Microwave-assisted synthesis of cyclopentadienone iron tricarbonyl complexes: molecular structures of [{η4-C4R2C(O)C4H8}Fe(CO)3] (R = Ph, 2,4-F2C6H3, 4-MeOC6H4) and attempts to prepare Fe(II) hydroxycyclopentadienyl–hydride complexes

Autor: Christian J. Richard, Graeme Hogarth, Derek Macmillan
Rok vydání: 2018
Předmět:
Zdroj: Transition Metal Chemistry. 43:421-430
ISSN: 1572-901X
0340-4285
DOI: 10.1007/s11243-018-0229-1
Popis: Microwave irradiation of 1,6-diynes, RC≡C(CH2)4C≡CR, with Fe(CO)5 in dimethylether leads to the facile and clean formation of cyclopentadienone complexes [{η4-C4R2C(O)C4H8}Fe(CO)3] in good yields resulting from a [2 + 2 + 1] cycloaddition. The molecular structures of three examples (R = Ph, 2,4-F2C6H3, 4-MeOC6H4) have been obtained. The addition of HBF4 leads to the clean and reversible formation of cationic hydroxycyclopentadienyl complexes [{η5-C4R2C(OH)C4H8}Fe(CO)3][BF4]. Sequential addition of hydroxide and acid has also been carried out in an attempt to prepare hydroxycyclopentadienyl–hydride complexes. These were largely unsuccessful but in one case a Shvo-type complex with a bridging hydride was detected by 1H NMR spectroscopy. Reasons for the differing behaviour of [{η4-C4(SiMe3)2C(O)C4H8}Fe(CO)3] and the related aryl-functionalised derivatives are considered. Microwave irradiation of 1,6-diynes, RC≡C(CH2)4C≡CR, with Fe(CO)5 gives cyclopentadienone complexes [{η4-C4R2C(O)C4H8}Fe(CO)3], the molecular structures of three (R = Ph, 2,4-F2C6H3, 4-MeOC6H4) being carried out. Sequential addition of hydroxide and acid was carried out in an attempt to prepare hydroxycyclopentadienyl–hydride complexes, and while largely unsuccessful, in one case a Shvo-type complex with a bridging hydride was suggested by 1H NMR spectroscopy.
Databáze: OpenAIRE
Externí odkaz: