Ruthenium catalyzed asymmetric transfer hydrogenation based on chiral P,N,O Schiff base ligands and crystal structure of a ruthenium(II) complex bearing chiral P,N,O Schiff base ligands

Kwong, Hoi‐Lun; Lee, Wing Sze; Lai, Tat Shing; Wong, Wing Tak

doi:10.1016/s1387-7003(99)00012-x

Cited by 35 publications

(10 citation statements)

References 29 publications

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“…In 1997, an ether ligand was introduced as a hemilabile ligand in PNO-L1 and PNO-L2 by the Mathieu group. 126 Subsequently in 1999, Kwong 127 reported a Schiff base-based chiral PNO-L3. The formation of a cationic Ru-(PNO-L3) 2 complex was observed to have a metal/ligand ratio of 1:2.…”

Section: Pno-type Ligandsmentioning

confidence: 99%

“…168,169 In 1999, Kwong reported the synthesis of cationic complex PNO-Ru-4 by reacting PNO-L3 with [RuCl 2 (DMSO) 4 ] in a L/ M ratio of 2:1. 127 Clarke and workers modified the synthetic procedure by reacting PNN-L2 with [RuCl 2 (DMSO) 4 ] at 120 °C in a microwave oven and successfully prepared PNN-Ru-2a ∼ PNN-Ru-2f, 89,91 PNO-Ru-5, 94 and PNO-Ru-6 130 with a L/ M ratio of 1:1 (Scheme 2).…”

Section: Ruthenium and Osmiummentioning

confidence: 99%

“…In 1999, Kwong 127 developed chiral ligand PNO-L3; its ruthenium catalyst achieved 75% ee and 73% conversion in the ATH of acetophenone. PNO-Ru-3 was successfully synthesized but had shown slower reaction rate under the catalytic conditions.…”

Section: Enantioselective Hydrogenation Of Co Bondsmentioning

confidence: 99%

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Chiral Tridentate Ligands in Transition Metal-Catalyzed Asymmetric Hydrogenation

2021

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Asymmetric hydrogenation (AH) of double bonds has been one of the most effective methods for the preparation of chiral molecules and for the synthesis of important chiral building blocks. In the past 60 years, noble metals with bidentate ligands have shown marvelous reactivity and enantioselectivity in asymmetric hydrogenation of a series of prochiral substrates. In recent years, developing chiral tridentate ligands has played an increasingly important role in AH. With modular frameworks and a variety of functionalities on the side arms, chiral tridentate ligand complexes enable both reactivities and stereoselectivities. Although great achievements have been made for noble metal catalysts with chiral tridentate ligands since the 1990s, the design of chiral tridentate ligands for earth abundant metal catalysts has still been in high demand. This review summarizes the development of chiral tridentate ligands for homogeneous asymmetric hydrogenation. The philosophy of ligand design and the reaction mechanisms are highlighted and discussed as well.

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Section: Pno-type Ligandsmentioning

confidence: 99%

Section: Ruthenium and Osmiummentioning

confidence: 99%

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Chiral Tridentate Ligands in Transition Metal-Catalyzed Asymmetric Hydrogenation

2021

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“…Thus, diamines which are easily accessible in various forms were introduced as coligands. Diaminediphosphineruthenium(II) complexes with various combinations of phosphine and diamine ligands have been successfully developed − to catalyze the hydrogenation of ketones in the presence of carbon−carbon multiple bonds with high diastereo- and enantioselectivity. − …”

Section: Introductionmentioning

confidence: 99%

Structural Studies of an Array of Mixed Diamine Phosphine Ruthenium(II) Complexes¹

et al. 2001

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Treatment of RuCl2(η2-Ph2PCH2CH2OCH3)2 with various chelating diamines permitted the isolation of the corresponding RuCl2(η1-Ph2PCH2CH2OCH3)2(diamine) complexes in high yield (diamine = 1,2-diaminoethane, 1,2-diaminopropane, 1,3-diaminopropane, 1,2-phenylenediamine, 1,8-diaminonaphthalene, 2,2‘-bipyridine, 1,10-phenanthroline). In solution, all complexes prefer the trans-chloro cis-phosphine arrangement, as deduced by NMR spectroscopy. X-ray studies showed that in the solid state all three possible isomers of the octahedral RuCl2P2(diamine) complexes are present. The reaction of the RuCl2(η1-Ph2PCH2CH2OCH3)2(diamine) complexes with 1 equiv of AgSbF6, AgBF4, or TlPF6 leads to the abstraction of one chloride by simultaneously coordinating one ether oxygen to ruthenium and forming monocationic [RuCl(η1-Ph2PCH2CH2OCH3)(η2-Ph2PCH2CH2OCH3)(diamine)]+ compounds. If a large excess of silver or thallium salt is used, the dichloro complexes are converted to the [Ru(η2-Ph2PCH2CH2OCH3)2(diamine)]2+ dications. In the case of 1,2-phenylendiamine as coligand, the corresponding dication is only observed in traces. NMR spectroscopic investigations and X-ray structural analyses confirm the η1 and η2 coordination of the ether−phosphine ligands in the corresponding mono- and dicationic ruthenium(II) complexes.

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“…The νN-H and νC=O bands in the free amine and aldehyde compounds have totally disappeared in Schiff base ligands after the condensation. The displacement of C=N stretching frequencies from 1610-1636 cm -1 (1a: 1620, 1b: 1636, 1c:1610(11)) in the free Schiff base ligands to lower values of 1603-1613 cm -1 (2a: 1603, 2b: 1613, 2c: 1604 cm -1 ) in the complexes indicating the coordination of imine nitrogen to the palladium center(12)(13)(14)(15)(16). NMR evaluation of the compoundsThe 1 H NMR spectrum of complexes 2a-c displayed singlets at δ 8.59, 8.53, and 8.82 ppm, respectively, which confirmed the coordination of the imine (-CH=N) nitrogen to the palladium center (free ligands; 1a; 8.89 ppm, 1b; 8.88 ppm, and 1c; 9.57 ppm) (11,17-20).…”

mentioning

confidence: 99%

The catalytic activity of Palladium(II) complexes containing PN ligands in the Heck and Suzuki C-C coupling reactions

Yılmaz

Keleş²

2018

Journal of the Turkish Chemical Society, Section A: Chemistry

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A range of iminophosphine (PN) ligands ((C6H5)2P-C6H4-CH=NR (R=-C6H3(2-CH3)(4-OH) (1a), -CH2CH2C6H4(4-OH) (1b) and -C5H3N(2-CH3) (1c)) have been synthesized starting from 4-amino-3-methylphenol, 4-(2-aminoethyl)phenol and 2-amino-3-methylpyridine with 2-(diphenylphosphino)benzaldehyde. The PN ligands were reacted with Pd(cod)Cl2 to give corresponding new Pd(PN)Cl2 metal complexes, (2a, 2b and 2c). The Heck and Suzuki C-C coupling reactions were examined with catalysts 2a-2c and showed high conversions under the determined conditions with para substituted aryl halides.

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Ruthenium catalyzed asymmetric transfer hydrogenation based on chiral P,N,O Schiff base ligands and crystal structure of a ruthenium(II) complex bearing chiral P,N,O Schiff base ligands

Cited by 35 publications

References 29 publications

Chiral Tridentate Ligands in Transition Metal-Catalyzed Asymmetric Hydrogenation

Chiral Tridentate Ligands in Transition Metal-Catalyzed Asymmetric Hydrogenation

Structural Studies of an Array of Mixed Diamine Phosphine Ruthenium(II) Complexes¹

The catalytic activity of Palladium(II) complexes containing PN ligands in the Heck and Suzuki C-C coupling reactions

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Ruthenium catalyzed asymmetric transfer hydrogenation based on chiral P,N,O Schiff base ligands and crystal structure of a ruthenium(II) complex bearing chiral P,N,O Schiff base ligands

Cited by 35 publications

References 29 publications

Chiral Tridentate Ligands in Transition Metal-Catalyzed Asymmetric Hydrogenation

Chiral Tridentate Ligands in Transition Metal-Catalyzed Asymmetric Hydrogenation

Structural Studies of an Array of Mixed Diamine Phosphine Ruthenium(II) Complexes1

The catalytic activity of Palladium(II) complexes containing PN ligands in the Heck and Suzuki C-C coupling reactions

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Structural Studies of an Array of Mixed Diamine Phosphine Ruthenium(II) Complexes¹