DOCSLIB.ORG

Anticancer Half-Sandwich Rhodium(III) Complexes

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Anticancer Half-Sandwich Rhodium(III) Complexes inorganics Review Anticancer Half-Sandwich Rhodium(III) Complexes Klaudia Máliková, Lukáš Masaryk and Pavel Štarha * Department of Inorganic Chemistry, Faculty of Science, Palacký University in Olomouc, 17, Listopadu 1192/12, 771 46 Olomouc, Czech Republic; [email protected] (K.M.); [email protected] (L.M.) * Correspondence: [email protected]; Tel.: +420-585-634-348 Abstract: Platinum-based anticancer drugs are most likely the most successful group of bioinorganic compounds. Their apparent disadvantages have led to the development of anticancer compounds of other noble metals, resulting in several ruthenium-based drugs which have entered clinical trials on oncological patients. Besides ruthenium, numerous rhodium complexes have been recently reported as highly potent antiproliferative agents against various human cancer cells, making them potential alternatives to Pt- and Ru-based metallodrugs. In this review, half-sandwich Rh(III) complexes are overviewed. Many representatives show higher in vitro potency than and different mechanisms of action (MoA) from the conventional anticancer metallodrugs (cisplatin in most cases) or clinically studied Ru drug candidates. Furthermore, some of the reviewed Rh(III) arenyl complexes are also anticancer in vivo. Pioneer anticancer organorhodium compounds as well as the recent advances in the field are discussed properly, and adequate attention is paid to their anticancer activity, solution behaviour and various processes connected with their MoA. In summary, this work summarizes the types of compounds and the most important biological results obtained in the field of anticancer half-sandwich Rh complexes. Keywords: rhodium; metal complexes; half-sandwich; anticancer; mechanism of action Citation: Máliková, K.; Masaryk, L.; Štarha, P. Anticancer Half-Sandwich Rhodium(III) Complexes. Inorganics 1. Introduction 2021, 9, 26. https://doi.org/10.3390/ Platinum-based drugs (e.g., cisplatin; Figure1) have been used for the treatment of inorganics9040026 various types of cancer for more than 40 years [1]. Although this class of anticancer metal- lodrugs is exceptionally successful, their application is connected with serious side effects Academic Editor: Bruno Therrien and resistance of various tumours [2,3], which incessantly motivates bioinorganic chemists to develop novel biologically active complexes derived not only from platinum [4–6], Received: 17 March 2021 but also from different d-block elements [7,8]. Among them, platinum-group metals other Accepted: 4 April 2021 than Pt are generally accepted as suitable ones for novel anticancer metallodrugs, because Published: 8 April 2021 a number of Ru, Rh, Pd, Os and Ir complexes have been reported as being highly effective against various types of cancer cells, and importantly, having higher cancer cell selectiv- Publisher’s Note: MDPI stays neutral ity and acting through different mechanisms of action (MoA) than the mentioned Pt(II) with regard to jurisdictional claims in published maps and institutional affil- drugs [9–13]. iations. Regarding the mentioned complexes of the platinum-group metals, Ru complexes NAMI-A [14], IT-139 (originally labelled as KP-1339; Figure1)[ 15] and TLD1433 [16] have already entered clinical trials on human oncology patients. These pharmacological successes make Ru one of the hottest d-block metals for bioinorganic and bioorganometallic chemists. One of the main advantages of Ru over Pt is its richer chemistry, offering more Copyright: © 2021 by the authors. structural types to be developed as new drugs for various diseases. Along with the above- Licensee MDPI, Basel, Switzerland. mentioned octahedral Ru(III) tetrachlorido complexes (NAMI-A, IT-139) and polypyridyl This article is an open access article distributed under the terms and and cyclometalated complexes (TLD1433 and other complexes [17,18]), pseudo-octahedral conditions of the Creative Commons half-sandwich Ru(II) complexes have also attracted significant attention as prospective Attribution (CC BY) license (https:// bioactive compounds [7–9,13,18]. creativecommons.org/licenses/by/ In general, half-sandwich complexes have a three-legged piano-stool arrangement 4.0/). with the three legs occupied by either three monodentate ligands or one bidentate and Inorganics 2021, 9, 26. https://doi.org/10.3390/inorganics9040026 https://www.mdpi.com/journal/inorganics Inorganics 2021, 9, 26 2 of 24 one monodentate ligand (with other rare possibilities). It is worth noting that anticancer Inorganics 2021, 9, x half-sandwich Ru(II) complexes have been followed by structurally similar (half-sandwich,2 of 25 d6) Os(II) [9,12,13], Rh(III) and Ir(III) [10,13] ones, also showing high anticancer activity and MoA distinct from Pt drugs. Figure 1. Structural formulas of the platinum-based drug cisplatin and the anticancer rutheni- Figure 1. Structural formulas of the platinum-based drug cisplatin and the anticancer ruthenium- um-based drug candidate IT-139. based drug candidate IT-139. In general, half-sandwich complexes have a three-legged piano-stool arrangement with Rhodiumthe three legs is aoccupied noble platinum-groupby either three monodentate metal which ligands is very or one rare bidentate in nature, and but the utilisationone monodentate of Rh ligand (e.g., (with in catalytic other rare convertors possibilities). and It thermocouples)is worth noting that and anticancer its compounds ishalf-sandwich widespread—e.g., Ru(II) seecomplexes [19,20]. Inhave the fieldbeen offollowed medicinal by chemistry,structurally Rh issimilar used for Rh- catalysed(half-sandwich, activation d6) Os(II) towards [9,12,13], various Rh(III) bioactive and Ir(III) organic [10,13] compoundsones, also showing [21,22 ],high and an- as the cen- tralticancer atom activity of various and MoA types distinct of bioactive from Pt Rhdrugs. complexes [10,13,23–25]. Besides half-sandwich Rh(III)Rhodium complexes is a noble (reviewed platinum-group in this work), metal highlywhich is anticancer very rare in polypyridyl nature, but the [26 ,uti-27] and bis- dimethyllisation of sulfoxidoRh (e.g., in [28 catalytic] Rh(III) convertors complexes, and and thermocouples) Rh(I) N-heterocyclic and its carbene compounds complexes is [29], havewidespread—e.g., to be mentioned see [19,20]. in this In context the field as well. of medicinal Some half-sandwich chemistry, Rh Rh is arenylused for complexes Rh-catalysed activation towards various bioactive organic compounds [21,22], and as the have been involved in a couple of reviews (anticancer catalytic [24,25], multi-targeted [13] central atom of various types of bioactive Rh complexes [10,13,23–25]. Besides or multinuclear [23] complexes). Nevertheless, a comprehensive overview discussing their half-sandwich Rh(III) complexes (reviewed in this work), highly anticancer polypyridyl structural[26,27] and types,bis-dimethyl types ofsulfoxido the used [28] ligands, Rh(III) biologicalcomplexes, activitiesand Rh(I) andN-heterocyclic MoA is missing car- in the literature,bene complexes although [29], have such to complexes be mentioned have in beenthis context intensively as well. studied Some half-sandwich since the pioneering workRh arenyl of Peruzzini, complexes Dyson have andbeen co-workersinvolved in publisheda couple of in reviews 2006 [30 (anticancer]. In this work, catalytic we provide the[24,25], systematic multi-targeted and topical [13] or review multinuclear of anticancer [23] complexes). compounds Nevertheless, of this type. a comprehen- The half-sandwich Rh(III)sive overview complexes discussing are categorised their structural according types, totypes their of nuclearitythe used ligands, and type biological of the ligandac- used (dentacity,tivities and MoA donor is atoms).missing Thein the selected literature, representatives although such complexes (usually the have most been active inten- ones) are discussedsively studied together since the with pioneering the most work important of Peruzzini, results Dyson of their and biological co-workers analyses. published in 2006 [30]. In this work, we provide the systematic and topical review of anticancer 2.compounds Mononuclear of this Complexes type. The half-sandwich Rh(III) complexes are categorised according 2.1.to their Complexes nuclearity with and Three type Monodentate of the ligand Ligands used (dentacity, donor atoms). The selected representatives (usually the most active ones) are discussed together with the most im- portantThis results structural of their type biological is in most analyses. cases represented by dichlorido complexes of the general 5 x n+ Inorganics 2021, 9, x formula [Rh(η -Cp )(L)Cl2] (Figure2), meaning that these complexes can be considered4 of 25 x as2. Mononuclear analogues of Complexes ruthenium-based RAPTA-type complexes; Cp is cyclopentadienyl or its derivatives,2.1. Complexes L with is a Three monodentate Monodentate ligand Ligands and n = 0 or 1. This structural type is in most cases represented by dichlorido complexes of the general formula [Rh(η5-Cpx)(L)Cl2]n+ (Figure 2), meaning that these complexes can be considered as analogues of ruthenium-based RAPTA-type complexes; Cpx is cyclopen- tadienyl or its derivatives, L is a monodentate ligand and n = 0 or 1. In 2006, the first anticancer Rh(III) arenyl complex [Rh(η5-Cp*)(pta)Cl2] (Figure 2, Table 1) was developed as a direct derivative of the (in those days) promising non-platinum, Ru-based drug candidate [Ru(η6-pcym)(pta)Cl2] (known as RAPTA-C); Figure 2. The general structural formula of the [Rh(5η5-Cp*)(L)Cl2]
Load more

Recommended publications
  • A Novel Series of Titanocene Dichloride Derivatives: Synthesis, Characterization and Assessment of Their
    A novel series of titanocene dichloride derivatives: synthesis, characterization and assessment of their cytotoxic properties by Gregory David Potter A thesis submitted to the Department of Chemistry in conformity with the requirements for the degree of Doctor of Philosophy Queen’s University Kingston, Ontario, Canada May, 2008 Copyright © Gregory David Potter, 2008 Abstract Although cis-PtCl2(NH3)2 (cisplatin) has been widely used as a chemotherapeutic agent, its use can be accompanied by toxic side effects and the development of drug resistance. Consequently, much research has been focused on the discovery of novel transition metal compounds which elicit elevated cytotoxicities coupled with reduced toxic side effects and non-cross resistance. Recently, research in this lab has focused on preparing derivatives of titanocene dichloride (TDC), a highly active chemotherapeutic agent, with pendant alkylammonium groups on one or both rings. Earlier results have demonstrated that derivatives containing either cyclic or chiral alkylammonium groups had increased cytotoxic activities. This research therefore investigated a new series of TDC complexes focusing specifically on derivatives bearing cyclic and chiral alkylammonium groups. A library of ten cyclic derivatives and six chiral derivatives were synthesized and fully characterized. These derivatives have undergone in vitro testing as anti-tumour agents using human lung, ovarian, and cervical carcinoma cell lines (A549, H209, H69, H69/CP, A2780, A2780/CP and HeLa). These standard cell lines represent solid tumour types for which new drugs are urgently needed. The potencies of all of the Ti (IV) derivatives varied greatly (range from 10.8 μM - >1000 μM), although some trends were observed. In general, the dicationic analogues exhibited greater potency than the corresponding monocationic derivatives.
    [Show full text]
  • Catalysis Science & Technology
    Catalysis Science & Technology Accepted Manuscript This is an Accepted Manuscript, which has been through the Royal Society of Chemistry peer review process and has been accepted for publication. Accepted Manuscripts are published online shortly after acceptance, before technical editing, formatting and proof reading. Using this free service, authors can make their results available to the community, in citable form, before we publish the edited article. We will replace this Accepted Manuscript with the edited and formatted Advance Article as soon as it is available. You can find more information about Accepted Manuscripts in the Information for Authors. Please note that technical editing may introduce minor changes to the text and/or graphics, which may alter content. The journal’s standard Terms & Conditions and the Ethical guidelines still apply. In no event shall the Royal Society of Chemistry be held responsible for any errors or omissions in this Accepted Manuscript or any consequences arising from the use of any information it contains. www.rsc.org/catalysis Page 1 of 6 CatalysisPlease doScience not adjust & Technology margins Journal Name ARTICLE Hydrophenylation of internal alkynes with boronic acids catalysed by a Ni-Zn hydroxy double salt-intercalated Received 00th January 20xx, Accepted 00th January 20xx Manuscript DOI: 10.1039/x0xx00000x anionic rhodium(III) complex www.rsc.org/ Takayoshi Hara, 1 Nozomi Fujita, 1 Nobuyuki Ichikuni, 1 Karen Wilson, 2 Adam F. Lee, 2 and Shogo Shimazu* 1 3- [Rh(OH) 6] intercalated Ni–Zn mixed basic salts (Rh/NiZn) are efficient catalysts for the hydrophenylation of internal alkynes with arylboronic acids under mild conditions.
    [Show full text]
  • Synthesis and Reactions of Ferrocene
    R Carbon Synthesis and Reactions of Ferrocene R Carbon Carbon Contents Objectives 1 Introduction 1 Preparation of ferrocene 2 Acetylation of ferrocene 7 Preparation of [Fe(η-C5H5)(η-C6H6)]PF6 10 Reaction of [Fe(η-C5H5)(η-C6H6)] PF6 with nucleophiles 12 Manuscript prepared by Dr. Almas I. Zayya, Dr. A. Jonathan Singh and Prof. John L. Spencer. School of Chemical and Physical Sciences, Victoria University of Wellington, New Zealand. R Carbon Objectives Introduction The principal aims of these experiments are to The archetypal organometallic compound provide experience in the synthesis, isolation, ferrocene, [Fe(η-C5H5)2], is of historical importance purification and characterisation of organometallic since its discovery and structural characterisation compounds. Purification techniques include in the early 1950s sparked extensive research into distillation, sublimation, chromatography and the chemistry of metal sandwich compounds.1 crystallisation. The main characterisation Two of the chemists who first proposed the correct technique used in these experiments is 1H NMR structure of ferrocene (Figure 1), Geoffrey Wilkinson spectroscopy using the benchtop Spinsolve and Ernst Otto Fischer, were awarded the Nobel spectrometer. Furthermore, students will Prize in Chemistry in 1973 for their pioneering work also develop their synthetic skills using inert on the chemistry of sandwich complexes. atmosphere techniques. Ferrocene is an example of a π-complex in which interactions between the d-orbitals of the Fe2+ metal centre with the π-orbitals of the two planar - cyclopentadienyl ligands (C5H5 ) form the metal-ligand bonds. Thus, all the carbon atoms in the cyclopentadienyl rings are bonded equally to the central Fe2+ ion. Ferrocene exhibits aromatic properties and is thermally very stable.
    [Show full text]
  • United States Patent Office Patented May 7, 1963
    3,088,959 United States Patent Office Patented May 7, 1963 1. 2 or grouping of carbon atoms which is present in cyclo 3,088,959 pentadiene. This grouping is illustrated as PROCESS OF MAKENG CYCLOPENTADEENY NECKEL, NTROSYL COMPOUNDS Robert D. Feltham, Joseph F. Anzenberger, azad Jonatian T. Carrie, Pittsburgh, Pa., assignors to The Interaa tional Nickel Company, Inc., New York, N.Y., a corpo ration of Delaware No Drawing. FiRed Sept. 1, 1960, Ser. No. 53,374 The substituent groups on the cyclopentadiene moiety 6 Clains. (C. 260-439) 0. indicated as R, R2, R3, R and R5 are any one or more The present invention relates to the production of of hydrogen atoms, halogen atoms and/or organic groups nickel compounds and, more particularly, to the produc such as aliphatic groups, aromatic groups, alicyclic groups, tion of nickel nitrosyl compounds containing a group etc. The substituent groups can also bond at two posi having the cyclopentadienyl moiety. tions. Where this occurs, groups can substitute for adja Compounds such as cyclopentadienylnickel nitrosyl, 5 cent R groups, e.g., Ra and R3 and/or R4 and R5 to form methylcyclopentadienylnickel nitrosyl and other complex indene and other condensed ring structures. nitrosyl compounds containing a cyclopentadienyl-type As mentioned hereinbefore, when carrying out the proc group have been made. Such compounds have use as ess of the present invention, the reactants are reacted in gasoline additives. When such use is contemplated, it is the presence of a base. The base can advantageously be economically imperative that the compounds be produced 20 a nitrogen base or a phosphorus base or an alkoxide of a in good yield from the most readily available and inex metal having a strong hydroxide.
    [Show full text]
  • Synthesis and Reactivity of Cyclopentadienyl Based Organometallic Compounds and Their Electrochemical and Biological Properties
    Synthesis and reactivity of cyclopentadienyl based organometallic compounds and their electrochemical and biological properties Sasmita Mishra Department of Chemistry National Institute of Technology Rourkela Synthesis and reactivity of cyclopentadienyl based organometallic compounds and their electrochemical and biological properties Dissertation submitted to the National Institute of Technology Rourkela In partial fulfillment of the requirements of the degree of Doctor of Philosophy in Chemistry by Sasmita Mishra (Roll Number: 511CY604) Under the supervision of Prof. Saurav Chatterjee February, 2017 Department of Chemistry National Institute of Technology Rourkela Department of Chemistry National Institute of Technology Rourkela Certificate of Examination Roll Number: 511CY604 Name: Sasmita Mishra Title of Dissertation: ''Synthesis and reactivity of cyclopentadienyl based organometallic compounds and their electrochemical and biological properties We the below signed, after checking the dissertation mentioned above and the official record book(s) of the student, hereby state our approval of the dissertation submitted in partial fulfillment of the requirements of the degree of Doctor of Philosophy in Chemistry at National Institute of Technology Rourkela. We are satisfied with the volume, quality, correctness, and originality of the work. --------------------------- Prof. Saurav Chatterjee Principal Supervisor --------------------------- --------------------------- Prof. A. Sahoo. Prof. G. Hota Member (DSC) Member (DSC) ---------------------------
    [Show full text]
  • United States Patent Office Patented Apr
    2,882,288 United States Patent Office Patented Apr. 14, 1959 1 2 ber and character of substituents on the cyclopentadienyl carbon ring may otherwise be varied at will. Suitable 2,882,288 organic compounds include hydrocarbon compounds hav ORGANOVANADIUM HALIDES AND PROCESS ing the requisite alicyclic cyclopentadienyl carbon ring. OF PREPARATION Examples of such hydrocarbon compounds are cyclo John C. Brantley and Edward L. Morehouse, Snyder, pentadiene, its aliphatic derivatives as for example methyl, N.Y., assignors to Union Carbide Corporation, a cor ethyl, allyl and vinyl cyclopentadiene, its aromatic deriv poration of New York atives as for example phenyl cyclopentadiene, indene and its comparable derivatives. No Drawing. Application September 23, 1953 10 The formation of a dihalide according to this invention Serial No. 381,968 may be illustrated by the reaction between cyclopenta 11 Claims. (C. 260-429) dienyl magnesium chloride and VCla. The Grignard re agent may be prepared by reacting magnesium turnings with a lower alkyl chloride in a solvent, ethyl ether, bein This invention relates to organo-metallic compounds zene or the like for example, and reacting the resulting containing vanadium as the metal component. The in solution with cyclopentadiene. The cyclopentadienyl vention includes correlated improvements and discoveries magnesium chloride thus formed is then reacted with whereby such vanadium compounds having distinctive VCl4 in a suitable liquid medium and the organo properties are obtained. vanadium dichloride (C5H5)VCl may be recovered An object of the invention is to provide organo-metallic 20 from the reaction mixture. The same compound results compounds containing vanadium as the metallic compo from reaction of cyclopentadienyl magnesium chloride nent linked to the organic component by carbon to metal with VOCl3.
    [Show full text]
  • 1,3-Cyclopentadiene 2523
    1,3-CYCLOPENTADIENE 2523 C5H6 MW: 66.10 CAS: 542-92-7 RTECS: GY1000000 METHOD: 2523, Issue 2 EVALUATION: FULL Issue 1: 15 May 1985 Issue 2: 15 August 1994 OSHA : 75 ppm PROPERTIES: liquid; d 0.8021 g/mL @ 20 °C; NIOSH: 75 ppm BP 42 °C; MP •85 °C; dimerizes to solid ACGIH: TWA 75 ppm (MP 32.5 °C); VP not available (1 ppm = 2.70 mg/m 3 @ NTP) SYNONYMS: none SAMPLING MEASUREMENT SAMPLER: SOLID SORBENT TUBE TECHNIQUE: GAS CHROMATOGRAPHY, FID (maleic anhydride on Chromosorb 104, 100 mg/50 mg) ANALYTE: 1,3-cyclopentadiene-maleic anhydride adduct (see REAGENTS, 1.) FLOW RATE: 0.01 to 0.05 L/min DISSOLUTION: 10 mL ethyl acetate; stand 15 min VOL-MIN: 1 L @ 75 ppm -MAX: 5 L INJECTION VOLUME: 5 µL SHIPMENT: routine TEMPERATURE-INJECTION: 200 °C -DETECTOR: 250 °C SAMPLE -COLUMN: 155 °C STABILITY: at least 1 week @ 25 °C [1] CARRIER GAS: N2, 30 mL/min BLANKS: 2 to 10 field blanks per set COLUMN: 3 m x 3-mm OD stainless steel packed with 5% OV-17 on 100/120 mesh Chromosorb WHP ACCURACY CALIBRATION: analyte in ethyl acetate RANGE STUDIED: 73 to 370 mg/m 3 [1] (3-L samples) RANGE: 0.2 to 1.2 mg 1,3-cyclopentadiene per sample BIAS: 3.6% ˆ OVERALL PRECISION (S rT): 0.066 [2] ESTIMATED LOD: 0.01 mg per sample [1] ACCURACY: ± 16.5% PRECISION (S r): 0.031 @ 0.3 to 1.2 mg per sample [1] APPLICABILITY: The working range is 25 to 150 ppm (67 to 400 mg/m 3) for a 3-L air sample, based on sampler capacity at high relative humidity.
    [Show full text]
  • Rhodium(Iii), and Iridium(Iii)
    Louisiana State University LSU Digital Commons LSU Historical Dissertations and Theses Graduate School 1980 Cyclometallated Compounds of Palladium(ii), Rhodium(iii), and Iridium(iii). Michael Anthony Gutierrez Louisiana State University and Agricultural & Mechanical College Follow this and additional works at: https://digitalcommons.lsu.edu/gradschool_disstheses Recommended Citation Gutierrez, Michael Anthony, "Cyclometallated Compounds of Palladium(ii), Rhodium(iii), and Iridium(iii)." (1980). LSU Historical Dissertations and Theses. 3562. https://digitalcommons.lsu.edu/gradschool_disstheses/3562 This Dissertation is brought to you for free and open access by the Graduate School at LSU Digital Commons. It has been accepted for inclusion in LSU Historical Dissertations and Theses by an authorized administrator of LSU Digital Commons. For more information, please contact [email protected]. INFORMATION TO USERS This was produced from a copy of a document sent to us for microfilming. While the most advanced technological means to photograph and reproduce this document have been used, the quality is heavily dependent upon the quality of the material submitted. The following explanation of techniques is provided to help you understand markings or notations which may appear on this reproduction. 1. The sign or “ target” for pages apparently lacking from the document photographed is “Missing Page(s)”. If it was possible to obtain the missing page(s) or section, they are spliced into the film along with adjacent pages. This may have necessitated cutting through an image and duplicating adjacent pages to assure you of complete continuity. 2. When an image on the film is obliterated with a round black mark it is an indication that the film inspector noticed either blurred copy because of movement during exposure, or duplicate copy.
    [Show full text]
  • A (Most Stable) > B > C > D
    CHEMISTRY 314-81 MIDTERM # 2 – ANSWER KEY July 10, 2002 Statistics: · Average: 47 pts (67%); · Highest: 69 pts (99%); Lowest: 26 pts (37%) · Number of students performing at or above average: 12 (46%) 1. (7 pts) Mark as true (T) or false (F) the following statements. Do not explain! · (T) The Diels-Alder reaction is a [4+2] cycloaddition process; · (T) Molecular orbitals with equal number of nodes are degenerate; · (T) Molecular orbitals with equal energies are degenerate; · (F) The Diels-Alder reaction occurs faster with electron-deficient dienes; · (F) Cyclooctatetraene is an antiaromatic molecule; · (F) Ethylene is aromatic since it has 2 p-electrons; · (T) A molecule is UV-active if it has a conjugated system; 2. Circle all that apply: A. (2 pts) We say that benzene is stabilized because: a. It has higher than expected heat of hydrogenation; b. It has lower reactivity; c. It has low boiling point; d. It has large resonance energy; B. (2 pts) According to Hückel’s Rule a system is antiaromatic if: a. It is not conjugated; b. It is not planar; c. It has 4n p-electrons; d. It is not cyclic; C. (2 pts) Conjugated Dienes: a. Are more stable than the corresponding dienes with isolated double bonds; b. Are less stable than the corresponding dienes with cumulated double bonds; c. Are UV-active; d. Give predominantly 1,2-addition products at low temperatures ; D. (2 pts) The Diels-Alder reaction: a. Is stereospecific ; b. Is regiospecific ; c. Requires an s-cis conformation of the dienophile; d. Requires an s-trans conformation of the diene; 3.
    [Show full text]
  • Download (2MB)
    https://theses.gla.ac.uk/ Theses Digitisation: https://www.gla.ac.uk/myglasgow/research/enlighten/theses/digitisation/ This is a digitised version of the original print thesis. Copyright and moral rights for this work are retained by the author A copy can be downloaded for personal non-commercial research or study, without prior permission or charge This work cannot be reproduced or quoted extensively from without first obtaining permission in writing from the author The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the author When referring to this work, full bibliographic details including the author, title, awarding institution and date of the thesis must be given Enlighten: Theses https://theses.gla.ac.uk/ [email protected] ORGANOMSTALLIG DERIVATIVES OF TITANIUM A thesis presented for the Degree of Master of Science in the University of Glasgow by Chandubhai Chunibhai Patel Chemistry Department, The Royal College of Science and Technology, Glasgow* September, 1965* ProQuest Number: 10984228 All rights reserved INFORMATION TO ALL USERS The quality of this reproduction is dependent upon the quality of the copy submitted. In the unlikely event that the author did not send a com plete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest ProQuest 10984228 Published by ProQuest LLC(2018). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States C ode Microform Edition © ProQuest LLC.
    [Show full text]
  • Principles of Chemical Reactivity on the Diels-Alder Reaction in Ionic
    Duquesne University Duquesne Scholarship Collection Electronic Theses and Dissertations Spring 1-1-2003 Principles of Chemical Reactivity on the Diels- Alder Reaction in Ionic Liquids and Lewis Acid Catalysis using Large-Scale Computations Orlando Acevedo Follow this and additional works at: https://dsc.duq.edu/etd Recommended Citation Acevedo, O. (2003). Principles of Chemical Reactivity on the Diels-Alder Reaction in Ionic Liquids and Lewis Acid Catalysis using Large-Scale Computations (Doctoral dissertation, Duquesne University). Retrieved from https://dsc.duq.edu/etd/7 This Worldwide Access is brought to you for free and open access by Duquesne Scholarship Collection. It has been accepted for inclusion in Electronic Theses and Dissertations by an authorized administrator of Duquesne Scholarship Collection. For more information, please contact [email protected]. Principles of Chemical Reactivity on the Diels-Alder Reaction in Ionic Liquids and Lewis Acid Catalysis using Large-Scale Computations A Dissertation Presented to the Bayer School of Natural and Environmental Sciences Duquesne University In partial fulfillment of the requirements for the degree of Doctor of Philosophy by Orlando Acevedo May 2003 Name Orlando Acevedo Dissertation Title Principles of Chemical Reactivity on the Diels-Alder Reaction in Ionic Liquids and Lewis Acid Catalysis using Large-Scale Computations Degree Doctor of Philosophy Date May 3, 2003 APPROVED ___________________________________________ Dr. Jeffrey D. Evanseck Dissertation Director Associate Professor of Chemistry and Biochemistry APPROVED ___________________________________________ Dr. Jeffry D. Madura Chairman, Dept. of Chemistry and Biochemistry Associate Professor of Chemistry and Biochemistry APPROVED ___________________________________________ Dr. Bruce Beaver Associate Professor of Chemistry and Biochemistry APPROVED ___________________________________________ Dr. Daniel A. Singleton Professor of Chemistry, Texas A&M University APPROVED ___________________________________________ Dr.
    [Show full text]
  • Probing the Strongest Aromatic Cyclopentadiene Ring By
    Article Cite This: Organometallics 2018, 37, 3219−3224 pubs.acs.org/Organometallics Probing the Strongest Aromatic Cyclopentadiene Ring by Hyperconjugation Qiong Xie, Tingting Sun, and Jun Zhu* State Key Laboratory of Physical Chemistry of Solid Surfaces and Collaborative Innovation Center of Chemistry for Energy Materials (iChEM), Fujian Provincial Key Laboratory of Theoretical and Computational Chemistry and Department of Chemistry, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005, People’s Republic of China *S Supporting Information ABSTRACT: Hyperconjugation, an interaction of electrons in a σ orbital or lone pair with an adjacent π or even σ antibonding orbital, can have a strong effect on aromaticity. However, most work on hyperconjugative aromaticity has been limited to main-group substituents. Here, we report a thorough density functional theory study to evaluate the aromaticity in various cyclopentadienes that contain both main-group and transition-metal substituents. Our calcula- tions reveal that the strongest aromatic cyclopentadiene ring can be achieved by the synergy of trans influence and hyperconjugation caused by transition-metal substituents. Our findings highlight the great power of transition metals and trans influence in achieving hyperconjugative aromaticity, opening an avenue to the design of other novel aromatic organometallics. ■ INTRODUCTION nonatetraene derivatives.27 Ottosson and co-workers reported Aromaticity, one of the most important concepts in chemistry, that the variation in
    [Show full text]