Arene Tricarbonylchromium Complexes Research Articles

Intramolecular Pd Catalyzed Carbocyclization Reactions with Planar Chiral Arene Tricarbonyl Chromium Complexes

ortho-Butenylchlorobenzene tricarbonylchromium complexes undergo intramolecular Pd catalyzed cyclizations (Heck-reactions) without decomplexation and/or alkene isomerization. The diastereoselectivity of the alkene carbopalladation is governed by the planar chirality of the complex.

Completely diastereoselective radical reactions using arenechromium tricarbonyl complexes

Reaction of chromium tricarbonyl complexed aryl aldehydes and ketones with samarium(II) iodide and methyl acrylate results in formation of cyclic lactones as single diastereomers. Complete diastereoselectivity is demonstrated with aldehydes and ketones α or β to the aromatic ring with radical coupling directed anti to the chromium tricarbonyl moiety.

Lipase-mediated stereodivergent synthesis of both enantiomers of 4-(2,6-dimethylheptyl)benzoic acid

(S)- and (R)-Enantiomers of methyl 4-(3-hydroxy-2-methylpropyl)benzoate, obtained by enzymatic kinetic resolution of the related racemic arene(tricarbonyl)chromium complex in the vinyl acetate-PPL/;Et 2 O acylating system, have been converted in four steps into the (R)- and (S)-enantiomers of the title acid, respectively.

Synthesis of phosphonic acid ester functionalized arene chromium tricarbonyl complexes

The thermal reaction of Cr(CO) 6 with (a) diethyl phenylphosphonate and (b) tetraethyl α, α′- p-xylenediphosphonate gives the arene complexes [ η 6- C 6 H 5( PO 3 Et 2)] Cr( CO) 2 ( 1a, 34%) and [ η 6- p-C 6H 4(CH 2PO 3Et 2) 2]Cr(CO) 3 ( 1b, 46%). The spectroscopic properties of 1a and 1b are studied in detail. Reactions of 1a and 1b with bromotrimethylsilane give [ η 6-C 6H 5(PO 3(SiMe 3) 2)]Cr(CO) 3 ( 2a) and [ η 6- p-C 6H 4(PO 3(CH 2SiMe 3) 2) 2]Cr(CO) 3 ( 2b) as evidenced by 31P NMR.

A simple synthesis of 4E,7Z-tridecadien-1-yl acetate, a component of the sex pheromone of the potato mothPhtorimaea operculella (Lepidoptera:Gelehiidae)

A simple, five-step synthesis of the title compound was developed starting from commercially available 2,4-nonadienal. The overall yield of the pheromone is 29%, and the geometric purity of the Δ4 and Δ7 double bonds is ≥95%. TheZ configuration of the Δ7 bond results from the 1,4-cis-hydrogenation of the intermediate 1,4,6-undecatrien-3-ol in the presence of an (arene)chromium tricarbonyl complex, while theE configuration of the Δ4 bond arises in the Claisen-Johnson rearrangement occuring in the reaction of 1,5Z-undecadien-3-ol with trimethyl orthoacetate.

Stereodivergent C−C Bond Formation on Arene−Chromium Template: Endo-Selective Allylation by Hosomi−Sakurai Reaction

In arene-tricarbonylchromium complexes, excellent diastereocontrol at benzylic or homobenzylic sites can be achieved since the Cr(CO)3 group effectively blocks one face of the molecule and prevents approach of reagents from this direction.1 This feature has been widely utilized in designing useful synthetic strategies.2 Suitably structured substrates allow almost total diastereoselectivity even three carbons away from the complexed aromatic ring.3 In most of these instances, the reaction occurs from the exo face, i.e., the face opposite to the metal; endo-selective reactions are particularly rare.4 Herein we wish to report a completely endo-selective Hosomi-Sakurai allylation5 on the 2-arylidene-1-tetralone-Cr(CO)3 complex. The corresponding exo-adduct was obtained by an alternative sequence of reactions. In addition to displaying an unusual stereochemical preference, the TiCl4-catalyzed allylation reaction provides a prima facie evidence of out-of-plane coordination of titanium to the ketone dictating steric course of the reaction.

Asymmetric Addition of Organolithium Reagents to Prochiral Arene Tricarbonylchromium Complexes

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTAsymmetric Addition of Organolithium Reagents to Prochiral Arene Tricarbonylchromium ComplexesDavid Amurrio, Karl Khan, and E. Peter KündigView Author Information Département de Chimie Organique, Université de Genève, CH-1211 Genève 4, Switzerland Cite this: J. Org. Chem. 1996, 61, 7, 2258–2259Publication Date (Web):April 5, 1996Publication History Received29 January 1996Published online5 April 1996Published inissue 1 January 1996https://doi.org/10.1021/jo960070hCopyright © 1996 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views433Altmetric-Citations48LEARN 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 (214 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information SUBJECTS:Addition reactions,Hydrocarbons,Ligands,Reagents,Stereoselectivity Get e-Alerts

A diastereoselective synthesis of an arene chromiumtricarbonyl complex via a Dötz reaction

A highly diastereoselective in situ preparation of an arenechromium tricarbonyl complex is reported.

Resolution of racemic mixtures of chiral arenechromiumtricarbonyl complexes using a Bakerbond Chiralcel HPLC column

Racemic mixtures of eight new chiral arenechromiumtricarbonyl complexes were prepared and fully characterized by IR, 1H and 13C NMR spectroscopy, mass spectrometry and elemental analysis. These compounds, along with 25 previously reported chiral complexes were used to establish the ability of commercially available chiral HPLC columns to effect resolution of the mixtures. It was found that Bakerbond Chiralcel OD R columns, consisting of derivatized cellulose on silica gel, successfully resolve racemic mixtures of most arene complexes with good to excellent results. Some tentative patterns in the effect of functional groups and ring substitution on the separation efficiency have been identified and are discussed. Direct resolution of complex 22, ethyl- ortho-methoxybenzoate Cr(CO) 3, was performed on the semipreparative scale. The resolved enantiomers were characterized by optical rotation measurements and gave the following data: band 1, t R′1 = 77.8 min, [ α] 589 21 = +30.0 ± 4.1 °; band 2, t R′2 = 179.8 min, [ α] 589 21 = −29.5±1.0°.

Synthetic applications of arenetricarbonylchromium(0) complexes: the synthesis of polyfunctionalised thiophenes

Lithiation of thiophenetricarbonylchromium(0) complexes with butyllithium occurs preferentially at C-2/5 but when these are blocked, 3/4 lithiation is facile. Combinations of a bulky silyl (Pri3Si or ButMe2Si) blocking group at C-2/5 and remote lithiation/electrophilic quench of C-3/4 followed by desilylation/lithiation/electrophilic quench allowed the synthesis of 2,3-, 2,3,5- and 2,3,4,5-polysubstituted thiophene complexes and their derived free thiophenes.

An X-ray photoelectron spectroscopic study of arene chromium tricarbonyl complexes at 170K

Core and valence region XPS spectra of methyl-substituted benzene chromium tricarbonyl complexes have been measured at low (170K) temperature. The core levels were found to be unchanged by the addition of the electron-donating groups on the ring, whilst the shifts in the valence bands have been related to the bonding mechanisms within these compounds.

The prediction of the 19F NMR spectra of fluoro-substituted arenetricarbonylchromium complexes. Part III

A 19F NMR data set for fluoroarenetricarbonylchromium complexes has been used to compute statistical SCS values for a number of groups. When these values are used to predict the 19F NMR signal positions of these compounds they give a correlation coefficient of predicted versus observed values of 0.992 with a standard deviation of 1.89.

First Stereoselective Synthesis of Arene Chromium Tricarbonyl Complexes via the Benzannulation Reaction

First Stereoselective Synthesis of Arene Chromium Tricarbonyl Complexes via the Benzannulation Reaction

Synthons for the Parent Vinyl Carbene Complex in the Benzannulation Reaction

The benzannulation reaction of Fischer carbene complexes with alkynes to produce phenols was found not be synthetically useful for the parent vinyl carbene complex 6a. The β-silylated vinyl carbene complex 6c is more stable than the parent vinyl complex 6a and can be effectively used as a synthon for 6a since during the benzannulation the silicon migrates to the phenol function preferentially over hydrogen to give the arene chromium tricarbonyl complexes of the type 19. This reaction is general for a number of alkynes that have incorporated important functionality and is more useful for terminal alkynes than for internal alkynes. The migration of the silicon is responsible for the fact that stable arene chromium tricarbonyl complexes can be isolated from these reactions and makes possible transformations that take advantage of the activating ability of the chromium tricarbonyl group. This is demonstrated in intramolecular aromatic nucleophilic additions reactions. It is also shown in a single example that the α-silylated vinyl carbene complex 10b can in principle also serve as a synthon for the parent vinyl carbene complex 6a, since the benzannulated product can be disilylated with trifluoroacetic acid

ChemInform Abstract: The Total Synthesis of cis‐7,8‐Dihydroxy‐11,12‐dehydrocalamenene by Regio‐ and Diastereoselective Alkylation of Chiral η6‐ Arenetricarbonylchromium Complexes: An Unexpected Case of Nucleophilic Aromatic tele‐Substitution with Methoxide as a Leaving Group.

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The Total Synthesis of cis‐7,8‐Dihydroxy‐11,12‐dehydrocalamenene by Regio‐ and Diastereo‐selective Alkylation of Chiral η6‐Arenetricarbonylchromium Complexes: An Unexpected Case of Nucleophilic Aromatic tele‐Substitution with Methoxide as a Leaving Group

With complete diastereoselectivity and no loss of absolute stereochemical information, the chiral synthetic building block 1 is converted into 2, an advanced intermediate in the total synthesis of the antiinfective sesquiterpene 3. The reactivity of arene-Cr(CO)3 complexes is crucial to the synthetic strategy. TMS = SiMe3.

Diastereoselectivity in chiral (arene)tricarbonylchromium homobenzylic alcohol complexes: asymmetric synthesis of dihydroisocoumarins

Enantiomerically pure (arene)tricarbonylchromium complexes of homobenzylic ketones 3 undergo stereoselective reduction to give the corresponding alcohols, which may be transformed readily into enantiomerically pure dihydroisocoumarins.

Development of highly selective synthetic methods utilizing arenetricarbonylchromium complexes and their application to syntheses of therapeutic agents

The development of new methodologies for the stereocontrolled synthesis of complex molecules is very important for the efficient synthesis of therapeutic agents. In this review, 1) the stereocontrolled synthesis of exocyclic olefins using arene.Cr(CO)3-catalyzed 1,4-hydrogenation of conjugated diene and its application to the synthesis of prostacyclin analogs, 2) new catalytic activities of arene.Cr(CO)3 as a hydrogenation catalyst, 3) the stereocontrolled synthesis of silyl dienol ethers and dienamides using arene.Cr(CO)3-catalyzed isomerization, and 4) a novel carbon-carbon bond-forming reaction through eta 5-pentadienylchromium complexes, are described.

On the Unusual Conformation of Calix[4]arene Which Appears in the Tricarbonylchromium Complexes

Abstract The structures of arene-tricarbonylchromium complexes prepared from cone-25,26,27,28-tetrapropoxycalix[4]arene and Cr(CO)6 were studied by an X-ray crystallographic method: they showed an unusual conformation with a pair of faced gable-like roofs, which is extraordinarily transformed from a cone conformation.

Arene Chromium Tricarbonyl Catalyzed Reactions in Organic Synthesis

Arene chromium tricarbonyl complexes have been widely used in synthetic organic chemistry. In this article, catalytic activities of these complexes in hydrogenation and isomerization are discussed. Furthermore, their application to the syntheses of biologically significant compounds such as prostaglandins, sex pheromones and antitumor antibiotics is also reviewed