Reactions of the 蟽,蟺-furyl complex [Fe₂(CO)₆(渭-Fu)(渭-PFu₂)] (Fu聽=聽C₄H₃O) with phosphines: Carbonyl substitution, migratory carbonyl insertion and cyclometallation-induced furan elimination

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• 作者：Ahibur Rahaman ; Fakir Rafiqul Alam ; Shishir Ghosh ; Derek A. Tocher ; Matti Haukka ; Shariff E. Kabir ; Ebbe Nordl ; er ; Graeme Hogarth
• 关键词：Diiron ; Furyl ; Migratory insertion ; Cyclometallation ; Carbon&ndash ; phosphorus bond formation
• 刊名：Journal of Organometallic Chemistry
• 出版年：1 February, 2014
• 年：2014
• 卷：751
• 期：Complete
• 页码：326-335
• 全文大小：982 K

文摘

The reactivity of the 蟽,蟺-furyl complex [Fe₂(CO)₆(渭-Fu)(渭-PFu₂)] (1) towards PPh₃ and a range of bidentate phosphines has been studied and a number of different reaction products have been identified. With PPh₃,聽carbonyl substitution affords [Fe₂(CO)₅(PPh₃)(渭-Fu)(渭-PFu₂)] (2) in which the new phosphine is coordinated to the iron center that is 蟽-coordinated by the bridging furyl moiety. With small bite-angle diphosphines - bis(diphenylphosphino)methane (dppm) and 1,8-bis(diphenylphosphino)naphthalene (dppn) - carbonyl substitution and migratory carbonyl insertion result to give the furyl-acyl complexes with bridging, [Fe₂(CO)₄(渭-dppm)(渭-OCFu)(渭-PFu₂)] (3), or chelating, [Fe₂(CO)₄(魏²-dppn)(渭-OC-Fu)(渭-PFu₂)] (4), diphosphines, respectively. With the more flexible diphosphines Ph₂P(CH₂)_nPPh₂ (n聽=聽2, dppe, n聽=聽3, dppp), the cyclometallated products [Fe₂(CO)₅{渭,魏²-C₆H₄PPh(CH₂)_nPPh₂}(渭-PFu₂)] (n聽=聽2, 5; n聽=聽3, 6) are isolated as a result of carbonyl substitution and furan elimination, and a similar complex [Fe₂(CO)₅{渭,魏²-C₆H₄PPh(C₆H₄)PPh₂}(渭-PFu₂)] (7) is generated from the more rigid diphosphine bis(diphenylphosphino)benzene (dppb). With bis(diphenylphosphino)-1,1-binaphthalene (1,1-BINAP) the novel tridentate phosphine complex [Fe₂(CO)₅{渭,魏³-C₆H₄P(C₂₀H₁₂PPh₂)C₆H₄PFu}] (8) results from the putative coupling of cyclometallated diphosphine and difurylphosphido ligands, following elimination of two equivalents of furan. The crystal structures of 2, 3, 5 and 8 have been determined and allow a detailed insight into the overall reaction profile.