Optical Resolution of Binaphthyl and Biphenanthryl Diols by Inclusion Crystallization with N-Alkylcinchonidium Halides. Structural Characterization of the Resolved Materials

Toda, Fumio; Tanaka, Kōichi; Stein, Zafra; Goldberg, Israel

doi:10.1021/jo00098a038

Cited by 90 publications

(24 citation statements)

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“…The absolute configuration of 3,3 0 -dihydroxy-4,4 0 -biphenanthryl was originally assigned 13 as (2)-(aS), but was later determined 15 to be (2)-(aR). The absolute configurations of 10,10 0 -dihydroxy-9,9 0 -biphenanthryl and 2,2 0 -dihydroxy-1,1 0 -biphenanthryl were determined 16,17 to be (1)-(aR). The absolute configurations of 10,10 0 -dimethoxy-9,9 0 -biphenanthryl and 2,2 0 -dimethoxy-1,1 0 -biphenanthryl have also been reported 16,17 in the literature.…”

Section: Introductionmentioning

confidence: 99%

“…The absolute configurations of 10,10 0 -dihydroxy-9,9 0 -biphenanthryl and 2,2 0 -dihydroxy-1,1 0 -biphenanthryl were determined 16,17 to be (1)-(aR). The absolute configurations of 10,10 0 -dimethoxy-9,9 0 -biphenanthryl and 2,2 0 -dimethoxy-1,1 0 -biphenanthryl have also been reported 16,17 in the literature. However, modern chiroptical spectroscopic methods have not yet been applied to any of these molecules.…”

Section: Introductionmentioning

confidence: 99%

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Determination of the absolute stereochemistry of chiral biphenanthryls in solution phase using chiroptical spectroscopic methods: 2,2′‐Diphenyl‐[3,3′‐biphenanthrene]‐4,4′‐diol

2007

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Although the exciton coupling model has been widely used in the literature to suggest the absolute configuration using electronic circular dichroism (ECD) spectra, chiral biphenanthryl systems are one group of molecules where the application of the exciton model yields ambiguous conclusions. The use of 2,2'-diphenyl-[3,3'-biphenanthrene]-4,4'-diol, known as VAPOL, as a chiral ligand for enantioselective catalysis necessitates the reliable determination of its absolute configuration. Based on the X-ray diffraction data of its phosphoric amide derivative, the configuration of VAPOL has been determined in the literature to be (+)-(aS). The experimental vibrational circular dichroism, ECD and optical rotatory dispersion spectra, and corresponding quantum mechanical predictions of VAPOL are used in this manuscript to independently determine its absolute configuration.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Determination of the absolute stereochemistry of chiral biphenanthryls in solution phase using chiroptical spectroscopic methods: 2,2′‐Diphenyl‐[3,3′‐biphenanthrene]‐4,4′‐diol

2007

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“…All the chemicals used were purchased from either the Aldrich Chemical Company or ACROS Organics. Optically pure binaphthol was resolved according to literature procedures [38]. Optical rotation was measured on a Rudolph Autopol III polarimeter and a JASCO-J-720 circular dichroism spectroscopy.…”

Section: Methodsmentioning

confidence: 99%

Synthesis of a series of soluble main-chain chiral nonracemic poly(alkyl-aryl ketone)

Wei¹,

Wang²,

Wu³

et al. 2008

Express Polym. Lett.

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Abstract.A series of main-chain chiral polyketones have been synthesized through condensation polymerization of a dihalide and a diketone with optically pure binaphthyl moiety as linkage in the polymer backbone. The solubility of the polymers can be easily enhanced by substituents at the alpha position next to the carbonyl groups. Reducing the steric hindrance of the substituents in the monomers increases the reactivity of the polymerization. The chiral polymers exhibit large optical rotations. Circular Dichroism (CD) spectra of the polymers are similar to those of the corresponding monomers. The novel synthetic strategy may have great impact on future development of palladium catalyzed condensation polymerizations. The highly soluble chiral polymers synthesized allow for preparation of materials in the form of thin films and have potentials applications in various areas such as chiral separation and recognition.

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“…51,80,84,85) Oxidative coupling of 9-phenanthrol (4o) using catalyst (R a ,S,S)-2 was investigated; the results are summarized in Table 4. Among the reaction solvents studied, CH 2 Cl 2 provided the highest reaction rate with high enantioselectivity, giving biphenanthrol 5o in 94% yield with 88% ee (entry 4).…”

Section: Dinuclear Vanadium Complexes Catalyzed Oxidative Coupling Rementioning

confidence: 99%

Development of Dinuclear Vanadium Catalysts for Enantioselective Coupling of 2-Naphthols via a Dual Activation Mechanism

Takizawa

2009

CHEMICAL & PHARMACEUTICAL BULLETIN

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Catalytic asymmetric reactions are among the most powerful synthetic methods to obtain optically active compounds.1,2) Recent challenges focus on the development of asymmetric catalysts for carbon-carbon bond-forming reactions with high activity and broad substrate generality, which lead to practical, efficient, and environmentally benign chemical syntheses. Dual activation systems for substrates such as nucleophiles and electrophiles lead to enhanced reaction rates and more specific control of the transition structure with respect to the catalyst's asymmetric environment. Dual activation catalyses can be classified into three categories ( Fig. 1): Type 1) dual activation using two different kinds of catalysts [3][4][5][6][7][8][9][10][11][12] ; Type 2) conjugated-type dual activation with a functional group such as a phosphate which has both acidic and basic sites in one functionality [13][14][15] ; and Type 3) dual activation by two catalytic sites in a single catalyst. For efficient dual activation of the substrates, a balance between these two functionalities in the catalyst is required. For example, in an acid-base type catalyst the selfquenching reaction of acidic and basic moieties on the catalyst can lead to its inactivation.We postulated that a chiral complex possessing two identical metal centers in a single molecule, which could activate two substrates simultaneously in a homolytic coupling reaction of 2-naphthol molecules, would enhance the reaction rate with high enantioselectivity. To achieve the new dual activation catalysis in an oxidative coupling reaction, we designed the catalyst (R a ,S,S)-1 42) bearing two active sites attached to a binaphthyl skeleton, taking advantage of the activation entropy (Fig. 2). Activation entropy strongly con- Development of Dinuclear Vanadium Catalysts for Enantioselective Coupling of 2-Naphthols via a Dual Activation MechanismShinobu TAKIZAWA This review describes our recent efforts in the development of chiral dinuclear vanadium complexes which work as dual activation catalysts for oxidative coupling of 2-naphthols. A chiral dinuclear vanadium(IV) complex (R a ,S,S)-1a possessing (S)-tert-leucine moieties at the 3,3 -positions of the (R)-binaphthyl skeleton was developed, and found to promote oxidative coupling of 2-naphthol to afford (S)-1,1 -bi-2-naphthol (BINOL) with 91% ee. To verify the dual activation mechanism, mononuclear vanadium(IV) complex (S)-10 was also prepared. Kinetic analysis revealed that the reaction rate of oxidative coupling of 2-naphthol promoted by (R a ,S,S)-1a is 48.3 times faster than that of (S)-10. In the coupling reaction, the two vanadium metals in the chiral complex activate two molecules of 2-naphthol simultaneously achieving a high reaction rate with high enantiocontrol. Since the dinuclear vanadium(IV) complex was found to be readily oxidized to afford a corresponding vanadium(V) species during preparation in air, a new synthetic procedure using VOCl 3 and a convenient one-pot procedure using VOSO 4 under O 2 have been applie...

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Optical Resolution of Binaphthyl and Biphenanthryl Diols by Inclusion Crystallization with N-Alkylcinchonidium Halides. Structural Characterization of the Resolved Materials

Cited by 90 publications

References 1 publication

Determination of the absolute stereochemistry of chiral biphenanthryls in solution phase using chiroptical spectroscopic methods: 2,2′‐Diphenyl‐[3,3′‐biphenanthrene]‐4,4′‐diol

Determination of the absolute stereochemistry of chiral biphenanthryls in solution phase using chiroptical spectroscopic methods: 2,2′‐Diphenyl‐[3,3′‐biphenanthrene]‐4,4′‐diol

Synthesis of a series of soluble main-chain chiral nonracemic poly(alkyl-aryl ketone)

Development of Dinuclear Vanadium Catalysts for Enantioselective Coupling of 2-Naphthols via a Dual Activation Mechanism

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