Reaction Of Tricarbonyl Research Articles

Reactivity of (1-methoxycarbonylpentadienyl)iron(1+) cations with hydride, methyl, and nitrogen nucleophiles

The reaction of tricarbonyl and (dicarbonyl)triphenylphosphine (1-methoxycarbonyl-pentadientyl)iron(1+) cations 7 and 8 with methyl lithium, NaBH3CN, or potassium phthalimide affords (pentenediyl)iron complexes 9a-c and 11a-b, while reaction with dimethylcuprate, gave (E,Z-diene)iron complexes 10 and 12. Oxidatively induced-reductive elimination of 9a-c gave vinylcyclopropanecarboxylates 17a-c. The optically active vinylcyclopropane (+)-17a, prepared from (1S)-7, undergoes olefin cross-metathesis with excess (+)-18 to yield (+)-19, a C9C16 synthon for the antifungal agent ambruticin. Alternatively reaction of 7 with methanesulfonamide or trimethylsilylazide gave (E,E-diene)iron complexes 14d and e. Huisgen [3 + 2] cyclization of the (azidodienyl)iron complex 14e with alkynes afforded triazoles 25a-e.

Preparation of Cyclohexenones from Acyclic (Pentadienyl)iron(1+) Cations: Synthetic Studies Directed toward the A‐Ring of Dihydrotachysterols

AbstractThe reaction of tricarbonyl(3‐methylpentadienyl)iron(1+) cation (7) with stabilized carbon nucleophiles affords 4‐methyl‐5‐substituted cyclohexenones. Reaction of 7 with sodium bis[(+)‐2‐phenylcyclohexyl]malonate afforded a mixture of diastereomers (de = 60 %); the diastereomeric allylic alcohols resulting from Luche reduction of this mixture were separable by column chromatography. Issues in diastereoselectivity in approaches to synthons for the A‐ring of the tachysterols from these cyclohexenones are reported.

Synthesis of mixed-valence trinuclear carbonylmanganese dithiolates: Promoting vacant coordination sites in tricarbonyl[(1-5-η)-pentadienyl]manganese

Mixed-valence complexes Mn3(CO)6(μ-S(CH2)nS-κ2-S,S′)3n = 2, 3, and 4 were prepared upon reaction of tricarbonyl[(1-5-η)-pentadienyl]manganese with the respective alkanedithiols at room temperature in good yields. The three metal centers are bound by thiolate bridges with no metal–metal bonds; one manganese atom exhibits a formal oxidation state of +4; while the other two possess an oxidation state of +1. EPR and X-ray analysis showed an octahedral environment around the manganese centers.

ChemInform Abstract: Regioselective Alkylation of (η6-Triisopropylsilylbenzene)chromium( 0) Complex with Organolithium Compounds.

Reactions of tricarbonyl(η6-triisopropylsilyl(TIPS)benzene)chromium(0) complex 1b with various alkyllithiums proceed regioselectively, giving para-substituted TIPSbenzenes in high yield after oxidation with iodine. Vinyllithiums also react with the TIPSbenzenechromium complex to give para-TIPSstyrenes in good yield. In the reaction with phenyllithium, although the para-substituted product is obtained as a main product, deprotonation of the aryl group of the chromium complex also occurs competitively to afford bisTIPSbiphenyls as a by-product. Alkynyllithium, however, attacks the TIPS group to yield alkynylsilane and TIPSbiphenyl.

Tricarbonyl[(1−5-η)-pentadienyl]manganese: A Source of Benzeneselenolatomanganese Derivatives of Diverse Nuclearity

Reaction of tricarbonyl[(1−5-η)-pentadienyl]manganese with benzeneselenol in the presence of bis(diphenylphosphino)ethane afforded a mononuclear (carbonyl)(phosphine)manganese compound with the benzeneselenolato coordinated in a terminal fashion. A dinuclear compound with two bridging selenolato ligands and a bridging carbonyl was obtained when the organometallic precursor was made to react with benzeneselenol in the presence of triphenylphosphine. Direct reaction of tricarbonyl[(1−5-η)-pentadienyl]manganese with benzeneselenol gave the heterocubane [Mn(μ3-SePh)(CO)3]4.

Phase-Transfer-Catalyzed Reaction of Tricarbonyl[η6-2-chloro-1-(trifluoromethyl)benzene]chromium with Phenylacetonitrile

The reaction of tricarbonyl[η6-2-chloro-1-(trifluoromethyl)benzene]chromium with in situ generated phenylacetonitrile anion affords two diastereomeric products, which yield α-phenyl-α-[2-(trifluoro...

ChemInform Abstract: Preparation of m‐Acylaniline Derivatives by the Reaction of Tricarbonyl(cyclohexadienone O‐benzyloxime)iron Complex and Higher Order Cuprates

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Preparation of m-Acylaniline Derivatives by the Reaction of Tricarbonyl(cyclohexadienone O-benzyloxime)iron Complex and Higher Order Cuprates

Abstract Reaction of tricarbonyl[(2,3,4,5-η)-2,4-cyclohexadien-1-one O-benzyloxime]iron and organocuprates, followed by the treatment with acetic anhydride and carbon monoxide, affords [(1,2,3,4-η)-1-(N-acetoxy-N-benzyloxyamino)-5-endo-acyl-1,3-cyclohexadiene]tricarbonylirons, which are converted to m-acylaniline derivatives by treating with potassium carbonate.

Transition metal complexes in organic synthesis. Part 46. Synthesis of 5-arylmethyl-substituted tricarbonyl(1-4-?-cyclohexa-1,3-diene)iron complexes

The reaction of tricarbonyl(η5-cyclohexadienylium) iron tetrafluoroborate 3 with the methyl arylacetate 6, the dimethyl arylmalonate 12, and the di-tert-butyl arylmalonate 14 provides regio- and stereoselectively the tricarbonyliron-complexed 5-arylmethylcyclohexa-1,3-dienes 7, 13 and 15.

ChemInform Abstract: Preparation of m‐Acylphenol Derivatives by the Reaction of Tricarbonyl( cyclohexadienone)iron Complex and Higher Order Cuprates.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Preparation of m-Acylphenol Derivatives by the Reaction of Tricarbonyl(cyclohexadienone)iron Complex and Higher Order Cuprates

Abstract Reaction of tricarbonyl[(2,3,4,5-η)-2,4-cyclohexadien-1-one]iron and higher order cuprates followed by the treatment with acetic anhydride and then with carbon monoxide affords tricarbonyl[(1,2,3,4-η)-1-acetoxy-5-endo-acyl-1,3-cyclohexadiene]iron complexes in good yield, which are converted to meta-acylphenol derivatives by the oxidation with trimethylamine N-oxide.

Nucleophilic substitution reactions of ( η6-fluorotoluene)Cr(CO) 3 and ( η6-fluoroanisole)Cr(CO) 3 toward phenylacetylide, fluorenyl, indolinyl and carbazolinyl lithium: crystal structures of tricarbonyl[ η6-(1,2-diphenylethynyl)benzene]chromium and tricarbonyl[ η6-(1,4-fluorenyl)toluene]chromium

Tricarbonyl[ η 6-(1,2-diphenylethynyl)benzene]chromium ( 8a) was obtained along with tricarbonyl[ η 6-(2-phenylethynyl)anisole]chromium ( 7b) and tricarbonyl[ η 6-(3-phenylethynyl)anisole]chromium ( 7a) from the reaction of tricarbonyl( η 6-fluoroanisol)chromium ( 4c) with lithium phenylacetylide ( 3). The formation of ortho- and meta-products, 7b, 8a and 7a, produced in the above reaction demonstrates that the reaction was by no means through a straightforward nucleophilic substitution mechanism. These results provided support for the mechanism proposed by Pauson and Brookhart, in which the nucleophile attacked the carbon atom of the phenyl ring not bearing the leaving group, followed by hydrogen migration and finally elimination of the leaving group to achieve aromaticity. 8a was obtained presumably from the reaction of 7b with excess 3. Compounds were characterized by mass, infrared, 1H, 13C NMR spectra. The molecular structure of 8a has been determined by X-ray diffraction studies. Crystal data are as follows: orthorhombic, P BCA, a = 18.690(2) A ̊ , b = 10.666(2) A ̊ , c = 20.463(2) A ̊ , V = 4079.3(8) A ̊ 3, Z = 8, R =4.41%, R w = 5.56% . Tricarbonyl( η 6-4-fluorenyltoluene)chromium ( 10) was obtained as the only separated product from the reaction of tricarbonyl[ η 6-4-flurotoluene)chromium ( 5) with fluorenyl lithium. The X-ray crystal structure of 10 was determined: monoclinic, P2 1/c, a = 12.318(1) A ̊ , b = 11.498(1) A ̊ , c = 13.585(2) A ̊ , β = 100.35(1)°, V = 1892.8(5) A ̊ 3, Z = 4, R = 3.63%, R w = 5.65% . Tricarbonyl[ η 6-4-fluorenylanisole)chromium ( 11a), tricarbonyl[ η 6-3-fluorenylanisole)chromium ( 11b) and tricarbonyl[ η 6-2-fluorenylanisole)chromium ( 11c) were also produced in moderate to good yields. Moreover, tricarbonyl[ η 6-4-indolinyltoluene)chromium ( 12) and tricarbonyl[ η 6-4-carbazolinyltoluene)chromium ( 14) were synthesized from the reaction of 5 with indolinyl and carbazolinyl lithium, respectively. Tricarbonyl[ η 6-4-indolinylanisole)chromium ( 13a), tricarbonyl[ η 6-3-indolinylanisole)chromium ( 13b) and tricarbonyl[ η 6-2-indolinylanisole)chromium ( 13c) were obtained in high yields from the direct nucleophilic substitution reactions of related compounds.

The diastereoselectivity of the addition of tricarbonyl-(η 6-2-lithiothiophene) chromium(O) complexes on aldehydes

It has been shown that the reactions of tricarbonyl(η 6 -2-lithiothiophene)chromium(O) with various arene carboxaldehydes yields mixtures of unequal amounts of diastereoisomers, which can be separated by flash chromatography. The structures of the products have been established by 1H NMR spectroscopy and by independent synthesis. A novel synthesis of tricarbonyl(η 6-thiophene)-chromium(O) ( 1) is described.

Reaction of Tricarbonyl(η3‐allyl)iron(0) Anions with Bromine

AbstractThe addition of reactive carbanions to tricarbonyl(η4‐1,3‐diene)iron(0) complexes proceeded at 23°C to give putative tricarbonyl(η3‐allyl)iron(0) anion complexes. Trapping of the reactive intermediates with bromine produced nucleophilic‐substituted tricarbonyl(η4‐1,3‐diene)iron(0) complexes.

ChemInform Abstract: Synthesis, Characterization, and Some Reactions of Tricarbonyl( cyclobutabenzene)chromium(0) Derivatives.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis, Characterization, and Some Reactions of Tricarbonyl(cyclobutabenzene)chromium(O) Derivatives

The tricarbonyl(cyclobutabenzene)chromium(O) complexes 12 – 20, have been prepared from the free ligand and triammintricarbonylchromium(O) or hexacarbonylchromium(O). The complexes have been characterized by spectroscopic methods (IR, 1H NMR, 13C NMR) and mass spectrometry, and 1H‐NMR signal assignments have been verified by an NOE experiment. Diastereomeric ratios have been determined by 1H NMR and the diastereomers of the 1‐methyl derivative 16 separated by HPLC. A crystal‐structure analysis is presented for exo;‐16. A photochemical ligand exchange takes place in 70% yield for the 1‐trimethylsilyl derivative 19. Metalation with n‐butyl‐lithium/tmeda at –78°C has been observed only for the aromatic and not for the benzylic protons.

Tricarbonylpyridinechromium complexes: stereoselective alkylations and aldol-type reactions involving α-carbanions derived from η-tricarbonyl(2-alkylpyridine)chromium complexes

Reaction of tricarbonyl(η-2-alkylpyridine)chromium(0) complexes with lithium diisopropylamide at –40 °C generates the resonance stabilised carbanions at the α-position which undergo completely stereoselective electrophilic quench with alkyl halides to generate the corresponding α-branched tricarbonyl(η-2-alkylpyridine)chromium (0) complexes. These complexes can then be subjected to nucleophilic additions with methyllithium followed by methyl iodide quench to afford the tricarbonyl(η-exo-6-alkyl-1,2-dimethyl-1,2-dihydropyridine)chromium (0) complexes. Treatment of the resonance stabilised α-carbanion derived from tricarbonyl(η-2-ethylpyridine)chromium (0) with the non-enolisable aldehydes benzaldehyde or pivalaldehyde affords the erythro-aldol-type products with complete control of stereochemistry at both the newly formed α-and carbinol centres. X-Ray crystal structures of SR(RS)-tricarbonyl[η-exo-1,2-dimethyl-6-(2-pent-4-enyl)-1,2-dihydropyridine)-chromium (0) and RSS(SRR)-tricarbonyl[erythro-2-η-(2-pyridyl)-1-phenylpropanol]chromium (0) are reported.

Preparation of tricarbonyl(.eta.4-vinylketene)iron(0) complexes from tricarbonyl(.eta.4-vinyl ketone)iron(0) complexes and their subsequent conversion to tricarbonyl(.eta.4-vinylketenimine)iron(0) complexes

Reaction of tricarbonyl (η 4 -vinyl ketone) iron (0) complexes (CO) 3 (PhCH=CHC(R)=O) Fe(0) (R=Me, Bu n , Bu t , Ph) with organolithium reagents under an atmosphere of carbon monoxide gave products that were identified as tricarbonyl «(η 4 -vinylketene)» iron (0) complexes (CO) 3 (PhCH=CHC(R)=C=O) Fe(0)

Diastereocontrol of η4-α,β-unsaturated ketone–Fe(CO)3complexation by an adjacent metal-complexed chiral centre

The reaction of tricarbonyl-[η6-3-(o-methyl- or o-methoxyphenyl)-1-phenylprop-2-en-1-onelchromium with nonacarbonyldi-iron gives specifically one diastereoisomer of the η4-Fe(CO)3–α,β-unsaturated ketone–η6 Cr(CO)3–ortho-substituted arene complex, the relative configuration (RS,SR) of which was unambiguously established by X-ray analysis; the equivalent reaction using the 3-m-methoxyphenylpropenone isomer gives a 1 : 1 mixture of two diastereoisomers.

Studies on olefin-co-ordinating transition-metal carbene complexes. Part 14. An unusual reaction of tricarbonyl(η4-cyclopenta-1,3-diene)iron: a new approach to acyldicarbonyl(η-cyclopentadienyl)iron complexes, and the X-ray crystal structure of [Fe(COC6H4CF3-p)(η-C5H5)(CO)2

Reaction of tricarbonyl(η4-cyclopenta-1,3-diene)iron (1) with aryl-lithium reagents, LiR (R = Ph, C6H4Me-o or -p, C6H4OMe-p, or C6H4CF3-p), in diethyl ether at low temperature, followed by the reaction of the acylmetalate intermediates formed with Et3OBF4 in CH2Cl2 at –60 °C or in aqueous solution at 0 °C, afforded yellow crystalline compounds formulated as [Fe(COR)(η-C5H5)(CO)2](2)–(6) based on elemental analyses, i.r., 1H n.m.r., and mass spectra. Complex (6) has been studied by X-ray diffraction: triclinic, space group P with the unit-cell constants a= 7.670(7), b= 9.008(4), c= 10.662(1)Å, α= 103.70(2), β= 96.496(8), γ= 100.03(2)°, Z= 2, R= 0.039, and R′= 0.045 for 2 834 reflections with I > 3σ(I).