A Homodinuclear Mn(III)<sub>2</sub>−Schiff Base Complex for Catalytic Asymmetric 1,4-Additions of Oxindoles to Nitroalkenes

Kato, Yuko; Furutachi, Makoto; Chen, Zhihua; Mitsunuma, Harunobu; Matsunaga, Shigeki; Shibasaki, Masakatsu

doi:10.1021/ja903566u

Cited by 214 publications

(61 citation statements)

References 32 publications

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“…[8][9][10] There have been many reports on activity of Schiff base complexes in homogeneous and heterogeneous catalysis. [11][12][13][14] The first-row late transition metals such as iron, cobalt, nickel and copper are now the most important transition metals used as catalysts in the * For correspondence development of organic reactions, 15 rather than the catalytically active noble metals such as ruthenium, rhodium and palladium. 16 The carbon-carbon bond forming reaction is one of the simple and versatile method in organic synthesis.…”

Section: Introductionmentioning

confidence: 99%

Nickel(II) complexes containing ONS donor ligands: Synthesis, characterization, crystal structure and catalytic application towards C-C cross-coupling reactions

et al. 2015

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Nickel(II) complexes containing thiosemicarbazone ligands [Ni(L) 2 ] (1-3) (L = 9,10-phenanthrenequinonethiosemicarbazone (HL 1 ), 9,10-phenanthrenequinone-N-methylthio semicarbazone (HL 2 ) and 9, 10-phenanthrenequinone-N-phenylthiosemicarbazone (HL 3 )) have been synthesized and characterized by elemental analysis and spectroscopic (IR, UV-Vis, 1 H, 13 C-NMR and ESI mass) methods. The molecular structures of complexes 1 and 2 were identified by means of single-crystal X-ray diffraction analysis. The analysis revealed that the complexes possess a distorted octahedral geometry with the ligand coordinating in a uni-negative tridentate ONS fashion. The catalytic activity of complexes towards some C-C coupling reactions (viz., KumadaCorriu, Suzuki-Miyaura and Sonogashira) has been examined. The complexes behave as efficient catalysts in the Kumada-Corriu and Sonogashira coupling reactions rather than Suzuki-Miyaura coupling.

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Section: Introductionmentioning

confidence: 99%

Nickel(II) complexes containing ONS donor ligands: Synthesis, characterization, crystal structure and catalytic application towards C-C cross-coupling reactions

et al. 2015

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“…28 On the other hand, the Mn 2 1b catalyst was the best for asymmetric 1,4 addition of N Boc oxindoles to nitroalkenes for chiral β amino oxindole synthesis. 29 In all the cases shown in Figure 8, the homodinuclear Ni 2 , Co 2 , or Mn 2 Schiff base complexes displayed much superior reactivity and stereoselectivity to mono nuclear Ni , Co , or Mn salen complexes. The Ni 2 1b catalyst was also applicable to the catalytic asymmetric amination of 3 substituted N Boc oxindoles, for which 1 mol% of Ni 2 1b gave products in 86 99% yield and 87 99% ee (Table 5).…”

Section: Homobimetallic Transition Metal/schiff Base Complex As a Lewmentioning

confidence: 93%

Bifunctional Asymmetric Catalysis Based on Dinuclear Schiff Base Complexes

Shibasaki

Matsunaga

2010

J. Synth. Org. Chem. Jpn.

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Catalytic asymmetric processes are potentially more economical and environmentally benign than those using stoichiometric amounts of chiral reagents. 1 The development of asymmetric catalysts that exhibit high activity, high stereoselectivity, and broad substrate generality is highly desirable, and is a major theme of modern organic synthesis. In approaches to this issue, the concept of bifunctional asymmetric catalysis, wherein both partners of a bimolecular reaction are simultaneously activated (dual activation, Figure 1), is often utilized for the design of metallic catalysts as well as organocatalysts. 2Since our fi rst report on a lanthanum/lithium/binolate heterobimetallic complex in the early 1990 s, 3 our group has been working intensively on heterobimetallic Lewis acid/Brønsted base bifunctional catalysis by rare earth metal/alkali metal complexes using BINOL, Pybox, and their derivatives as ligands. 4 When designing bimetallic asymmetric catalysts, the construction of a suitable chiral environment for each targeted reaction is important for achieving the effective dual activation of nucleophiles and electrophiles through the cooperation of two metal centers. Optimization of enantioselectivity and reactivity requires a strategy for constructing a fl exible and diverse chiral environment. 5 In order to broaden the scope of bimetallic bifunctional asymmetric catalysis, the development of a heterobimetallic system not using BINOLs or alkali metals is desirable. We believe that new metal combinations will lead to novel catalytic activity and selectivity.Chiral Schiff base ligands, such as salens, are one class of privileged ligands in asymmetric catalysis. Over the last two decades, various transition metal salen and group 13 metal salen complexes have been widely utilized for a broad range of catalytic enantioselective transformations. 6 In the fi eld of bifunctional catalysis, Jacobsen and coworkers have developed an elegant intramolecular cooperative catalysis using two metal salen complexes.6a Attemps to further strengthen the catalytic activity by linking two salen complexes have also been reported. 7 In addition, several groups have nicely expanded the potential of Schiff base ligands by using them for heterobimetallic transition metal/alkali metal catalysts and transition metal/group 13 metal catalysts.8 However, the combination of transition metal and rare earth metal in chiral heterobimetallic Schiff base catalysts had not been investigated at the time we started our project. In this account, our own efforts toward the design and development of bifunctional heterodinuclear and homodinuclear Schiff base catalysts since 2007 are described. For reports from other groups, see a recent review article 7 and leading references. Heterobimetallic Cu/Sm/Schiff base Complex as a Lewis acid/Brønsted base Bifunctional CatalystWhen developing heterobimetallic complexes, the design of a suitable multidentate ligand is important for controlling the position of the two different metals in the complex. These posit...

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“…With Ga(O-iPr) 3 and other rare earth metal triflates, the reactivity decreased in correlation with the Lewis acidity of the rare earth metals (Yb > Gd > Nd > La) [17], while good to excellent enantioselectivity [19]. In a similar manner, homodinuclear Co 2 -1b [19,20] and Mn 2 -1b [21] complexes were also synthesized in good yield (Scheme 3). The homodinuclear Ni 2 -Schiff base 1b complex was stable and storable under air at room temperature for more than 3 months without any loss of activity.…”

Section: Lewis Acid/lewis Acid Heterobimetallic Schiff Base Catalystmentioning

confidence: 98%

Multimetallic Multifunctional Catalysts for Asymmetric Reactions

Shibasaki

Kanai

Matsunaga

et al. 2011

Bifunctional Molecular Catalysis

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The utility of several types of multimetallic asymmetric catalysts is reviewed. The appropriate design of multidentate chiral ligands provides homobimetallic, heterobimetallic, and polymetallic catalysts upon complexation with metal cations. Cooperative work of multiple catalytically active sites in the asymmetric multimetallic catalysts allows for enhanced catalytic activity and stereoselectivity over monometallic catalysts. Facile systematic tuning of the asymmetric multimetallic catalysts by manipulation of multidentate ligand structure and combination of metal cations enables the generation of diverse set of catalysts having distinct three-dimensional and catalytic properties, boosting the optimization process to identify the best catalyst for a specific reaction of interest.

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A Homodinuclear Mn(III)₂−Schiff Base Complex for Catalytic Asymmetric 1,4-Additions of Oxindoles to Nitroalkenes

Cited by 214 publications

References 32 publications

Nickel(II) complexes containing ONS donor ligands: Synthesis, characterization, crystal structure and catalytic application towards C-C cross-coupling reactions

Nickel(II) complexes containing ONS donor ligands: Synthesis, characterization, crystal structure and catalytic application towards C-C cross-coupling reactions

Bifunctional Asymmetric Catalysis Based on Dinuclear Schiff Base Complexes

Multimetallic Multifunctional Catalysts for Asymmetric Reactions

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A Homodinuclear Mn(III)2−Schiff Base Complex for Catalytic Asymmetric 1,4-Additions of Oxindoles to Nitroalkenes

Cited by 214 publications

References 32 publications

Nickel(II) complexes containing ONS donor ligands: Synthesis, characterization, crystal structure and catalytic application towards C-C cross-coupling reactions

Nickel(II) complexes containing ONS donor ligands: Synthesis, characterization, crystal structure and catalytic application towards C-C cross-coupling reactions

Bifunctional Asymmetric Catalysis Based on Dinuclear Schiff Base Complexes

Multimetallic Multifunctional Catalysts for Asymmetric Reactions

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A Homodinuclear Mn(III)₂−Schiff Base Complex for Catalytic Asymmetric 1,4-Additions of Oxindoles to Nitroalkenes