIn]
• Titel: Titanium-catalyzed hydrohydrazination of carbodiimides
• Verf.angabe: Peter D. Schweizer, Hubert Wadepohl, and Lutz H. Gade
• E-Jahr: 2013
• Jahr: June 24, 2013
• Umfang: 13 S.
• Teil: volume:32
• Teil: year:2013
• Teil: number:13
• Teil: pages:3697-3709
• Teil: extent:13
• Fussnoten: Gesehen am 09.08.2021
• Titel Quelle: Enthalten in: Organometallics
• Ort Quelle: Washington, DC : ACS Publ., 1982
• Jahr Quelle: 2013
• Band/Heft Quelle: 32(2013), 13, Seite 3697-3709
• ISSN Quelle: 1520-6041
• DOI: doi:10.1021/om400323p
• Datenträger: Online-Ressource
• Sprache: eng
• K10plus-PPN: 1765944716

Abstract

Hydrazinediido complexes of the type [Cp*Ti(NxylN)(NNR2)(L)] (R = Ph, Me; Ar, fluorene, L = tBuNH2, Py; 3a–e) have been synthesized and used as catalysts for the hydrohydrazination of a series of carbodiimides, yielding aminoguanidines or fluoreneiminoguanidines. The highest yields were obtained for diarylhydrazines and fluorenone hydrazone at temperatures between 80 and 105 °C. Stoichiometric reactions of hydrazinediido complexes with iPrNCNiPr led to an equilibrium with the resulting [2 + 2] cycloadducts 4a–f, which were characterized by 1H, 13C, and 15N NMR spectroscopy as well as X-ray diffraction. The proposed mechanism, which is closely related to that previously established for the hydrohydrazination of alkynes and allenes, was found to be consistent with the results of a kinetic study. The dynamic structures of aminoguanidines and fluoreneiminoguanidines were characterized by NMR spectroscopy, and the minimum configurations were found to be stabilized by intramolecular hydrogen bonding.