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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| Main Authors: | , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
June 24, 2013
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| In: |
Organometallics
Year: 2013, Volume: 32, Issue: 13, Pages: 3697-3709 |
| ISSN: | 1520-6041 |
| DOI: | 10.1021/om400323p |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1021/om400323p
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| Author Notes: | Peter D. Schweizer, Hubert Wadepohl, and Lutz H. Gade |
| Summary: | 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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| Item Description: | Gesehen am 09.08.2021 |
| Physical Description: | Online Resource |
| ISSN: | 1520-6041 |
| DOI: | 10.1021/om400323p |