Chemistry Commons^™

Enantiomeric Selective Adsorption Of Amino Acid By Polysaccharide Composite Materials, Simon Duri, Chieu D. Tran

Chemistry Faculty Research and Publications

A composite containing cellulose (CEL) and chitosan (CS) synthesized by a simple and recyclable method by using butylmethylimmidazolium chloride, an ionic liquid, was found to exhibit remarkable enantiomeric selectivity toward the adsorption of amino acids. The highest adsorption capacity and enantiomeric selectivity are exhibited by 100% CS. A racemic amino acid can be enantiomerically resolved by 100% CS in about 96–120 h. Interestingly, adsorption by 50:50 CEL/CS is more similar to that by 100% CS than to 100% CEL. Specifically, whereas 100% CEL has the lowest adsorption capacity and enantiomeric selectivity, 50:50 CEL/CS has sufficient enantiomeric selectivity to enable it …

Assembly, Structure, And Reactivity Of Cu4S And Cu3S Models For The Nitrous Oxide Reductase Active Site, CuZ*, Brittany J. Johnson, Sergey V. Lindeman, Neal P. Mankad

Chemistry Faculty Research and Publications

Bridging diphosphine ligands were used to facilitate the assembly of copper clusters with single sulfur atom bridges that model the structure of the Cu_Z* active site of nitrous oxide reductase. Using bis(diphenylphosphino)amine (dppa), a [Cu^I₄(μ₄-S)] cluster with N–H hydrogen bond donors in the secondary coordination sphere was assembled. Solvent and anion guests were found docking to the N–H sites in the solid state and in the solution phase, highlighting a kinetically viable pathway for substrate introduction to the inorganic core. Using bis(dicyclohexylphosphino)methane (dcpm), a [Cu^I₃(μ₃-S)] cluster was assembled …

Mixed Quantum/Classical Theory For Inelastic Scattering Of Asymmetric-Top-Rotor + Atom In The Body-Fixed Reference Frame And Application To The H2O + He System, Alexander Semenov, Marie-Lise Dubernet, Dmitri Babikov

Chemistry Faculty Research and Publications

The mixed quantum/classical theory (MQCT) for inelastic molecule-atom scattering developed recently [A. Semenov and D. Babikov, J. Chem. Phys.139, 174108 (2013)] is extended to treat a general case of an asymmetric-top-rotor molecule in the body-fixed reference frame. This complements a similar theory formulated in the space-fixed reference-frame [M. Ivanov, M.-L. Dubernet, and D. Babikov, J. Chem. Phys.140, 134301 (2014)]. Here, the goal was to develop an approximate computationally affordable treatment of the rotationally inelastic scattering and apply it to H₂O + He. We found that MQCT is somewhat less accurate at lower scattering energies. For example, below E …

Probing The Human Estrogen Receptor-Α Binding Requirements For Phenolic Mono- And Di-Hydroxyl Compounds: A Combined Synthesis, Binding And Docking Study, Christopher Mccullough, Terrence S. Neumann, Jayapal Reddy Gone, Zhengjie He, Christian Herrild, Julie Lukesh, Rajesh K. Pandey, William A. Donaldson, Daniel S. Sem

Chemistry Faculty Research and Publications

Various estrogen analogs were synthesized and tested for binding to human ERα using a fluorescence polarization displacement assay. Binding affinity and orientation were also predicted using docking calculations. Docking was able to accurately predict relative binding affinity and orientation for estradiol, but only if a tightly bound water molecule bridging Arg394/Glu353 is present. Di-hydroxyl compounds sometimes bind in two orientations, which are flipped in terms of relative positioning of their hydroxyl groups. Di-hydroxyl compounds were predicted to bind with their aliphatic hydroxyl group interacting with His524 in ERα. One nonsteroid-based dihdroxyl compound was 1000-fold specific for ERβ over ERα, and …

Comment On “Synthesis, Characterization, And Structures Of Persistent Aniline Radical Cation”: It Is A Protonated Aniline And Not An Aniline Radical Cation, Marat R. Talipov, Jeewantha S. Hewage, Sergey V. Lindeman, James R. Gardinier, Rajendra Rathore

Chemistry Faculty Research and Publications

The same, but different: The reaction of tri-tert-butylaniline (TBA) with AgSbF₆ in CH₂Cl₂ produces a green-colored intermediate which undergoes decomposition to form a protonated aniline (TBAH⁺SbF₆⁻). Crystals of the protonated aniline salt (see picture) were analyzed by X-ray diffraction and found to have the same crystal characteristics as the crystals of the supposed cation radical first identified in 2012.

Using Resonance Raman Cross-Section Data To Estimate The Spin State Populations Of Cytochromes P450, Piotr J. Mak, Qianhong Zhu, James R. Kincaid

Chemistry Faculty Research and Publications

The cytochromes P450 (CYPs) are heme proteins responsible for the oxidation of xenobiotics and pharmaceuticals and the biosynthesis of essential steroid products. In all cases, substrate binding initiates the enzymatic cycle, converting ferric low-spin to high-spin state, with the efficiency of the conversion varying widely for different substrates, so documentation of this conversion for a given substrate is an important objective. Resonance Raman (rR) spectroscopy can effectively yield distinctive frequencies for the ν₃ ‘spin state marker’ bands. Here, employing a reference cytochrome P450 (CYP101), the intensities of the ν₃ modes (I_LS) and (I_{HS …}

On Molecular Origin Of Mass-Independent Fractionation Of Oxygen Isotopes In The Ozone Forming Recombination Reaction, Mikhail V. Ivanov, Dmitri Babikov

Chemistry Faculty Research and Publications

Theoretical treatment of ozone forming reaction is developed within the framework of mixed quantum/classical dynamics. Formation and stabilization steps of the energy transfer mechanism are both studied, which allows simultaneous capture of the delta zero-point energy effect and η-effect and identification of the molecular level origin of mass-independent isotope fractionation. The central role belongs to scattering resonances; dependence of their lifetimes on rotational excitation, asymmetry; and connection of their vibrational wave functions to two different reaction channels. Calculations, performed within the dimensionally reduced model of ozone, are in semiquantitative agreement with experiment.

Reactive Pathways In The Chlorobenzene–Ammonia Dimer Cation Radical: New Insights From Experiment And Theory, Scott A. Reid

Chemistry Faculty Research and Publications

Building upon our recent studies of noncovalent interactions in chlorobenzene and bromobenzene clusters, in this work we focus on interactions of chlorobenzene (PhCl) with a prototypical N atom donor, ammonia (NH₃). Thus, we have obtained electronic spectra of PhCl···(NH₃)_n (n = 1–3) complexes in the region of the PhCl monomer S₀ −S₁ (ππ*) transition using resonant 2-photon ionization (R2PI) methods combined with time-of-flight mass analysis. Consistent with previous studies, we find that upon ionization the PhCl···NH₃ dimer cation radical reacts primarily via Cl atom loss. A second channel, HCl loss, is …

Syntheses And Structures Of Iron(Ii) And Cobalt(Ii) Complexes Of Substituted Tetra(Pyrazolyl)Lutidine Derivatives, Heidi Marie Tatlock

Master's Theses (2009 -)

Pentadentate ligands provide stability to metal complexes as well as a binding site for substrates that make them exceptionally useful for studying reactions. They have been used in biomimetic studies, water splitting, and small molecule activation studies. A series of six pentadentate ligands derived from a,a,a',a'-tetra(pyrazolyl)lutidine, pz4lut, with methyl substituents decorating the ligand periphery has been synthesized. These ligands were coordinated to FeIICl, and the electronic and structural properties of the resulting complexes were studied in order to deduce the effects of methyl substitution at the 3-, 4-, and 5-positions of the pyrazolyl groups and at the methine positions. When …

Synthesis, Characterization And Application Of Two-Dimensional Layered Metal Hydroxides For Environmental Remediation Purposes, Cleopas Machingauta

Dissertations (1934 -)

Two-dimensional layered nano composites, which include layered double hydroxides (LDHs), hydroxy double salts (HDSs) and layered hydroxide salts (LHSs) are able to intercalate different molecular species within their gallery space. These materials have a tunable structural composition which has made them applicable as fire retardants, adsorbents, catalysts, catalyst support materials, and ion exchangers. Thermal treatment of these materials results in destruction of the layers and formation of mixed metal oxides (MMOs) and spinels. MMOs have the ability to adsorb anions from solution and may also regenerate layered structures through a phenomenon known as “memory effect”. Zinc-nickel hydroxy nitrate was used …

Nmr And Computational Characterization Of Protein Structure And Ligand Binding, Terrence Neumann

Dissertations (1934 -)

Nuclear magnetic resonance (NMR) techniques combined with computational methods such as docking and cheminformatics were used to characterize protein structure and ligand binding. The thioredoxin system of Mycobacterium tuberculosis consists of a thioredoxin reductase and at least three thioredoxins. This system is responsible for maintaining the cellular protein thiol redox state in normal state. This maintenance is important as the bacterium is engulfed by the human macrophage. Here it is bombarded by reactive oxygen and nitrogen species in an attempt to disrupt normal cellular function in part by perturbing the protein thiols. To this end, the solution structures of the …

Preparation Of Cyclohexenones From Acyclic (Pentadienyl)Iron(1+) Cations: Synthesis Of Carvone Metabolites And Synthetic Studies Directed Toward Dihydrotachysterols, Charles Felix Manful

Dissertations (1934 -)

ABSTRACT

PREPARATION OF CYCLOHEXENONES FROM ACYCLIC (PENTADIENYL)IRON(1+) CATIONS: SYNTHESIS OF CARVONE METABOLITES AND SYNTHETIC STUDIES DIRECTED TOWARD DIHYDROTACHYSTEROLS

Charles Felix Manful, BSc.

Marquette University, 2013

Six-membered carbocycles are abundant in natural products. This structural feature is present in terpenes, secosteroids, antibiotics, and even imbedded in the polycyclic framework of complex alkaloids. A wide variety of methodologies have been utilized for the preparation of six-membered carbocycles including Robinson annulation, Diels-Alder cycloaddition, Dieckmann condensation, ring closing metathesis, photochemical carbonylation of alkenylcyclopropanes, addition of soft nucleophiles to acyclic (ç5-pentadienyl)iron cations, etc.

Acyclic (ç5-pentadienyl)iron(+1) cations were first prepared about 50 years ago. The reactivity …

Supramolecular Polysaccharide Composite Materials: Green And Recyclable Synthesis, Characterization, Analytical And Biomedical Applications, Simon Duri

Dissertations (1934 -)

A simple novel recyclable synthetic method was successfully developed for the synthesis of polysaccharide composite materials. The method involves the use of 1-butyl-3-methylimidazolium chloride [BMIm+Cl-], a simple ionic liquid, as the sole solvent. Naturally abundant and renewable materials such as cellulose (CEL) and chitosan (CS) were used for the preparation of the composite materials. CEL is the most abundant compound on earth, while CS is a product of deacetylation of chitin, which is the second most abundant material on earth. [BMIm+Cl-] is relatively non toxic, non volatile and stable over a wide range of temperature eliminating one of the major …

Intramolecular Hydrogen Bonding In CuIi Complexes With 2,6-Pyridinedicarboxamide Ligands: Synthesis, Structural Characterization, And Physical Properties, Denan Wang, Sergey V. Lindeman, Adam T. Fiedler

Chemistry Faculty Research and Publications

The significance of second-sphere interactions in synthetic catalysts and metalloenzyme active sites has encouraged the development of ligand frameworks capable of supporting intramolecular hydrogen-bonding networks. With this approach in mind, we prepared a series of 2,6-pyridinedicarboxamide ligands (H₂L^X) that feature outer-sphere heterocyclic groups (pyridine, pyrimidine, or quinoline rings). Reaction with CuCl₂ yields complexes with the general formula [CuCl₂(L^X{H}₂)] (1^X), in which the pincer ligands coordinate to the Cu^II center in a tridentate fashion through the central pyridine and two amidato nitrogen atoms. The L^{X …}

Π-Stacking, C–H/Π, And Halogen Bonding Interactions In Bromobenzene And Mixed Bromobenzene–Benzene Clusters, Scott A. Reid, Silver Nyambo, Lloyd Muzangwa, Brandon Uhler

Chemistry Faculty Research and Publications

Noncovalent interactions play an important role in many chemical and biochemical processes. Building upon our recent study of the homoclusters of chlorobenzene, where π–π stacking and CH/π interactions were identified as the most important binding motifs, in this work we present a study of bromobenzene (PhBr) and mixed bromobenzene–benzene clusters. Electronic spectra in the region of the PhBr monomer S₀–S₁ (ππ*) transition were obtained using resonant two-photon ionization (R2PI) methods combined with time-of-flight mass analysis. As previously found for related systems, the PhBr cluster spectra show a broad feature whose center is red-shifted from the monomer absorption, …

Photoisomerization And Photoinduced Reactions In Liquid Ccl4 And Chcl3, Scott A. Reid, Fawzi Abou-Chahine, Thomas J. Preston, Greg T. Dunning, Andrew J. Orr-Ewing, Gregory M. Greetham, Ian P. Clark, Mike Towrie

Chemistry Faculty Research and Publications

Transient absorption spectroscopy is used to follow the reactive intermediates involved in the first steps in the photochemistry initiated by ultraviolet (266-nm wavelength) excitation of solutions of 1,5-hexadiene, isoprene, and 2,3-dimethylbut-2-ene in carbon tetrachloride or chloroform. Ultraviolet and visible bands centered close to 330 and 500 nm in both solvents are assigned respectively to a charge transfer band of Cl-solvent complexes and the strong absorption band of a higher energy isomeric form of the solvent molecules (iso-CCl₃–Cl or iso-CHCl₂–Cl). These assignments are supported by calculations of electronic excitation energies. The isomeric forms have …

In Situ Study Of The Photodegradation Of Carbofuran Deposited On Tio2 Film Under Uv Light, Using Atr-Ftir Coupled To Hs-Mcr-Als, Abderrahman Atifi, Kazimierz Czarnecki, Hafida Mountacer, Michael D. Ryan

Chemistry Faculty Research and Publications

The in situ study of the photodegradation of carbofuran deposited on a TiO₂ catalyst film under UV light was carried out using the ATR-FTIR technique. The data were analyzed using a Hard–Soft Multivariate Curve Resolution-Alternating Least Squares (HS-MCR-ALS) methodology. Using S-MCR-ALS, four factors were deduced from the evolving factor analysis of the data, and their concentrations and spectra were determined. These results were used to draw qualitative and quantitative analyses of the major products of carbofuran photodegradation. The results of this analysis were in good agreement with GC-MS results and with reported mechanisms. Hard-MCR-ALS was then used to refine …

Recyclable Synthesis, Characterization, And Antimicrobial Activity Of Chitosan-Based Polysaccharide Composite Materials, Chieu D. Tran, Simon Duri, April L. Harkins

Chemistry Faculty Research and Publications

We have successfully developed a simple and totally recyclable method to synthesize novel, biocompatible, and biodegradable composite materials from cellulose (CEL) and chitosan (CS). In this method, [BMIm⁺Cl⁻], an ionic liquid (IL), was used as a green solvent to dissolve and synthesize the [CEL+CS] composites. Since, the IL can be removed from the composites by washing them with water, and recovered by distilling the washed solution, the method is totally recyclable. Spectroscopic and imaging techniques including XRD, FTIR, NIR, and SEM were used to monitor the dissolution, to characterize and to confirm that CEL and CS …

Cyclic Versus Polymeric Supramolecular Architectures In Metal Complexes Of Dinucleating Ligands: Silver(I) Trifluoromethanesulfonate Complexes Of The Isomers Of Bis(Di(1h-Pyrazolyl)Methyl)-1,1′-Biphenyl, James R. Gardinier, Heidi M. Tatlock, Jeewantha S. Hewage, Sergey V. Lindeman

Chemistry Faculty Research and Publications

In the search for new examples of systems that self-assemble into cyclic metal–organic architectures, the six isomers of X,Y′-bis(di(1H-pyrazolyl)methane)-1,1′-biphenyl, L_XY, and their silver(I) trifluoromethanesulfonate complexes were prepared. Five of the six silver complexes gave crystals suitable for single crystal X-ray diffraction, with only the microcrystalline derivative of 2,3′-bis(di(1H-pyrazolyl)methane)-1,1′-biphenyl, L₂₃, proving to be unsuitable for this analysis. Of the structurally characterized silver(I) complexes, that with L₂₂ showed an unusual trans-spanning chelating coordination mode to silver. At the same time the ligand was also bound to a second silver center …

Synthetic, Spectroscopic And Dft Studies Of Iron Complexes With Iminobenzo(Semi)Quinone Ligands: Implications For O-Aminophenol Dioxygenases, Michael M. Bittner, David S. Krause, Sergey V. Lindeman, Cordina V. Popescu, Adam T. Fiedler

Chemistry Faculty Research and Publications

The oxidative CC bond cleavage of o-aminophenols by nonheme Fe dioxygenases is a critical step in both human metabolism (the kynurenine pathway) and the microbial degradation of nitroaromatic pollutants. The catalytic cycle of o-aminophenol dioxygenases (APDOs) has been proposed to involve formation of an Fe^II/O₂/iminobenzosemiquinone complex, although the presence of a substrate radical has been called into question by studies of related ring-cleaving dioxygenases. Recently, we reported the first synthesis of an iron(II) complex coordinated to an iminobenzosemiquinone (ISQ) ligand, namely, [Fe(Tp)(^tBuISQ)] (2 a; where Tp=hydrotris(3,5-diphenylpyrazol-1-yl)borate and ^{tBu …}

Case Of The Missing Isomer: Pathways For Molecular Elimination In The Photo-Induced Decomposition Of 1,1-Dibromoethane, Aimable Kalume, Lisa George, Nicole Cunningham, Scott A. Reid

Chemistry Faculty Research and Publications

We report an experimental and computational study of the photodecomposition pathways of a prototypical gem-dihalide, 1,1-dibromoethane (1,1-EDB), in the condensed phase. Following photolysis of the matrix isolated parent compound in Ar at 5 K, photoproducts are observed corresponding to Br₂ elimination (+ C₂H₄ or C₂H₂) and HBr elimination (+ vinyl bromide). The elimination products are observed in the matrix as complexes. In contrast to our recent studies of the photolysis of matrix isolated polyhalomethanes, no evidence for the iso-1,1-EDB species is found, although studies of the matrix isolated 1,1-dibromo-2,2,2-trifluoroethane analogue show that …

Preparation Of A Semiquinonate-Bridged Diiron(Ii) Complex And Elucidation Of Its Geometric And Electronic Structures, Amanda E. Baum, Sergey V. Lindeman, Adam T. Fiedler

Chemistry Faculty Research and Publications

The synthesis and crystal structure of a diiron(II) complex containing a bridging semiquinonate radical are presented. The unique electronic structure of this S = 7/2 complex is examined with spectroscopic (absorption, EPR, resonance Raman) and computational methods.

Identification Of An Active Site-Bound Nitrile Hydratase Intermediate Through Single Turnover Stopped-Flow Spectroscopy, Natalie Gumataotao, Misty L. Kuhn, Natalia Hajnas, Richard C. Holz

Chemistry Faculty Research and Publications

Stopped-flow kinetic data were obtained for the iron-type nitrile hydratase from Rhodococcus equi TG328-2 (ReNHase) using methacrylonitrile as the substrate. Multiple turnover experiments suggest a three-step kinetic model that allows for the reversible binding of substrate, the presence of an intermediate, and the formation of product. Microscopic rate constants determined from these data are in good agreement with steady state data confirming that the stopped-flow method used was appropriate for the reaction. Single turnover stopped-flow experiments were used to identify catalytic intermediates. These data were globally fit confirming a three-step kinetic model. Independent absorption spectra acquired between 0.005 …

Differential Hydrogen Bonding In Human Cyp17 Dictates Hydroxylation Versus Lyase Chemistry, Michael Gregory, Piotr J. Mak, Stephen G. Sligar, James R. Kincaid

Chemistry Faculty Research and Publications

Consequences of alternative H-bonding: Raman spectra of oxygenated intermediates of Nanodisc-incorporated human CYP17 in the presence of natural substrates (pregnenolone and progesterone) directly confirm that substrate structure effectively alters hydrogen-bonding interactions with the critical Fe–O–O fragment and dictates its predisposition for one of two alternative reaction pathways. Such substrate control has profound physiological implications.

Rhodium Complexes Of A New Structurally Adaptive Pnn-Pincer Type Ligand, Sarath Wanniarachchi, Jeewantha S. Hewage, Sergey V. Lindeman, James R. Gardinier

Chemistry Faculty Research and Publications

A new PNN-pincer type ligand with pyrazolyl and diphenylphosphine flanking donors on a diarylamido anchor has been prepared. Its bis(tert-butyl isocyanide)rhodium(I) complex exhibits hemilabile behavior in solution, and its solid-state structure verified the elusive κ²P,N coordination mode for this type of ligand. Reactions between (PNN)Rh(CN^tBu)₂ and iodomethane afford both fac- and cis,mer-[(PNN)Rh(CN^tBu)₂(Me)](I), which further showcases the structural versatility of the ligand.

Chitosan-Cellulose Composite Materials: Preparation, Characterization And Application For Removal Of Microcystin, Chieu D. Tran, Simon Duri, Ambra Delneri, Mladen Franko

Chemistry Faculty Research and Publications

We developed a simple and one-step method to prepare biocompatible composites from cellulose (CEL) and chitosan (CS). [BMIm⁺Cl⁻], an ionic liquid (IL), was used as a green solvent to dissolve and prepare the [CEL + CS] composites. Since majority (>88%) of IL used was recovered for reuse by distilling the aqueous washings of [CEL + CS], the method is recyclable. XRD, FTIR, NIR, ¹³C CP-MAS-NMR and SEM were used to monitor the dissolution and to characterize the composites. The composite was found to have combined advantages of their components: superior mechanical strength (from CEL) …

Supramolecular Composite Materials From Cellulose, Chitosan, And Cyclodextrin: Facile Preparation And Their Selective Inclusion Complex Formation With Endocrine Disruptors, Simon Duri, Chieu D. Tran

Chemistry Faculty Research and Publications

We have successfully developed a simple one-step method of preparing high-performance supramolecular polysaccharide composites from cellulose (CEL), chitosan (CS), and (2,3,6-tri-O-acetyl)-α-, β-, and γ-cyclodextrin (α-, β-, and γ-TCD). In this method, [BMIm⁺Cl^–], an ionic liquid (IL), was used as a solvent to dissolve and prepare the composites. Because a majority (>88%) of the IL used was recovered for reuse, the method is recyclable. XRD, FT-IR, NIR, and SEM were used to monitor the dissolution process and to confirm that the polysaccharides were regenerated without any chemical modifications. It was found that unique properties …

Expulsion Of Leaving Groups From Zwitterionic Intermediates Generated Via Photochemical Electrocyclic Ring Closure Reactions And An Investigation On Tpe Oligomers, Tasnuva Shahrin

Dissertations (1934 -)

Photochemical cleavage reactions have been found widespread use in biological applications that require intracellular photochemical release of biologically active substrates such as peptides, proteins, neurotransmitters, or nucleotide phosphates. The research is to devise photoremovable protecting groups (cage compounds) that can be used to deprotect those biological substrates by irradiation. A number of photocleavage reactions have been developed in recent years which release chlorides, hydroxides, carboxylates, thiolates, and phenolates leaving groups for use in such applications. Nevertheless, photochemical elimination reactions that expel such leaving group anions remain quite uncommon. The cleavage of cage compounds via photolysis requires heterolysis of a bond …

Solution Structures Of Mycobacterium Tuberculosis Thioredoxin C And Models Of Intact Thioredoxin System Suggest New Approaches To Inhibitor And Drug Design, Andrew Lawrence Olson, Terrence S. Neumann, Sheng Cai, Daniel S. Sem

Chemistry Faculty Research and Publications

Here, we report the NMR solution structures of Mycobacterium tuberculosis (M. tuberculosis) thioredoxin C in both oxidized and reduced states, with discussion of structural changes that occur in going between redox states. The NMR solution structure of the oxidized TrxC corresponds closely to that of the crystal structure, except in the C-terminal region. It appears that crystal packing effects have caused an artifactual shift in the α4 helix in the previously reported crystal structure, compared with the solution structure. On the basis of these TrxC structures, chemical shift mapping, a previously reported crystal structure of the M. tuberculosis …

Spectral Data For "Generation Of Molecular Complexity From Cyclooctatetraene: Preparation Of Optically Active Protected Aminocycloheptitols And Bicyclo[4.4.1]Undecatriene", Mohamed F. El-Mansy, Anobick Sar, Sergey V. Lindeman, William A. Donaldson

Natural Products Synthesis via Organoiron Methodology

Spectral data created in the course of the research project. Supports specific findings in "Generation of Molecular Complexity from Cyclooctatetraene: Preparation of Optically Active Protected Aminocycloheptitols and Bicyclo[4.4.1]undecatriene".

The racemic (6-cyclo-heptadienyl)Fe(CO)₃⁺ cation ((±)-7), prepared from cyclooctatetraene, was treated with a variety of carbon and heteroatom nucleophiles. Attack took place at the less hindered C¹ dienyl carbon and decomplexation of the (cycloheptadiene)Fe(CO)₃ complexes gave products rich in functionality for further synthetic manipulation. In particular, a seven-step route was developed from racemic (6-styryl-2,4-cycloheptadien-1-yl)phthalimide ((±)-9 d) to afford the optically active aminocycloheptitols (−)-20 and …