Synthesis and reactivity of 2-aminoethanethiolato-bridged dinuclear Ru(hmb) complexes (hmb = η6-hexamethylbenzene)

Mechanistic consideration on transfer hydrogenation with bifunctional [RuCl 2(hmb)]2/2-aminoethanethiol catalyst system

Masato Ito, Akira Watanabe, Yuji Shibata, Takao Ikariya

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

A series of dinuclear Ru(hmb) complexes with a bridging 2-aminoethanethiolato ligand (S-NH) have been newly prepared by controlling the stoichiometry of starting materials. Their catalytic performance in the racemization of an optically pure secondary alcohol indicated that the relative proportion of the Ru(hmb) and the S-NH unit in these catalyst precursors in addition to the amount of base as an activating agent is crucially important to generate a catalytically active species. Moreover, chiral versions of dinuclear Ru(S-NH)(hmb) complexes displayed excellent catalytic performance in terms of reactivity and enantioselectivity for the asymmetric transfer hydrogenation of aromatic ketones using HCO2H-N(C2H5) 3. In agreement with these results, the crossover experiment using a symmetrically bridged dinuclear complex, [Ru(μ-SCH2CH 2NH2)(hmb)]2Cl2, and its Cp*Ir dinuclear congener, [Cp*Ir(μ-SCH2CH2NH 2)]2Cl2 (Cp* = η5-C 5(CH3)5), suggested that the catalytic performance in the hydrogen transfer is originated from the mononuclear amido complex Ru(SCH2CH2NH)(hmb) bearing a Ru/NH bifunctionality.

Original languageEnglish
Pages (from-to)4584-4592
Number of pages9
JournalOrganometallics
Volume29
Issue number20
DOIs
Publication statusPublished - Oct 25 2010
Externally publishedYes

Fingerprint

Bearings (structural)
Cysteamine
Enantioselectivity
Ketones
Stoichiometry
Hydrogenation
hydrogenation
Hydrogen
reactivity
Alcohols
Ligands
catalysts
Catalysts
synthesis
congeners
Experiments
ketones
stoichiometry
proportion
crossovers

All Science Journal Classification (ASJC) codes

  • Physical and Theoretical Chemistry
  • Organic Chemistry
  • Inorganic Chemistry

Cite this

@article{dd3d7d09f55242ff89d7c6dec7409596,
title = "Synthesis and reactivity of 2-aminoethanethiolato-bridged dinuclear Ru(hmb) complexes (hmb = η6-hexamethylbenzene): Mechanistic consideration on transfer hydrogenation with bifunctional [RuCl 2(hmb)]2/2-aminoethanethiol catalyst system",
abstract = "A series of dinuclear Ru(hmb) complexes with a bridging 2-aminoethanethiolato ligand (S-NH) have been newly prepared by controlling the stoichiometry of starting materials. Their catalytic performance in the racemization of an optically pure secondary alcohol indicated that the relative proportion of the Ru(hmb) and the S-NH unit in these catalyst precursors in addition to the amount of base as an activating agent is crucially important to generate a catalytically active species. Moreover, chiral versions of dinuclear Ru(S-NH)(hmb) complexes displayed excellent catalytic performance in terms of reactivity and enantioselectivity for the asymmetric transfer hydrogenation of aromatic ketones using HCO2H-N(C2H5) 3. In agreement with these results, the crossover experiment using a symmetrically bridged dinuclear complex, [Ru(μ-SCH2CH 2NH2)(hmb)]2Cl2, and its Cp*Ir dinuclear congener, [Cp*Ir(μ-SCH2CH2NH 2)]2Cl2 (Cp* = η5-C 5(CH3)5), suggested that the catalytic performance in the hydrogen transfer is originated from the mononuclear amido complex Ru(SCH2CH2NH)(hmb) bearing a Ru/NH bifunctionality.",
author = "Masato Ito and Akira Watanabe and Yuji Shibata and Takao Ikariya",
year = "2010",
month = "10",
day = "25",
doi = "10.1021/om100773a",
language = "English",
volume = "29",
pages = "4584--4592",
journal = "Organometallics",
issn = "0276-7333",
publisher = "American Chemical Society",
number = "20",

}

TY - JOUR

T1 - Synthesis and reactivity of 2-aminoethanethiolato-bridged dinuclear Ru(hmb) complexes (hmb = η6-hexamethylbenzene)

T2 - Mechanistic consideration on transfer hydrogenation with bifunctional [RuCl 2(hmb)]2/2-aminoethanethiol catalyst system

AU - Ito, Masato

AU - Watanabe, Akira

AU - Shibata, Yuji

AU - Ikariya, Takao

PY - 2010/10/25

Y1 - 2010/10/25

N2 - A series of dinuclear Ru(hmb) complexes with a bridging 2-aminoethanethiolato ligand (S-NH) have been newly prepared by controlling the stoichiometry of starting materials. Their catalytic performance in the racemization of an optically pure secondary alcohol indicated that the relative proportion of the Ru(hmb) and the S-NH unit in these catalyst precursors in addition to the amount of base as an activating agent is crucially important to generate a catalytically active species. Moreover, chiral versions of dinuclear Ru(S-NH)(hmb) complexes displayed excellent catalytic performance in terms of reactivity and enantioselectivity for the asymmetric transfer hydrogenation of aromatic ketones using HCO2H-N(C2H5) 3. In agreement with these results, the crossover experiment using a symmetrically bridged dinuclear complex, [Ru(μ-SCH2CH 2NH2)(hmb)]2Cl2, and its Cp*Ir dinuclear congener, [Cp*Ir(μ-SCH2CH2NH 2)]2Cl2 (Cp* = η5-C 5(CH3)5), suggested that the catalytic performance in the hydrogen transfer is originated from the mononuclear amido complex Ru(SCH2CH2NH)(hmb) bearing a Ru/NH bifunctionality.

AB - A series of dinuclear Ru(hmb) complexes with a bridging 2-aminoethanethiolato ligand (S-NH) have been newly prepared by controlling the stoichiometry of starting materials. Their catalytic performance in the racemization of an optically pure secondary alcohol indicated that the relative proportion of the Ru(hmb) and the S-NH unit in these catalyst precursors in addition to the amount of base as an activating agent is crucially important to generate a catalytically active species. Moreover, chiral versions of dinuclear Ru(S-NH)(hmb) complexes displayed excellent catalytic performance in terms of reactivity and enantioselectivity for the asymmetric transfer hydrogenation of aromatic ketones using HCO2H-N(C2H5) 3. In agreement with these results, the crossover experiment using a symmetrically bridged dinuclear complex, [Ru(μ-SCH2CH 2NH2)(hmb)]2Cl2, and its Cp*Ir dinuclear congener, [Cp*Ir(μ-SCH2CH2NH 2)]2Cl2 (Cp* = η5-C 5(CH3)5), suggested that the catalytic performance in the hydrogen transfer is originated from the mononuclear amido complex Ru(SCH2CH2NH)(hmb) bearing a Ru/NH bifunctionality.

UR - http://www.scopus.com/inward/record.url?scp=77958101524&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=77958101524&partnerID=8YFLogxK

U2 - 10.1021/om100773a

DO - 10.1021/om100773a

M3 - Article

VL - 29

SP - 4584

EP - 4592

JO - Organometallics

JF - Organometallics

SN - 0276-7333

IS - 20

ER -