Asymmetric Hydrogenation. Dimerization of Solvate Complexes: Synthesis and Characterization of Dimeric [Rh(DIPAMP)]22+, a Valuable Catalyst Precursor

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• 作者：Angelika Preetz ; Wolfgang Baumann ; Christian Fischer ; Hans-Joachim Drexler ; Thomas Schmidt ; Richard Thede ; Detlef Heller
• 刊名：Organometallics
• 出版年：2009
• 出版时间：July 13, 2009
• 年：2009
• 卷：28
• 期：13
• 页码：3673-3677
• 全文大小：781K
• 年卷期：v.28,no.13(July 13, 2009)
• ISSN：1520-6041

文摘

The hydrogenation of [Rh(DIPAMP)(NBD)]BF₄ (DIPAMP = 1,2-bis[(2-methoxyphenyl)(phenylphosphino)]ethane, NBD = 2,5-norbornadiene) in methanol leads not only to the formation of the expected solvate complex [Rh(DIPAMP)(MeOH)₂]BF₄ but also to the arene-bridged dimeric species [Rh(DIPAMP)]₂(BF₄)₂. The dimer is characterized by X-ray analysis as well as by an extensive NMR solution study including ¹H, ³¹P, and ¹⁰³Rh NMR. When used as a precursor for the asymmetric hydrogenation of prochiral olefins, [Rh(DIPAMP)]₂(BF₄)₂ operates without induction periods. It can be used for the formation of catalyst−substrate complexes such as [Rh(DIPAMP)(MAC)]BF₄ (MAC = methyl (Z)-α-acetamidocinnamate).