DOCSLIB.ORG

The Catalytic Decarbonylation of Aldehydes

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
The Catalytic Decarbonylation of Aldehydes THE CATALYTIC DECARBONYLATION OF ALDEHYDES USING IRON PORPHYRIN COMPLEXES By RAMESH M. BELANI B.Sc. (Hons.), BOMBAY UNIVERSITY, 1977 A THESIS SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF MASTER OF SCIENCE in THE FACULTY OF GRADUATE STUDIES DEPARTMENT OF CHEMISTRY We accept this thesis as conforming to the required standard THE UNIVERSITY OF BRITISH COLUMBIA JULY 1985 © RAMESH M. BELANI, 1985 In presenting this thesis in partial fulfilment of the requirements for an advanced degree at the University of British Columbia, I agree that the Library shall make it freely available for reference and study. I further agree that permission for extensive copying of this thesis for scholarly purposes may be granted by the head of my department or by his or her representatives. It is understood that copying or publication of this thesis for financial gain shall not be allowed without my written permission. Department of 1 The University of British Columbia 1956 Main Mall Vancouver, Canada V6T 1Y3 ii ABSTRACT The aim of this project was to investigate the use of iron porphyrin complexes as potential homogeneous catalysts for the decarbonylation of aldehydes. Complexes of the type Fe(TPP)L2 (where L = n-Bu3P, PPh3 or piperidine) were prepared and reacted with CO gas, or with aldehydes as sources of CO. Since the loss of coordinated CO from the Fe(TPP)(CO)(n-Bu3P) complex was more facile, the bis(n-Bu3P) phosphine system was studied in more detail. The X-ray structure of FeTPP(n-Bu3P)2 Is described, and this includes the first determination of an Fe^-P bond distance for a metalloporphyrin. The study using Fe(TPP)L2 complexes as decarbonylation catalysts was somewhat hindered by the extreme air-sensitivity of the porphyrin complexes in solution. UV/visible spectroscopy and gas chromatography were used to monitor the decarbonylation reactions. The reaction mixtures were analysed by GC/MS. The decarbonylation reactions were characterised by inconsistent turnover numbers and lack of reproducibility; during the decarbonylation of phenylacetaldehyde, bibenzyl was detected. Such factors are indicative of a free radical mechanism, similar to that proposed earlier for related Ru(II) porphyrin systems. The carbonylation of FeTPP(n-Bu3P)2 by CO gas was of interest with respect to the catalytic reaction, which must involve formation of a carbonyl complex. The reaction, K FeTPP(n-Bu3P)2 + CO -» FeTPP(n-Bu3P)(CO) + n-Bu3P iii was found to have a K value of 0.72 at 29°C, while the temperature dependence of K was studied to obtain the thermodynamic parameters AS and AH for the equilibrium. iv Table of Contents ABSTRACT ii Table of Contents iv List of Figures • vii List of Tables x Table of Abbreviations xii Acknowledgements xiv Chapter I INTRODUCTION 1 1.1 General introduction 1 1.2 The choice of phosphine ligand 5 1.3 The use of metalloporphyrins in decarbonylation reactions 9 1.3.1 Ruthenium (II) porphyrin complexes 10 1.3.2 Mechanism of decarbonylation using the Ru(II)TPP(PPh3)2/n-Bu3P system 16 I. 3.2 Iron (II) porphyrin complexes 19 Chapter II EXPERIMENTAL 21 II. 1 Techniques 21 II.2 Gases 21 V 11.3 Solvents 22 11.4 Other chemicals 22 11.5 Spectroscopic measurements 23 11.6 Decarbonylation procedures 26 11.7 Tetraphenylporphyrin and complexes 27 11.8 Program for gas chromatographic analysis 32 II. 8.1 Turnover numbers 34 Chapter III STRUCTURE OF FeTPP(n-Bu3P)2 35 III. l Structural analysis 35 111.2 X-ray structural analyses of metalloporphyrins .... 39 111.3 Characteristics of the Fe-Np bond distance 40 111.4 Characteristics of the M-L bond distance 45 111.4.1 Steric interactions 45 111.4.2 Degree of n-backbonding 48 111.4.3 Spin-state of metal ion 49 111.5 Model Fe-L (axial) bond distance of 6-coordinated low-spin Fe(II) tetraphenylporphyrin complexes .... 50 111.6 Conclusions 52 Chapter IV THE REACTION OF FeTPP(n-Bu3P)2 WITH CO AND 02 53 IV. 1 Reaction with CO 53 IV. 1.1 Aldehydes as sources of CO 69 IV.2 Reaction of FeTPP(n-Bu3P)2 with 02 72 vi Chapter V THE CATALYTIC DECARBONYLATION OF ALDEHYDES USING FeTPP(n-Bu3P)2 75 V.l Choice of FeTPP(n-Bu3P)2 75 V.2 Preliminary reactions with aldehydes 76 V.3 Factors influencing decarbonylation 81 V.3.1 Influence of added phosphine 81 V.3.2 Effect of CO 83 V.3.3 Effect of 02 83 V.3.4 Solvents 84 V.3.5 Varying the ratio of aldehyde to porphyrin ........ 87 V.3.6 Influence of temperature 88 V.3.7 Radical inhibitors 89 V.3.8 Rate of gas flushing 89 V.3.9 Control tests 90 V.4 Decarbonylation mechanism 90 V.4.1 The role of the phosphine ligand 94 V.5 Comparison of FeTPP(n-Bu3P)2 system with other decarbonylation systems 94 V.6 Conclusions 95 V.7 Suggestions for further studies 96 vii LIST OF FIGURES Figure 1.1 A molecular orbital picture of the bonding of a transition metal to CO and a phosphorus ligand 6 + Figure 1.2 Mechanism of decarbonylation using [Rh(P-P)2] as catalyst 8 Figure 1.3 Meso-tetraphenylporphyrin 10 Figure 1.4 Visible spectrum typical of solution no longer active for catalytic decarbonylation; that shown is for solution of Ru(TPP)(PPh3)2/(n-Bu3P) after decarbonylation of PhCH2CH0; ( ) same solution In presence of hydroquinone; inactive for decarbonylation 14 Figure 1.5 E.S.R. signals at liquid nitrogen temperature in 5:1 t CH2C12/CH3CN: A, Ru(TPP)(CO)( Bu2POH)/cyclohexen-4-al system; t B, the Ru(TPP)(CO)( Bu2POH)/pyridine-2-aldehyde system; C, the Ru(TPP)(PPh3)2/n-Bu3P/2-phenylacetaldehyde system ... 15 Figure 1.6 Proposed decarbonylation mechanism using Ru(TPP)(PPh3)2/ n-Bu3P system 18 Figure II.1 Evacuable cell for Optical Density Measurements 25 Figure III.l Stereoscopic view of FeTPP(n-Bu3P)2 structure 36 Figure III.2 A diagram illustrating the steric interactions of an axial ligand of a metalloporphyrin with the porphinato core. The dihedral angle <t> is between the plane of the ligand and the plane defined by porphinato nitrogen atom, the metal atom and the ligand nitrogen atom (N ) 45 viii Figure IV.1 UV/visible spectrum of FeTPP(n-Bu3P)2 in toluene (~ 10-ltM) 57 Figure IV.2 UV/visible spectrum of FeTPP(n-Bu3P)2 in toluene (~ I0~h M) + CO gas (0.5 - 1 atmosphere) 58 Figure IV.3 Spectral changes observed for the reaction FeTPP(C0)(n-Bu3P) + n-Bu3P ^ FeTPP(n-Bu3P)2 +. CO at 29°C 59 Ao~As Figure IV.4 Plot of log (Ae_A ) versus log [n-Bu3P], 29°C. For the CO reaction FeTPP(CO)(n-Bu3P) + n-Bu3P -—* FeTPP(n-Bu,P)0 + CO 66 1 Figure IV.5 Van't Hoff plot, LnK versus T<imnpra,„rp 68 Figure IV.6 UV/visible changes observed after addition of aldehyde to FeTPP(n-Bu3P)2 in toluene (or CH2C12). Spectral changes are reversible on vacuum pumping the optical cell 71 Figure IV.7 UV/visible spectrum of FeTPP(n-Bu3P)2 in toluene (or CH2C12) after exposure to 02 73 Figure IV.8 UV/visible changes on addition of n-Bu3P to oxidised porphyrin solution shown in IV.7 74 Figure V.l GC trace for decarbonylation of phenylacetaldehyde (~ 10_3M) _1+ using FeTPP(n-Bu3P)2 (~ 10 M) in refluxing CH2C12 (23°C) after 8 minutes 79 ix Figure V.2 GC trace of phenylacetaldehyde (~ 10-1 M) with 3 -4 FeTPP(n-Bu3P)2 (~ 10" - 10 M) in refluxing CH2C12. Product collected in cold trap 80 Figure V.3 Bibenzyl detected during decarbonylation of phenylacetaldehyde. Identification by GC/MS and comparison with computerized MS library 86 Figure V.4 Tentative decarbonylation mechanism using FeTPP(n-Bu3P)2 as catalyst 92 X LIST OF TABLES Table 1.1 Decarbonylation of aldehydes using a Ru(TPP)(PPh3)2/n-Bu3P catalyst system 12-13 Table II.1 GC retention times (mins) for standards using 0V101 column 32 Table II.2 GC retention times (mins) for standards using 0V17 column 33 Table III.l Bond lengths (A) in FeTPP(n-Bu3P)2 with estimated standard deviations in parentheses 37 Table III.2 Bond angles (deg) in FeTPP(Bu3P)2 with estimated standard deviations in parentheses 38 Table III.3 AN^ values reported for iron porphyrin complexes 41-42 Table III.4 Fe-Np bond distances in Fe-tetraphenylporphyrins 43 Table III.5 M-L bond distance changes due to steric factors 47 Table IV.1 Data used to calculate equilibrium constant for the reaction FeTPP(n-Bu3P)2 + CO —FeTPP(n-Bu3P)(CO) + (n-Bu3P) 60-65 Table IV.2 Values of [n-Bu3P] for log [Ae_^ 1 = 0, at 18-40°C 67 CD Table IV.3 Solubility of 1 atmosphere CO in toluene, corrected for vapor pressure of toluene 67 Table IV.4 Equilibrium constant (K) values for the reaction FeTPP(n-Bu3P)2 + CO =~ FeTPP(C0)(n-Bu3P) + (n-Bu3P).. 67 xl Table IV.5 Equilibrium data for reaction of Fe and Ru porphyrin complexes with CO in toluene solvent. M( porphyrin)L2 + CO M(porphyrin)(CO)L + L 69 Table IV.6 Aldehydes used as source of CO. Time required to completely form CO adduct, hours. Reaction carried out in evacuated optical cell (Figure II.1) at 23°C. Carbonyl adduct formation confirmed by UV/visible spectrum. Completion checked by extinction coefficient 70 Table V.l Decarbonylation of aldehydes with FeTPP(n-Bu3P)2 in 30 ml CH2C12 at 24°C 78 Table V.2 Effect of excess phosphine on decarbonylation of benzaldehyde in 30 ml CH2C12 at 24°C 82 Table V.3 Effect of CO on decarbonylation of benzaldehyde in 30 ml CH2C12 at 24°C 83 Table V.4 Effect of varying ratio of aldehyde to porphyrin in 30 ml CH2C12 at 24°C; argon flush 88 Table V.5 Decarbonylation of phenylacetaldehyde at 40°C in 30 ml CH2C12; argon flush 88 xii TABLE OF ABBREVIATIONS atm atmosphere A absorbance at any time, t Ae absorbance at the equilibrium position Ao absorbance of the reactant metalloporphyrin at time zero A absorbance of the metalloporphyrin product at the end CO of reaction CHjClj methylene chloride or dichloro methane CH3CN acetonitrile
Load more

Recommended publications
  • Particulate Preparation from Pisum Sativum (Plant Wax/CO Production/Hydrocarbon) T
    Proc. Natl. Acad. Sci. USA Vol. 81, pp. 6613-6617, November 1984 Biochemistry Alkane biosynthesis by decarbonylation of aldehydes catalyzed by a particulate preparation from Pisum sativum (plant wax/CO production/hydrocarbon) T. M. CHEESBROUGH AND P. E. KOLATTUKUDY* Institute of Biological Chemistry and Biochemistry/Biophysics Program, Washington State University. Pullman, WA 99164-6340 Communicated by P. K. Stumpf, June 29, 1984 ABSTRACT Mechanism of enzymatic conversion of a fat- MATERIALS AND METHODS ty acid to the corresponding alkane by the loss of the carboxyl Materials. Omnifluor, [1-_4C]stearic acid, [U-3H]tetraco- carbon was investigated with particulate preparations from Pi- sanoic acid, [1-'4Cjsteroyl-CoA, and LiAl3H4 were from sum sativum. A heavy particulate preparation (sp. gr., 1.30 New England Nuclear. Sodium [1-14C]cyanide was from g/cm3) isolated by two density-gradient centrifugation steps ICN (Chemical and Radioisotopes Division). Pyridinium catalyzed conversion of octadecanal to heptadecane and CO. chlorochromate, meso-tetraphenylporphyrin, and RhCP Experiments with [1-3H,1_14C]octadecanal showed the stoichi- 3H2O were from Aldrich. LiAIH4, di-t-butylchlorophos- ometry of the reaction and retention of the aldehydic hydrogen phine, and Ru(CO)12 were from Alfa Products. The rhodium in the alkane during this enzymatic decarbonylation. This de- chelate was synthesized by the procedure of Monson (8). carbonylase showed an optimal pH of 7.0 and a Km of 35 ,uM Ruthenium dicarbonyl tetraphenylporphyrin [Ru(CO)2- for the aldehyde. This enzyme was severely inhibited by metal (TTP)] was synthesized (9) and activated by substitution of ion chelators and showed no requirement for any cofactors.
    [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]
  • Fusing Catalase to an Alkane-Producing Enzyme
    Fusing catalase to an alkane-producing enzyme maintains enzymatic activity by converting the inhibitory byproduct H2O2 to the cosubstrate O2 Carl Andre1, Sung Won Kim, Xiao-Hong Yu, and John Shanklin2 Biosciences Department, Brookhaven National Laboratory, Upton, NY 11973 Edited by Rodney B. Croteau, Washington State University, Pullman, WA, and approved December 31, 2012 (received for review October 29, 2012) Biologically produced alkanes represent potential renewable alter- enzyme was determined as part of a structural genomics effort natives to petroleum-derived chemicals. A cyanobacterial pathway (Protein Data Bank 2OC5, Joint Center for Structural Genom- consisting of acyl–Acyl Carrier Protein reductase and an aldehyde- ics). ADO converts aldehydes to n-1 alkanes with the aldehyde C1 deformylating oxygenase (ADO) converts acyl–Acyl Carrier Pro- released as formic acid (8, 9). Electrons required for the reaction teins into corresponding n-1 alkanes via aldehyde intermediates can be provided by NADPH via ferredoxin-NADP reductase in an oxygen-dependent manner (Km for O2,84± 9 μM). In vitro, (FNR), and ferredoxin (Fd) (7), or via the chemical mediator ADO turned over only three times, but addition of more ADO to phenazine methosulfate (PMS) (10). A proposed reaction scheme exhausted assays resulted in additional product formation. While for ADO (adapted from ref. 9) is depicted below where R evaluating the peroxide shunt to drive ADO catalysis, we discov- represents Acyl: ered that ADO is inhibited by hydrogen peroxide (H2O2) with an apparent Ki of 16 ± 6 μM and that H2O2 inhibition is of mixed-type with respect to O2. Supplementing exhausted assays with catalase (CAT) restored ADO activity, demonstrating that inhibition was reversible and dependent on H2O2, which originated from poor coupling of reductant consumption with alkane formation.
    [Show full text]
  • Final Report
    FRONT PAGE PROJECT FINAL REPORT Grant Agreement number: 328996 Project acronym: HYDROACYLATION Project title: Rhodium-catalyzed alkene and alkyne hydroacylation Funding Scheme: FP7-MC-IEF Period covered: from 15/10/2013 to 14/10/2015 Name of the scientific representative of the project's co-ordinator 1 , Title and Organisation: Prof. Andrew Weller. THE CHANCELLOR, MASTERS AND SCHOLARS OF THE UNIVERSITY OF OXFORD Tel: +44 1865 285151 Fax: +44 1865 285002 E-mail: [email protected] Project websiteError! Bookmark not defined. address: 1 Usually the contact person of the coordinator as specified in Art. 8.1. of the Grant Agreement. 4.1 Final publishable summary report SUMMARY The hydroacylation reaction (HA) is a potentially powerful transformation in organic synthesis. The transformation of an aldehyde and an unsaturated hydrocarbon into a ketone involves C-H activation with C-C bond formation under atom-economical conditions. The main limitation of this reaction is the possible decarbonylation of one of the reaction intermediates. The most common catalysts for these processes are rhodium diphosphine complexes. The research proposal aimed the control of the undesirable decarbonylation pathway achiving by both attenuating decarbonylation and promoting the (rate limiting) reductive elimination step of the final product. The previous works in the host group demonstrated that hemilable ligands attenuate the decarbonylation and also complexes bearing small bite angle accelerated the main reaction. Combining these two antecedents, we have synthesized a new family of rhodium complexes containing hemilabile small bite-angle diphosphine ligands (4th generation Weller-Willis catalyst). The new rhodium complexes were excellent catalyst for the intermolecular hydroacylation of a wide variety of inactivated alkene with β-substituted aldehydes.
    [Show full text]
  • Adapting Decarbonylation Chemistry for the Development of Prodrugs Capable of in Vivo Cite This: Chem
    Chemical Science View Article Online EDGE ARTICLE View Journal | View Issue Adapting decarbonylation chemistry for the development of prodrugs capable of in vivo Cite this: Chem. Sci.,2021,12, 10649 All publication charges for this article delivery of carbon monoxide utilizing sweeteners have been paid for by the Royal Society † of Chemistry as carrier molecules Ladie Kimberly De La Cruz,‡a Xiaoxiao Yang,‡a Anna Menshikh,b Maya Brewer,b Wen Lu,a Minjia Wang,c Siming Wang,a Xingyue Ji,a Alyssa Cachuela,a Haichun Yang,d David Gallo,e Chalet Tan,c Leo Otterbein,e Mark de Caesteckerb and Binghe Wang *a Carbon monoxide as an endogenous signaling molecule exhibits pharmacological efficacy in various animal models of organ injury. To address the difficulty in using CO gas as a therapeutic agent for widespread applications, we are interested in developing CO prodrugs through bioreversible caging of CO in an organic compound. Specifically, we have explored the decarboxylation–decarbonylation chemistry of Creative Commons Attribution-NonCommercial 3.0 Unported Licence. 1,2-dicarbonyl compounds. Examination and optimization of factors favorable for maximal CO release under physiological conditions led to organic CO prodrugs using non-calorific sweeteners as leaving groups attached to the 1,2-dicarbonyl core. Attaching a leaving group with appropriate properties promotes the desired hydrolysis–decarboxylation–decarbonylation sequence of reactions that leads to CO generation. One such CO prodrug was selected to recapitulate the anti-inflammatory effects of CO against LPS-induced TNF-a production in cell culture studies. Oral administration in mice elevated COHb levels to the safe and efficacious levels established in various preclinical and clinical studies.
    [Show full text]
  • Synthesis and Characterization of Cyclopentadienyl
    Synthesis and Characterization of Cyclopentadienyl Dicarbonyldiphenylphosphinopropyliron for Migratory Insertion Polymerization by Yibo Liu A thesis presented to the University of Waterloo in fulfillment of the thesis requirement for the degree of Master of Science in Chemistry Waterloo, Ontario, Canada, 2013 © Yibo Liu 2013 1 Author's Declaration I hereby declare that I am the sole author of this thesis. This is a true copy of the thesis, including any required final revisions, as accepted by my examiners. I understand that my thesis may be made electronically available to the public. ii Abstract Metal-containing polymers (MCPs) are emerging as a class of interesting materials with promising properties and functions. Although many techniques are available for their synthesis, the range of main-chain MCPs available for material applications is limited. Most well-defined main-chain MCP syntheses rely only on the ring-opening polymerization (ROP) of metallocene monomers, thereby new synthetic approaches for novel MCPs are in high demand. In this study a new polymerization technique, migratory insertion polymerization (MIP), was explored and used to produce novel types of MCPs with asymmetric iron repeat-units connected by phosphine-iron (Ph2P-Fe) and iron-acyl (Fe-CO) bonds in the backbone. This research work involved the synthesis, characterization and polymerization of cyclopentadienyl(dicarbonyl)(diphenylphosphinopropyl)iron (FpP). FpP consists of an Fp functional group capable of undergoing a migratory insertion reaction (MIR) and a phosphine group to assist the MIR. FpP was prepared via the reaction between cyclopentadienyl dicarbonyl iron metalate (Fp anion) and (3-chloropropyl)diphenylphosphine, and was characterized using Fourier transform infrared (FTIR), 1H NMR, 31P NMR, 13C NMR, and ultraviolet-visible (UV-Vis) spectroscopies.
    [Show full text]
  • TRANSITION-METAL-CATALYZED HYDROACYLATION Vy M. Dong, Kevin G. M. Kou, and Diane N. Le Department of Chemistry, University of Ca
    TRANSITION-METAL-CATALYZED HYDROACYLATION Vy M. Dong, Kevin G. M. Kou, and Diane N. Le Department of Chemistry, University of California, Irvine, California 92697-2025, United States Vy M. Dong: [email protected] ACKNOWLEDGEMENTS Our work in this area has been supported by UC Irvine, the National Institutes of Health (GM105938), and NSERC. We also acknowledge Paul Feldman for his editorial assistance in compiling the chapter as well as Scott Denmark for the opportunity to contribute to Organic Reactions. INTRODUCTION Transition-metal catalysis has revolutionized the way natural products and medicinal targets are made. For example, asymmetric hydrogenation, olefin metathesis, and cross-coupling have evolved into indispensable tools for drug discovery. As a complement to these well-established strategies, the metal-catalyzed activation of C─H bonds is an increasingly valuable and attractive approach. In metal-catalyzed hydroacylation, an aldehyde C─H bond is oxidized to generate either a C─C bond or C─O bond, depending on the coupling partner used (e.g., alkene, alkyne, or carbonyl compound). This strategy represents an attractive, atom-economical approach for building both ketones and esters from aldehydes (Scheme 1). (1) To date, hydroacylation is most well-established for the preparation of five-membered rings, typically by rhodium catalysis. As the tether between the aldehyde and the unsaturated coupling partner becomes longer, decarbonylation becomes favored over hydroacylation. Similarly, the rate of decarbonylation is usually greater than the rate of hydroacylation in intermolecular reactions. The desired transformation is more favorable, however, when coodinating or directing groups are present on the substrate (Schemes 2 and 3).
    [Show full text]
  • Vapor Phase Decarbonylation of Furfural to Furan Over Nickel Supported on SBA-15 Silica Catalysts
    Modern Research in Catalysis, 2016, 5, 85-94 Published Online July 2016 in SciRes. http://www.scirp.org/journal/mrc http://dx.doi.org/10.4236/mrc.2016.53008 Vapor Phase Decarbonylation of Furfural to Furan over Nickel Supported on SBA-15 Silica Catalysts Diana Vargas-Hernández1*, Juan Miguel Rubio-Caballero2, Ramon Moreno-Tost2, Josefa María Mérida-Robles2, José Santamaría-González2, Antonio Jiménez-López2, María Ana Pérez-Cruz3, Rosario Hernández-Huesca3, Pedro Maireles-Torres2 1Catedrática CONACYT—Universidad de Sonora, Hermosillo, México 2Departamento de Química Inorgánica, Cristalografía y Minerología (Unidad Asociada al ICP-CSIC), Facultad de Ciencias, Universidad de Málaga, Málaga, Spain 3Facultad de Ciencias Químicas, Benemérita Universidad Autónoma de Puebla, Puebla, México Received 19 April 2016; accepted 12 July 2016; published 15 July 2016 Copyright © 2016 by authors and Scientific Research Publishing Inc. This work is licensed under the Creative Commons Attribution International License (CC BY). http://creativecommons.org/licenses/by/4.0/ Abstract Vapor-phase transformations of furfural over SBA-15 silica supported Ni catalysts under H2 in a continuous-flow reactor at atmospheric pressure and 170˚C and 230˚C were investigated. Two different samples having Ni loadings of 5 and 20 wt% (denoted here by SBA-5Ni and SBA-20Ni, respectively) were prepared by impregnation and characterized by atomic absorption spectros- copy, N2 sorption analysis, X-ray diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy. Furan and furfuryl alcohol were two primary products resulting, respective- ly, from decarbonylation and hydrogenation of furfural. Under the conditions of the study, both reactions exhibited structure sensitivity evidenced by changes in product selectivities with varia- ble Ni loadings.
    [Show full text]
  • Decarbonylation of Carboxylic Acids Over Supported Metal Catalysts
    Decarbonylation of Carboxylic Acids over Supported Metal Catalysts A Dissertation Presented to the faculty of the School of Engineering and Applied Science University of Virginia In Partial Fulfillment of the requirement for the Degree Doctor of Philosophy in Chemical Engineering by Juan A. Lopez-Ruiz September 2014 i Abstract Removal of oxygen from biomass-derived feedstocks such as carbohydrates and vegetable oil is often needed to produce chemicals and fuels. In this study, oxygen was removed from the model compounds heptanoic acid and propanoic acid by either decarboxylation, which yields carbon dioxide (CO2) and an alkane, and/or decarbonylation, which forms carbon monoxide (CO), water (H2O), and a linear alkene. Although decarbonylation produces an α-olefin as a primary product, the double bond can be isomerized to form an internal olefin or be hydrogenated to form an alkane. Recent work on decarboxylation/decarbonylation of carboxylic acids over transition metal catalysts is often performed in the presence of dihydrogen to inhibit catalyst deactivation, however, paraffins are the major product in those systems. The effects of metal type, support composition, metal loading, reaction phase, acid concentration, and conversion on activity, selectivity, and stability are presented. We studied the liquid- and gas-phase decarbonylation of carboxylic acids on Pt, Pd, and Rh nanoparticles supported on carbon and silica supports in a continuous-flow fixed-bed reactor at temperatures ranging from 533 to 573 K. The liquid-phase turnover frequency (TOF) of heptanoic acid conversion over Pt at 573 K was fairly constant, 0.0050 s-1, as the catalyst dispersion and metal loading was varied.
    [Show full text]
  • The Catalytic Decarbonylation of Unstrained Ketones Mediated by Platinum(II) Complexes
    The Catalytic Decarbonylation of Unstrained Ketones mediated by Platinum(II) Complexes Julia Paula Sarju Doctor of Philosophy University of York Chemistry September 2016 Abstract Abstract Cyclohexanone, an unstrained ketone, was found to undergo decarbonylation in the presence of soluble platinum(II) complexes of the general formula [Pt(tolpy)Cl(L)] (where tolpy is 2-(4-tolyl)pyridine and L is a neutral ligand) to afford the platinum carbonyl complex [Pt(tolpy)Cl(CO)] as well as carbon monoxide, methane and butane. As such, the activation of the cyclohexanone must proceed via the cleavage of three carbon–carbon bonds. However, the stoichiometric balance of the reaction required additional hydrogen, which implied a coupled transfer hydrogenation step. As part of a mechanistic investigation, a number of novel cycloplatinated complexes were prepared and characterised and their ability to catalyse the decarbonylation reactions was investigated. Many of them were identified as active catalyst precursors and, in particular, this was found to be true for [Pt(tolpy)Cl(CO)], suggesting that the reaction is catalytic. It was commonplace for reactions to be accompanied by decomposition to what was assumed to be colloidal platinum. In addition to cyclohexanone, a range of other carbonyl-containing substrates were investigated and examples of cyclic and acyclic ketones as well as aldehydes were found undergo decarbonylation under the conditions employed. A mechanistic investigation was undertaken involving in situ spectroscopic studies, dynamic light scattering, deuterium labelling and mercury poisoning experiments. A mechanism for the decarbonylation of cyclohexanone is proposed whereby fragmentation and transfer hydrogenation take place to afford acetaldehyde, which then undergoes decarbonylation to afford methane.
    [Show full text]
  • REVIEW Transition Metal-Catalyzed Decarbonylative Cross Coupling
    Transition-Metal-Catalyzed Decarbonylative Coupling Reactions: Concepts, Classifications, and Applications Item Type Article Authors Guo, Lin; Rueping, Magnus Citation Guo L, Rueping M (2018) Transition-Metal-Catalyzed Decarbonylative Coupling Reactions: Concepts, Classifications, and Applications. Chemistry - A European Journal. Available: http://dx.doi.org/10.1002/chem.201704670. Eprint version Post-print DOI 10.1002/chem.201704670 Publisher Wiley Journal Chemistry - A European Journal Rights Archived with thanks to Chemistry - A European Journal Download date 01/10/2021 14:00:58 Link to Item http://hdl.handle.net/10754/627922 REVIEW Transition Metal-Catalyzed Decarbonylative Cross Coupling Reactions - Concepts, Classifications and Applications Lin Guo and Magnus Rueping* Dedication ((optional)) REVIEW Abstract: Transition metal-catalyzed decarbonylative cross- coupling reactions have emerged as a powerful alternative to conventional cross-coupling protocols due to the t advantages associated with the use of carbonyl-containing functionalities as coupling electrophiles instead of commonly used organohalides or sulfates. A wide variety of novel transformations based on this concept have been successfully achieved, including decarbonylative carbon-carbon and carbon-heteroatom bond forming reactions. In this Review, we summarize the recent Scheme 1. Traditional metal-catalyzed cross-couplings versus newly- developed decarbonylative cross-couplings. progress in this field and present a comprehensive overview of metal-catalyzed decarbonylative
    [Show full text]
  • Mechanistic Studies on Aldehyde Decarbonylase from Cyanobacteria: a New Enzyme for Alkane Biosynthesis
    Mechanistic Studies on Aldehyde Decarbonylase from Cyanobacteria: A New Enzyme for Alkane Biosynthesis by Debasis Das A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Chemistry) in The University of Michigan 2014 Doctoral Committee: Professor E. Neil G. Marsh, Chair Professor Carol A. Fierke Associate Professor Nicolai Lehnert Associate Professor Bruce A. Palfey Professor Stephen W. Ragsdale @Debasis Das 2014 Dedication To my parents _ for their love, support and encouragement ii Acknowledgements I would like to take this opportunity to convey my deep gratitude to my research advisor, Prof. Neil Marsh, for his endless patience, encouragements, guidance and valuable suggestions throughout the design and accomplishment of the research described in this thesis. I would also like to express my great appreciation to Prof. Stephen Ragsdale and Prof. Carol Fierke for being extremely supportive with their guidance and for letting me use their lab facilities. I also thank Prof. Bruce Palfey, Prof. Nicolai Lehnert and Prof. Vincent Pecoraro for their valuable suggestions and guidance on my research. I would like to convey my special thanks to former Marsh lab members Dr. Dustin Patterson and Dr. Bekir Eser for being my mentors and teaching me all the necessary skills required for doing research in a biochemistry lab. I also thank the present and past Marsh group members Dr. Ben Buer, Dr. Bishwajit Paul, Dr. Fengming Lin, Dr. Yuta Suzuki, Dr. Jaehong Han, Dr. Roberto de la Saud Bea, Dr. Lei Li, Gabriel Roman, Matt Waugh, Ben Ellington, Matthew Demars, Tad Ogorzalek, Aaron Sciore, McKenna Schroeder, Dorota Marchael, Ben Levin and Umair Daimee for their productive collaborations, suggestions, friendship and for maintaining a fun-full atmosphere in the lab.
    [Show full text]