New Racemic Planar-Chiral Metalloligands Derived from Donor-Substituted Indenes: A Synthetic, Structural, and Catalytic Investigation

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• 作者：Dominik Wechsler ; Matthew A. Rankin ; Robert McDonald ; Michael J. Ferguson ; Gabriele Schatte ; Mark Stradiotto
• 刊名：Organometallics
• 出版年：2007
• 出版时间：December 3, 2007
• 年：2007
• 卷：26
• 期：25
• 页码：6418 - 6427
• 全文大小：216K
• 年卷期：v.26,no.25(December 3, 2007)
• ISSN：1520-6041

文摘

The synthesis and characterization of a new family of (⁵-indenyl)ML_n complexes (ML_n = Mn(CO)₃,Cp*Ru, or Cp*Fe; Cp* = ⁵-C₅Me₅) derived from 3-PⁱPr₂-indene, 1-PⁱPr₂-2-NMe₂-indene (1a[H]), or1-P(S)ⁱPr₂-2-NMe₂-indene (1b[H]) are described. Lithiation of 1b[H] followed by treatment with BrMn(CO)₅, 0.25 equiv of [Cp*RuCl]₄, or Cp*Li/FeCl₂ provided the corresponding (⁵-1b)ML_n complexes(ML_n = Mn(CO)₃, 2a, 96%; Cp*Ru, 2b, 87%; or Cp*Fe, 2c, 55%). Similarly, treatment of 1a[Li] with0.25 equiv of [Cp*RuCl]₄ or Cp*Li/FeCl₂ provided the corresponding (⁵-1a)ML_n complexes (ML_n =Cp*Ru, 3b, 74%; or Cp*Fe, 3c, 62%). Whereas combination of 3b and 0.5 equiv of [(COD)RhCl]₂afforded [(COD)Rh(²-P,N-3b)]⁺Cl^- ([4b]⁺Cl^-; 49% isolated yield), under similar conditions 3c wasobserved to undergo a decomposition reaction resulting in the formation of the zwitterionic complex(COD)Rh(²-P,N-1a) (5; COD = ⁴-1,5-cyclooctadiene). Each of 3a-c was observed to react cleanlywith [(COD)Rh(THF)₂]⁺BF₄^- (prepared in situ) to give the corresponding [(COD)Rh(²-P,N-3a-c)]⁺BF₄^-complex ([4a-c]⁺BF₄^-; 87%, 96%, and 89% isolated yield, respectively). Whereas lithiation of 3-PⁱPr₂-indene followed by the addition of BrMn(CO)₅ generated a complex mixture of products, similarreactions employing 0.25 equiv of [Cp*RuCl]₄ or Cp*Li/FeCl₂ afforded 6b or 6c in 98% and 43% yield,respectively. Treatment of 6b with 0.5 equiv of [(COD)RhCl]₂ allowed for the isolation of (COD)RhCl(¹-P-6b) 7 in 96% isolated yield. Each of [4a-c]⁺BF₄^- proved to be an active catalyst for addition ofpinacolborane to styrene, with the observed regioselectivity being dependent on the nature of the ⁵-coordinated metal fragment, as well as the solvent employed. Single-crystal X-ray diffraction data for2a, 2b, 2c, 3b, [4c]⁺BF₄^-, and 7 are provided.