Planar-chiral Cyclopentadienyl Ruthenium Complex Research Articles

Synthesis of an optically active polymer containing a planar phthalimide backbone by asymmetric polymerization

Herein we present the precise design and synthesis of a novel polymer backbone that induces a helical structure through asymmetric polymerization reactions of a phthalimide-based monomer catalyzed by a planar-chiral cyclopentadienyl–ruthenium complex.

Enantio- and diastereoselective polymerization: asymmetric allylic alkylation catalyzed by a planar-chiral Cp′Ru complex

In this study, we examined the regio-, diastereo-, and enantioselective polymerization using asymmetric allylic alkylation catalyzed by a planar-chiral cyclopentadienyl-ruthenium (Cp′Ru) complex ((S)-1).

Enantio- and diastereoselective asymmetric allylic alkylation catalyzed by a planar-chiral cyclopentadienyl ruthenium complex.

We report asymmetric allylic alkylation of allylic chloride with β-diketones as the prochiral carbon nucleophiles using a planar-chiral Cp'Ru catalyst. The reaction proceeds under mild conditions; the resulting chiral products containing vicinal tertiary stereocenters are obtained with high regio-, diastereo-, and enantioselectivities. These chiral products can then be transformed into a chiral diol by controlling the four stereocentres.

New Method for Asymmetric Polymerization: Asymmetric Allylic Substitution Catalyzed by a Planar-Chiral Ruthenium Complex

A new type of asymmetric polymerization reaction by asymmetric allylic substitution catalyzed by planar-chiral cyclopentadienyl-ruthenium (Cp′Ru) complexes is described. Achiral AB-type monomers, which feature both the allylic chloride and N-alkoxyamide moieties in a single molecule, are smoothly polymerized by the catalysis of chiral ruthenium complexes with quantitative monomer conversion to afford optically active polyamides in good yields. The resulting polymers are characterized by optical rotation, circular dichroism, and 1H NMR analyses, which clearly show that the polymerization system works in a highly stereoselective manner to afford optically active polyamides with high regio- and enantioselectivities. The results revealed that the planar-chiral Cp′Ru complexes work as a highly efficient catalyst to control the stereochemistry even in the polymerization reaction.

Asymmetric Auto‐Tandem Catalysis with a Planar‐Chiral Ruthenium Complex: Sequential Allylic Amidation and Atom‐Transfer Radical Cyclization

Ru does it all: A novel example of an asymmetric auto-tandem reaction catalyzed by a planar-chiral cyclopentadienyl–ruthenium complex is described. The reaction of allylic chloride with α-haloamides provides synthetically useful, diastereomerically and enantiomerically enriched γ-lactams with multiple stereogenic centers through one-pot sequential allylic amidation/atom-transfer radical cyclization. PG=protecting group.

Enantioselective Synthesis of Allylic Esters via Asymmetric Allylic Substitution with Metal Carboxylates Using Planar-Chiral Cyclopentadienyl Ruthenium Catalysts

An asymmetric allylic substitution with sodium carboxylate using a planar-chiral cyclopentadienyl ruthenium complex has been developed. Optically active allylic esters were prepared in good yields with high regio- and enantioselectivities.

Regio- and Enantioselective Allylation of Indole Catalyzed by a Planar-chiral Cyclopentadienyl–Ruthenium Complex

Abstract The reaction of cinnamyl chloride with indole in the presence of a ruthenium catalyst possessing a planar-chiral cyclopentadienyl ligand resulted in the substitution at the 3-position of the indole ring to give a branched allylation product with high regio- and enantioselectivities. The stoichiometric reaction clearly revealed that the catalytic reaction proceeded via a π-cinnamyl intermediate.

Ruthenium-Catalyzed Regio- and Enantioselective O-Allylation

A highly regio- and enantioselective O-allylation of phenols and alcohols is described using a planar-chiral cyclopentadienyl ruthenium complex. Allylation predominantly takes place at the more substituted allylic carbon, producing high branched/linear ratios.

Regio‐ and Enantioselective O‐Allylation of Phenol and Alcohol Catalyzed by a Planar‐Chiral Cyclopentadienyl Ruthenium Complex

Design of an asymmetric catalyst: The planar-chiral cyclopentadienyl ruthenium complex shown in the scheme effectively catalyzes the reactions of unsymmetrically substituted allyl halides with phenol and alcohol to give the corresponding branched allyl ethers with high regio- and enantioselectivity. Supporting information for this article is available on the WWW under http://www.wiley-vch.de/contents/jc_2002/2008/z704457_s.pdf or from the author. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

Diastereoselectivity at chiral metal center of half-sandwich-type ruthenium complexes with planar-chiral cyclopentadienyl ligands in multiple ligand transfer reaction

The triple ligand transfer reaction between planar-chiral cyclopentadienyl–ruthenium complexes [Cp′Ru(NCMe) 3][PF 6] ( 1) (Cp′ = 1-(COOR 2)-2-Me-4-R 1C 5H 2; R 1 = Me, Ph, t-Bu) and iron complexes CpFe(CO)(L)X ( 2) (L = PMe 3, PMe 2Ph, PMePh 2, PPh 3; X = I, Br) resulted in the formation of metal-centered chiral ruthenium complexes Cp′Ru(CO)(L)X ( 3) in moderate yields with diastereoselectivities of up to 68% de. The configurations of some major diastereomers were determined to be S Cp ∗ R Ru ∗ by X-ray crystallography. The diastereoselectivity of 3 was under kinetic control and not affected by the steric effect of the substituents on the Cp′ ring of 1 and the phosphine of 2. Although the double ligand transfer reaction between [Cp′Ru{P(OMe) 3}(NCMe) 2][PF 6] ( 7) and CpFe(CO) 2X ( 8) produced Cp′Ru{P(OMe) 3}(CO)X ( 9), the selectivity at the ruthenium center was low.

Kinetic Resolution of Allyl Carbonates in Asymmetric Allylic Alkylation Catalyzed by Planar-Chiral Cyclopentadienyl-Ruthenium Complexes

Planar-chiral cyclopentadienyl-ruthenium complexes serve as effective catalysts for the kinetic resolution of racemic allylic carbonates in asymmetric allylic alkylation. The absolute configurations of the recovered carbonates and the alkylation products are dependent on the substituent on the cyclopentadienyl group at the 4-position of the ruthenium catalyst.

Stereoselective ligand-exchange reaction of planar-chiral cyclopentadienyl-ruthenium complexes: thermodynamic control of configuration at a stereogenic metal center.

The reaction of planar-chiral cyclopentadienyl-ruthenium complexes with Bu4NI resulted in the formation of iodo complexes with high diastereoselectivity (up to >99%de). The stereochemistry of the ruthenium center in the starting material did not influence the diastereoselectivity of the products. Epimerization of a diastereomerically pure sample gave a mixture of two diastereomers in the same ratio as with the ligand-exchange reaction, suggesting that the selectivity is determined by the difference in thermodynamic stability between the diastereomeric pair of iodo complexes. The ratio of the products depends on the nature of the substituent on the cyclopentadienyl ring and P ligands on the ruthenium atom. A combination of small substituents on the cyclopentadienyl group and small P ligands with strong electron-donating ability favored the formation of 2-I. The bulkiness of the substituents on the cyclopentadienyl group or of the P ligands, and low electron-donating ability of the P ligands increased the ratio of 2-II complexes to 2-I isomer.

Asymmetric catalysis of planar-chiral cyclopentadienylruthenium complexes in allylic amination and alkylation.

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTAsymmetric Catalysis of Planar-Chiral Cyclopentadienylruthenium Complexes in Allylic Amination and AlkylationYuji Matsushima, Kiyotaka Onitsuka, Teruyuki Kondo, Take-aki Mitsudo, and Shigetoshi TakahashiView Author Information The Institute of Scientific and Industrial Research Osaka University, Ibaraki, Osaka 567-0047, Japan Department of Energy and Hydrocarbon Chemistry Graduate School of Engineering, Kyoto University Sakyo-ku, Kyoto 606-8501, Japan Cite this: J. Am. Chem. Soc. 2001, 123, 42, 10405–10406Publication Date (Web):September 27, 2001Publication History Received2 June 2001Revised2 September 2001Published online27 September 2001Published inissue 1 October 2001https://doi.org/10.1021/ja016334lCopyright © 2001 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views2329Altmetric-Citations154LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit Read OnlinePDF (33 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Alcohols,Catalysts,Organic reactions,Post-translational modification,Stereoselectivity Get e-Alerts

Control of Stereochemistry at the Metal Center in Planar-Chiral Cyclopentadienyl Ruthenium Complexes with Anchor Phosphine on Complexation with Salicylideneaminato Ligands

Reactions of planar-chiral cyclopentadienyl-phosphine ruthenium complexes [η5,η1-{C5H2(Me)(R)COO(CH2)2PPh2}Ru(MeCN)2][PF6] (1a, R = Me; 1b, R = Ph) with sodium salicylideneaminato (2) led to the fo...

Highly selective induction of metal-centered chirality in the ligand exchange reaction of planar-chiral cyclopentadienyl–ruthenium complex bearing an anchor phosphine ligand

Treatment of planar-chiral cyclopentadienyl–phosphine ruthenium complexes with phosphine and phosphite induces metal-centered chirality with a high stereoselectivity (≳99 % de).

Multiple ligand transfer to planar-chiral cyclopentadienylruthenium complexes inducing metal-centered chirality

Multiple ligand transfer reaction between planar-chiral cyclopentadienylruthenium complexes [Cp′Ru(AN)3][PF6] [(Cp′ = 1-(CO2Et)-2-Me-4-RC5H2, R = Me, Ph, But, AN = acetonitrile] and iron complexes CpFe(CO)(L)X (L = PMe3, PPh3; X = I, Br) results in formation of metal-centered chiral ruthenium complexes Cp′Ru(CO)(L)X with a diastereoselectivity (de) up to 68%.

Diastereoselective π-Complexation: Reaction of Planar-chiral Cyclopentadienyl-Ruthenium Complexes with Prochiral Arenes

Abstract The reaction of (trisubstituted cyclopentadienyl)tris(acetonitrile)ruthenium complexes, [Cp′Ru(CH3CN)3][PF6], with prochiral trisubstituted arenes gave planar-chiral [Cp′Ru(arene)][PF6] complexes with a diastereoselectivity up to 46% d.e.

Synthesis and Property of Planar-chiral Cyclopentadienyl-ruthenium Complexes

Abstract The first enantiomerically pure planar-chiral cyclopentadienyl-ruthenium complexes, [CpnRu(benzene)]PF6, were synthesized (CpnH; unsymmetricaly trisubstituted cyclopentadiene), and by a photo reaction with CH3CN converted to [CpnRu(CH3CN)3]PF6, which was transformed into planar-chiral [CpnRu(arene)]PF6 by a ligand exchange reaction.