Photoinduced Reactions of Diruthenium Tetrahydride Complexes: Carbon–Hydrogen Bond Cleavage of Tetrahydrofuran Leading to Bridging Cyclic Fischer-Type Carbene Complexes

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• 作者：Ryuichi Shimogawa ; Gen-ichi Konishi ; Toshiro Takao ; Hiroharu Suzuki
• 刊名：Organometallics
• 出版年：2016
• 出版时间：May 23, 2016
• 年：2016
• 卷：35
• 期：10
• 页码：1446-1457
• 全文大小：655K
• 年卷期：0
• ISSN：1520-6041

文摘

Photochemical reactions of diruthenium tetrahydride complexes containing cyclopentadienyls as auxiliary ligands, CpsRu(μ-H)₄RuCps (1) (a: Cps = C₅Me₅ (Cp*), b: C₅EtMe₄ (Cp^Et), and c: 1,2,4-C₅(t-Bu)₃H₂ (Cp^‡)), with tetrahydrofuran were studied for elucidation of the reaction mode of dinuclear complexes containing multiple bridging hydrides. Complexes 1a–c reacted with tetrahydrofuran under UV irradiation (365 nm) to produce bridging cyclic Fischer-type carbene complexes, {CpsRu(μ-H)}₂(μ-cyclo-CCH₂CH₂CH₂O−)(μ-H)₂ (5), via consecutive C–H bond cleavage at the α-position of the oxygen atom. The characteristic cyclic structures of the bridging carbene ligands were unambiguously confirmed by X-ray diffraction studies. Line-shape analysis of the variable-temperature ¹H NMR spectra of 5c demonstrated the rotation of the bridging carbene ligand.