Titanium-catalyzed hydrohydrazination of carbodiimides

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...

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Hauptverfasser: Schweizer, Peter Dominik (VerfasserIn) , Wadepohl, Hubert (VerfasserIn) , Gade, Lutz H. (VerfasserIn)
Dokumenttyp: Article (Journal)
Sprache:Englisch
Veröffentlicht: June 24, 2013
In: Organometallics
Year: 2013, Jahrgang: 32, Heft: 13, Pages: 3697-3709
ISSN:1520-6041
DOI:10.1021/om400323p
Online-Zugang:Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1021/om400323p
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Verfasserangaben:Peter D. Schweizer, Hubert Wadepohl, and Lutz H. Gade
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Zusammenfassung: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.
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Beschreibung:Online Resource
ISSN:1520-6041
DOI:10.1021/om400323p