DOCSLIB.ORG

Synthetic and Mechanistic Studies of Ruthenium Catalyzed C-C, C-N and C-O Bond Activation Reactions Nishantha Kumara Kalutharage Marquette University

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Synthetic and Mechanistic Studies of Ruthenium Catalyzed C-C, C-N and C-O Bond Activation Reactions Nishantha Kumara Kalutharage Marquette University Marquette University e-Publications@Marquette Dissertations (2009 -) Dissertations, Theses, and Professional Projects Synthetic and Mechanistic Studies of Ruthenium Catalyzed C-C, C-N and C-O Bond Activation Reactions Nishantha Kumara Kalutharage Marquette University Recommended Citation Kalutharage, Nishantha Kumara, "Synthetic and Mechanistic Studies of Ruthenium Catalyzed C-C, C-N and C-O Bond Activation Reactions" (2015). Dissertations (2009 -). Paper 506. http://epublications.marquette.edu/dissertations_mu/506 SYNTHETIC AND MECHANISTIC STUDIES OF RUTHENIUM CATALYZED C-C, C-N AND C-O BOND ACTIVATION REACTIONS By Nishantha Kalutharage, B.Sc. (Hons) A Dissertation Submitted to the Faculty of the Graduate School, Marquette University, in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy Milwaukee, Wisconsin May 2015 ABSTRACT SYNTHETIC AND MECHANISTIC STUDIES OF RUTHENIUM CATALYZED C-C, C-N AND C-O BOND ACTIVATION REACTIONS Nishantha Kalutharage, B.Sc. (Hons) Marquette University, 2015 Transition metal catalyzed selective C-C, C-N and C-O bond activation reactions are fundamentally important in organometallic chemistry and organic synthesis. Catalytic C-C, C-N and C-O activation are highly valuable for reforming processes of crude oils. Significant research has been devoted to transition metal mediated C-C, C-N and C-O bond cleavage reactions to form new compounds as these processes are expected to provide novel ways to transformation of inexpensive hydrocarbons into more commercially valuable products such as pharmaceuticals, agrochemicals and polymers. A few examples of transition metal catalyzed cross coupling reactions involving C- N bond cleavage have been reported. A well-defined Ru catalytic system has been developed for oxidative alkylation of alcohol by deaminative coupling reactions of amines to form alkylated ketones. The catalytic method was successfully applied to the decarboxylative and deaminative coupling of amino acids with ketones. Reductive deoxygenation of aldehydes and ketones has attracted considerable attention due to its many applications in fine-chemical synthesis and biofuel production. Classical methods for the deoxygenation of carbonyl compounds are generally associated with harsh reaction conditions and the use of stoichiometric amounts of toxic reagents, and poor functional-group tolerance. A well-defined Ru-H catalyst was found to mediate the reductive deoxygenation of carbonyl compounds to produce aliphatic compounds. Two different mechanistic pathways have been investigated in detail to probe the electronic nature of the catalysts and ligands. Reductive etherification of ketones/aldehydes and alcohols have been studied intensively as cheaper and greener ways to synthesize ethers. A method for the reductive coupling of carbonyl compounds with alcohols has been developed, which involved a highly chemoselective formation of unsymmetrically substituted ether products. The catalytic etherification method employs cheaply available molecular hydrogen as the reducing agent, tolerates a number of common functional groups, and uses environmentally benign water as the solvent. i ACKNOWLEDGMENTS Nishantha Kalutharage, B. Sc (Hons) I would like to express my special appreciation and thanks to my advisor, Professor Chae S. Yi, for his tremendous guidance during study at Marquette University. I would like to thank him for encouraging my research and for allowing me to grow as a research scientist. I would also like to thank my committee members Professors Adam Fiedler and Christopher Dockendoff, for their encouragement, insightful comments, and support. My special thanks goes to Professor William Donaldson who was on my thesis committee but is on sabbatical at the present time. I would like to thank my group members, Dr. Kwang- Min Choi, Junghwa Kim and Hanbin Lee, for being such good friends, and former group members as mentors Dr. Dong-Hwan Lee and Dr. Ki-Hyeok Kwon, for their support and valuable conversations during my first year. I thank my teachers and colleagues at the Ruhuna University, especially Dr. Sarath Wanniarachchi, who gave me precious help during my first year at Marquette. Two professors, Ruchira Cumaranatunga and Hema Pathirana, have inspired and encourage me choose chemistry as my future. My deepest gratitude goes to my parents for their unflagging love and support throughout my life. They have sacrificed their lives to provide the best possible environment for me to get the education. Most of all, I want to thank my wife Sugandhi Wasana for her love, sacrifice, and kind indulgence. To my beloved son Sandaru and daughter Hawanya, I would like to express my thanks for being such good children always cheering up, inspiring and astonishing me every day. I would like to thank ii all of my friends who have been helping me to keep my mind peacefully under difficult situations, especially Mohamed El-Mansy and Wei Hu. My gratefulness to the countless technical support from Dr. Sheng Cai (for his support and his help running special NMR studies) and Dr. Sergey Lindeman (for providing single crystal diffraction analysis data). I am extremely appreciative of the financial assistance and the research assistantship given by Marquette University, the Arthur J. Schmitt Foundation, and the National Science Foundation which provided me with more time to focus on my research. Also, I would like to thank the Graduate School and all of the Marquette University administration. iii DEDICATION I dedicate this work to my wife, son, daughter and my mother, for their patience and support. Thank you for your understanding and your love. TABLE OF CONTENTS ACKNOWLEDGEMENT………………………………………………………………...i DEDICATION……………………………………………………………………………iii LIST OF TABLES……………………………………………………………………….iv LIST OF FIGURES…………………………………………………………………..…viii LIST OF SCHEMES…………………………………………………………………….xvi CHAPTER 1 ....................................................................................................................... 1 INTRODUCTION .............................................................................................................. 1 1.1 C-C Bond Activation of Hydrocarbon Molecules................................................ 1 1.1.1 Stoichiometric C-C Bond Activation Reaction .......................................... 3 1.1.2 Catalytic C-C Bond Activation Reactions ................................................. 4 1.1.2.1 C-C Bond Activation of Strained Molecules ....................................... 4 1.1.2.2. Catalytic C-C Activation of Unstrained Molecules ............................ 7 1.1.2.3. Chelate Assisted C-C Bond Activation Reactions of Unstrained Molecules…………………………………………………………………….8 1.1.2.4 Alkene/Alkyne Insertion Reactions via C-C Bond Cleavage ............ 12 1.2. Catalytic C-N Bond Activation Reactions ................................................. 14 1.2.1 Heterogeneous Hydrodenitrogenation of Nitrogen Heterocycles ........ 14 1.2.1 Hydrodenitrogenation Reactions Catalyzed by Soluble Metal Complexes…….…………………………………………………………….14 1.2.2. Catalytic Deaminative C-N Cleavage Reactions ................................. 18 1.2.2.1 C-N Bond Cleavage of Allylic Amines…………………....…..18 1.2.2.2 C-N Cleavage of Arylamines……………………………….…22 1.2.2.3 C-N Cleavage of Secondary and Tertiary Amines………….....23 1.2.2.4 Biochemical Deamination Reactions………………...…….…..25 CHAPTER 2: PART 1: Transition Metal Catalyzed C-O Bond Activation Reactions .... 31 2.1 Transition Metal Catalyzed Hydrogenolysis of Carbonyl Compounds. ......... 31 2.1.1 Classical Carbonyl Reduction Methods ................................................... 31 2.1.2 Wolff–Kishner Reduction..................................................................... 31 2.1.2.1 Catalytic Modification to Wolff-Kishner Reduction…………....32 2.1.3 Clemmensen Reduction ........................................................................ 33 2.1.4 Reduction of ketone/aldehydes using aluminum, silane etc. ................ 35 2.1.5 Homogeneous Catalytic Reduction Methods ....................................... 36 2.1.6 Reductive Deoxygenation of Ester, Amide, and other Carbonyl Compounds …………………………………………………………………38 2.1.7 Hydrogenolysis of C-O Bonds ................................................................. 43 2.1.7.1 Hydrogenolysis of Aryl Ethers .......................................................... 43 CHAPTER 2: PART 2: Transition Metal Catalyzed Ether Synthesis .............................. 53 2.2.1 Introduction .............................................................................................. 53 2.2.2 Classical Methods .................................................................................... 54 2.2.2.1 O-Alkylation.......................................................................................... 54 2.2.2.2 Mitsunobu Etherification ................................................................... 54 2.2.2.3 Etherification by Using DialkylPhosphites ....................................... 55 2.2.3 Cross-coupling Reactions ......................................................................... 57 2.2.3.1 Ullman Reaction ................................................................................ 57 2.2.4 Catalytic Etherification Methods ............................................................. 60 2.2.5 Etherification by [IrCl 2Cp*(NHC)] Catalyst ............................................ 63 2.2.6 dehydrative Etherification of Alcohols ...................................................
Load more

Recommended publications
  • Modern-Reduction-Methods.Pdf
    Modern Reduction Methods Edited by Pher G. Andersson and Ian J. Munslow Related Titles Yamamoto, H., Ishihara, K. (eds.) Torii, S. Acid Catalysis in Modern Electroorganic Reduction Organic Synthesis Synthesis 2008 2006 ISBN: 978-3-527-31724-0 ISBN: 978-3-527-31539-0 Roberts, S. M. de Meijere, A., Diederich, F. (eds.) Catalysts for Fine Chemical Metal-Catalyzed Cross- Synthesis V 5 – Regio and Coupling Reactions Stereo-Controlled Oxidations 2004 and Reductions ISBN: 978-3-527-30518-6 2007 Online Book Wiley Interscience Bäckvall, J.-E. (ed.) ISBN: 978-0-470-09024-4 Modern Oxidation Methods 2004 de Vries, J. G., Elsevier, C. J. (eds.) ISBN: 978-3-527-30642-8 The Handbook of Homogeneous Hydrogenation 2007 ISBN: 978-3-527-31161-3 Modern Reduction Methods Edited by Pher G. Andersson and Ian J. Munslow The Editors All books published by Wiley-VCH are carefully produced. Nevertheless, authors, editors, and Prof. Dr. Pher G. Andersson publisher do not warrant the information Uppsala University contained in these books, including this book, to Department of Organic Chemistry be free of errors. Readers are advised to keep in Husargatan 3 mind that statements, data, illustrations, 751 23 Uppsala procedural details or other items may Sweden inadvertently be inaccurate. Dr. Ian J. Munslow Library of Congress Card No.: Uppsala University applied for Department of Biochemistry and Organic Chemistry Husargatan 3 British Library Cataloguing-in-Publication Data 751 23 Uppsala A catalogue record for this book is available from Sweden the British Library. Bibliographic information published by the Deutsche Nationalbibliothek Die Deutsche Nationalbibliothek lists this publication in the Deutsche Nationalbibliografi e; detailed bibliographic data are available on the Internet at <http://dnb.d-nb.de>.
    [Show full text]
  • Lanthanide Replacement in Organic Synthesis: Calcium-Mediated Luche-Type Reduction of Α,Β-Functionalised Ketones
    Lanthanide Replacement in Organic Synthesis: Calcium-mediated Luche-type Reduction of α,β-functionalised Ketones A thesis submitted by Nina Viktoria Forkel In partial fulfilment of the requirement for a degree of Doctor of Philosophy Imperial College London Department of Chemistry South Kensington Campus SW7 2AZ London United Kingdom September 2013 Lanthanide Replacement in Organic Synthesis: Calcium-mediated Luche-type Reduction of α,β-functionalised Ketones “Man kann sich die Weite und Möglichkeiten des Lebens gar nicht unerschöpflich genug denken.” (Rainer Maria Rilke) This thesis is dedicated to all my loved ones. Declaration of originality and statement of copyright Declaration of originality I, Nina V. Forkel, certify that the research described within this thesis was carried out in the Department of Chemistry at Imperial College London between October 2009 and September 2012. It was accomplished under the primary supervision of Dr Matthew J. Fuchter, Imperial College London, along with supervision from Dr David A. Henderson, Pfizer Ltd. The entire body of work is that of the author, unless otherwise stated to the contrary, and has not been submitted previously for a degree at this or any other university. Statement of copyright The copyright of this thesis rests with the author and is made available under a Creative Commons Attribution Non-Commercial No Derivatives licence. Researchers are free to copy, distribute or transmit the thesis on the condition that they attribute it, that they do not use it for commercial purposes, and that they do not alter, transform or build upon it. For any reuse or redistribution, researchers must make clear to others the licence terms of this work.
    [Show full text]
  • Development of a Quantitative PCR Assay for the Detection And
    bioRxiv preprint doi: https://doi.org/10.1101/544247; this version posted February 8, 2019. The copyright holder for this preprint (which was not certified by peer review) is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under aCC-BY-NC-ND 4.0 International license. Development of a quantitative PCR assay for the detection and enumeration of a potentially ciguatoxin-producing dinoflagellate, Gambierdiscus lapillus (Gonyaulacales, Dinophyceae). Key words:Ciguatera fish poisoning, Gambierdiscus lapillus, Quantitative PCR assay, Great Barrier Reef Kretzschmar, A.L.1,2, Verma, A.1, Kohli, G.S.1,3, Murray, S.A.1 1Climate Change Cluster (C3), University of Technology Sydney, Ultimo, 2007 NSW, Australia 2ithree institute (i3), University of Technology Sydney, Ultimo, 2007 NSW, Australia, [email protected] 3Alfred Wegener-Institut Helmholtz-Zentrum fr Polar- und Meeresforschung, Am Handelshafen 12, 27570, Bremerhaven, Germany Abstract Ciguatera fish poisoning is an illness contracted through the ingestion of seafood containing ciguatoxins. It is prevalent in tropical regions worldwide, including in Australia. Ciguatoxins are produced by some species of Gambierdiscus. Therefore, screening of Gambierdiscus species identification through quantitative PCR (qPCR), along with the determination of species toxicity, can be useful in monitoring potential ciguatera risk in these regions. In Australia, the identity, distribution and abundance of ciguatoxin producing Gambierdiscus spp. is largely unknown. In this study we developed a rapid qPCR assay to quantify the presence and abundance of Gambierdiscus lapillus, a likely ciguatoxic species. We assessed the specificity and efficiency of the qPCR assay. The assay was tested on 25 environmental samples from the Heron Island reef in the southern Great Barrier Reef, a ciguatera endemic region, in triplicate to determine the presence and patchiness of these species across samples from Chnoospora sp., Padina sp.
    [Show full text]
  • Treatment Protocol Copyright © 2018 Kostoff Et Al
    Prevention and reversal of Alzheimer's disease: treatment protocol Copyright © 2018 Kostoff et al PREVENTION AND REVERSAL OF ALZHEIMER'S DISEASE: TREATMENT PROTOCOL by Ronald N. Kostoffa, Alan L. Porterb, Henry. A. Buchtelc (a) Research Affiliate, School of Public Policy, Georgia Institute of Technology, USA (b) Professor Emeritus, School of Public Policy, Georgia Institute of Technology, USA (c) Associate Professor, Department of Psychiatry, University of Michigan, USA KEYWORDS Alzheimer's Disease; Dementia; Text Mining; Literature-Based Discovery; Information Technology; Treatments Prevention and reversal of Alzheimer's disease: treatment protocol Copyright © 2018 Kostoff et al CITATION TO MONOGRAPH Kostoff RN, Porter AL, Buchtel HA. Prevention and reversal of Alzheimer's disease: treatment protocol. Georgia Institute of Technology. 2018. PDF. https://smartech.gatech.edu/handle/1853/59311 COPYRIGHT AND CREATIVE COMMONS LICENSE COPYRIGHT Copyright © 2018 by Ronald N. Kostoff, Alan L. Porter, Henry A. Buchtel Printed in the United States of America; First Printing, 2018 CREATIVE COMMONS LICENSE This work can be copied and redistributed in any medium or format provided that credit is given to the original author. For more details on the CC BY license, see: http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License<http://creativecommons.org/licenses/by/4.0/>. DISCLAIMERS The views in this monograph are solely those of the authors, and do not represent the views of the Georgia Institute of Technology or the University of Michigan. This monograph is not intended as a substitute for the medical advice of physicians. The reader should regularly consult a physician in matters relating to his/her health and particularly with respect to any symptoms that may require diagnosis or medical attention.
    [Show full text]
  • 1 Gambierol 1 2 3 4 Makoto Sasaki, Eva Cagide, and 5 M
    34570 FM i-xviii.qxd 2/9/07 9:16 AM Page i PHYCOTOXINS Chemistry and Biochemistry 34570 FM i-xviii.qxd 2/9/07 9:16 AM Page iii PHYCOTOXINS Chemistry and Biochemistry Luis M. Botana Editor 34570 FM i-xviii.qxd 2/9/07 9:16 AM Page iv 1 2 3 Dr. Luis M. Botana is professor of Pharmacology, University of Santiago de Compostela, Spain. His group is a 4 world leader in the development of new methods to monitor the presence of phycotoxins, having developed 5 methods to date for saxitoxins, yessotoxin, pectenotoxin, ciguatoxins, brevetoxins, okadaic acid and dinophy- 6 sistoxins. Dr. Botana is the editor of Seafood and Freshwater Toxins: Pharmacology, Physiology and Detection, 7 to date the only comprehensive reference book entirely devoted to marine toxins. 8 ©2007 Blackwell Publishing 9 All rights reserved 10 1 Blackwell Publishing Professional 2 2121 State Avenue, Ames, Iowa 50014, USA 3 4 Orders: 1-800-862-6657 5 Office: 1-515-292-0140 6 Fax: 1-515-292-3348 7 Web site: www.blackwellprofessional.com 8 Blackwell Publishing Ltd 9 9600 Garsington Road, Oxford OX4 2DQ, UK 20 Tel.: +44 (0)1865 776868 1 2 Blackwell Publishing Asia 3 550 Swanston Street, Carlton, Victoria 3053, Australia 4 Tel.: +61 (0)3 8359 1011 5 6 Authorization to photocopy items for internal or personal use, or the internal or personal use of specific clients, 7 is granted by Blackwell Publishing, provided that the base fee is paid directly to the Copyright Clearance Cen- 8 ter, 222 Rosewood Drive, Danvers, MA 01923.
    [Show full text]
  • A A–803467, 98 Absorption, Distribution, Metabolism, Elimination
    Index A Anxiety disorders, 55 A–803467, 98 APD. See Action potential duration Absorption, distribution, metabolism, Arrhythmias, 45, 46 elimination and toxicity Aryl sulfonamido indanes, 126–128, 130 (ADMET), 193 ATP-sensitive potassium channels (KATP Absorption, distribution, metabolism, channels), 61 excretion, and toxicity Atrial effective refractory period (AERP), 122, (ADMET), 68 124–126, 128, 129, 132, 138 Acetylcholine binding protein (AChBP), Autoimmune diseases, 254 61, 62, 64 AZD7009, 101 Acetylcholine receptor (AChR), 57, 64 Azimilide, 139 Action potential duration (APD), 120, 122, 123, 128, 132 B Action potentials, 243, 256, 259 Basis set, 69–70 ADME/T, 299, 304 b-Barrel membrane proteins AERP. See Atrial effective refractory period genome-wide annotation, 13 Agitoxin (AgTX), 60 machine-learning techniques Agonists, 59–61, 64 residue pair preference, 11 Alinidine, 40–42 TMBs, 10 ALS. See Amyotrophic lateral sclerosis pipeline, genomic sequences, 14 Alzheimer, 55, 61 statistical method, 9–10 AMBER, 61, 65 Bending hinge, 64 2-Amino–2-imidazolidinone, 123, 125 Benzanilide, 256–257 Ammi visnaga, 254 Benzimidazolone, 256–257 b-Amyloid peptide (Ab), 62–63, 65 Benzocaine, 140 Amyotrophic lateral sclerosis (ALS), 90, 94, Benzodiazepines, 245 101 Benzopyrane, 127–128 Anionic channel blockers Benzopyrans, 61, 246–251, 261 mechanism of action of, 329–330 Benzothiadiazine 1,1-dioxide, 252–254 Antagonists, 59, 60 Benzothiadiazines, 253 Antiarrhythmic, 65–66, 68, 99, 101 Benzothiazepine, 70 Antiarrhythmic agents Benzothiazine derivatives, 251–252 class I, 245 Benzotriazole, 256–257 class II, 245 Bestrophins, 321, 322, 330, 331 class III, 245 Big potassium channels (BK channels), Antidepressant, 65–67 256, 257 Antiepileptic, 46 Bupivacaine, 56, 58, 59, 64, 69, 140 S.P.
    [Show full text]
  • Metabolic Carbonyl Reduction of Anthracyclines — Role in Cardiotoxicity and Cancer Resistance
    Invest New Drugs DOI 10.1007/s10637-017-0443-2 REVIEW Metabolic carbonyl reduction of anthracyclines — role in cardiotoxicity and cancer resistance. Reducing enzymes as putative targets for novel cardioprotective and chemosensitizing agents Kamil Piska1 & Paulina Koczurkiewicz1 & Adam Bucki 2 & Katarzyna Wójcik-Pszczoła1 & Marcin Kołaczkowski2 & Elżbieta Pękala1 Received: 23 November 2016 /Accepted: 17 February 2017 # The Author(s) 2017. This article is published with open access at Springerlink.com Summary Anthracycline antibiotics (ANT), such as doxoru- monoHER, curcumin, (−)-epigallocatechin gallate, resvera- bicin or daunorubicin, are a class of anticancer drugs that are trol, berberine or pixantrone, and their modulating effect on widely used in oncology. Although highly effective in cancer the activity of ANT is characterized and discussed as potential therapy, their usefulness is greatly limited by their mechanism of action for novel therapeutics in cancer cardiotoxicity. Possible mechanisms of ANT cardiotoxicity treatment. include their conversion to secondary alcohol metabolites (i.e. doxorubicinol, daunorubicinol) catalyzed by carbonyl re- Keywords Anthracyclines . Cardiotoxicity . Resistance . ductases (CBR) and aldo-keto reductases (AKR). These me- Pharmacokinetics . Drug metabolism . Anticancer agents tabolites are suspected to be more cardiotoxic than their parent compounds. Moreover, overexpression of ANT-reducing en- zymes (CBR and AKR) are found in many ANT-resistant Introduction cancers. The secondary metabolites show decreased cytotoxic properties and are more susceptible to ABC-mediated efflux Anthracyclines (ANT) are a class of cell-cycle non-specific than their parent compounds; thus, metabolite formation is anticancer antibiotics that were first isolated from the considered one of the mechanisms of cancer resistance. Streptomyces genus in the early 1960s.
    [Show full text]
  • Marine Natural Products and Their Potential Application in the Future
    AJSTD Vol. 22 Issue 4 pp. 297-311 (2005) MARINE NATURAL PRODUCTS AND THEIR POTENTIAL APPLICATION IN THE FUTURE Chau Van Minh*, Phan Van Kiem, and Nguyen Hai Dang Institute of Natural Products Chemistry, Vietnamese Academy of Science and Technology 18 Hoang Quoc Viet Road, Cau Giay, Hanoi, Vietnam Received 04 November 2005 1. INTRODUCTION Oceans are the diverse resource, which cover more than 70% of the earth’s surface. No doubt, with 34 of 36 phyla of life represented, oceans are the greatest biodiversity in the world [1]. They are the extraordinary natural source of microorganism, algae, sponge, coelenterate, bryozoan, mollusk, and echinoderm… Especially, on coral reef, where shelter more than 1000 species per m2. Surprisingly, there is only a small number of researches in this field. Therefore increasing research on marine natural source may provide good results for exploiting and developing valuable natural products which benefit for human. Marine environment is a rich source of biological and chemical diversity. The diversity has been unique source of chemical compounds of potential for pharmaceuticals, cosmetics, dietary supplements, and agrochemicals. Ecological pressure, including competitions for food and space, the fouling of predator and surface, has led to the evolution of secondary metabolites with various biological activities. Many organisms are soft bodies and/or unmoved, hardly survive with the threat from around environment. Hence they have evolved the ability to synthesize toxic compounds or obtain them from microorganism to defense against predator or to paralyze their prey. The questions such as, why do fish not eat particular algae? Why do two sponges grow and expand until they reach but not grow over each other? may be explained by these reasons.
    [Show full text]
  • Feni Nanoparticles with Carbon Armor As Sustainable Hydrogenation Catalysts: Towards Cite This: J
    Journal of Materials Chemistry A View Article Online COMMUNICATION View Journal | View Issue FeNi nanoparticles with carbon armor as sustainable hydrogenation catalysts: towards Cite this: J. Mater. Chem. A,2014,2, 11591 biorefineries† Received 15th May 2014 Gianpaolo Chieffi, Cristina Giordano, Markus Antonietti and Davide Esposito* Accepted 28th May 2014 DOI: 10.1039/c4ta02457e www.rsc.org/MaterialsA Carbon supported FeNi nanoparticles were prepared by carbothermal and electronic properties of the active sites. Moreover, catalyst reduction of cellulose filter paper impregnated with Fe and Ni salts. stability is improved by inhibiting the sintering or the leaching The resulting carbon enwrapped alloy nanoparticles were employed of the active species through interaction with the second metal. as an efficient catalyst for the continuous hydrogenation of molecules The development of new sustainable hydrogenation catalysts Creative Commons Attribution 3.0 Unported Licence. obtainable from different fractions of lignocellulosic biomass. Scale- with superior stability is also highly desired for the successful up and time on stream tests over 80 hours proved the catalyst stable development of bioreneries for the conversion of raw ligno- and durable of over a wide range of conditions. cellulosic materials into chemicals and fuels, where poor selectivity and catalyst deactivation are sensibly affected by the high heterogeneity of biomass. In the present work we describe the sustainable synthesis of Introduction a carbonized lter paper (CFP) supported bimetallic FeNi alloy catalyst and investigate its activity during the continuous Catalytic hydrogenation has been one of the most studied hydrogenation of different functional groups and model This article is licensed under a reactions for decades.
    [Show full text]
  • Thermodynamic Constraints Shape the Structure of Carbon Fixation Pathways
    Biochimica et Biophysica Acta 1817 (2012) 1646–1659 Contents lists available at SciVerse ScienceDirect Biochimica et Biophysica Acta journal homepage: www.elsevier.com/locate/bbabio Thermodynamic constraints shape the structure of carbon fixation pathways Arren Bar-Even, Avi Flamholz, Elad Noor, Ron Milo ⁎ Department of Plant Sciences, The Weizmann Institute of Science, Rehovot 76100, Israel article info abstract Article history: Thermodynamics impose a major constraint on the structure of metabolic pathways. Here, we use carbon fixa- Received 27 March 2012 tion pathways to demonstrate how thermodynamics shape the structure of pathways and determine the cellular Received in revised form 7 May 2012 resources they consume. We analyze the energetic profile of prototypical reactions and show that each reaction Accepted 9 May 2012 type displays a characteristic change in Gibbs energy. Specifically, although carbon fixation pathways display a Available online 17 May 2012 considerable structural variability, they are all energetically constrained by two types of reactions: carboxylation and carboxyl reduction. In fact, all adenosine triphosphate (ATP) molecules consumed by carbon fixation path- Keywords: – – Reduction potential ways with a single exception are used, directly or indirectly, to power one of these unfavorable reactions. Carbon fixation When an indirect coupling is employed, the energy released by ATP hydrolysis is used to establish another chem- Thermodynamic favorability ical bond with high energy of hydrolysis, e.g. a thioester. This bond is cleaved by a downstream enzyme to ener- Exergonism gize an unfavorable reaction. Notably, many pathways exhibit reduced ATP requirement as they couple Reaction coupling unfavorable carboxylation or carboxyl reduction reactions to exergonic reactions other than ATP hydrolysis.
    [Show full text]
  • 7-1 EXPERIMENT 7: Reduction of Carbonyl Compounds – Achiral And
    Chemistry 2283g Experiment 7 – Carbonyl Reduction EXPERIMENT 7: Reduction of Carbonyl Compounds – Achiral and Chiral Reduction Relevant Sections in the text (Wade, 7th ed.) • 10.11 (p. 449) Reduction of the carbonyl group: synthesis of 1° and 2° alcohols • 18.12 (p. 831) Reactions of ketones and aldehydes: nucleophilic addition • 21.8 (p. 1013) Reduction of acid derivatives A portion of this experiment is based on a paper in J. Chem. Ed. by N. Pohl, A. Clague and K. Schwarz Department of Chemistry, Iowa State University, Ames IA General Concepts A reduction is often defined as the gain of two hydrogen atoms or the loss of an oxygen atom, or both. This leads to a very important conversion reaction, where aldehydes and ketones are reduced to primary and secondary alcohols. O [H] OH R1 R2 R1 R2 H Although various methods for this conversion are possible, the most frequently employed is the use of complex metal hydride reagents such as lithium aluminum hydride (LiAlH4) and sodium borohydride (NaBH4). These particular reagents are also soluble in organic solvents and are not as reactive as a strong base, which is not true for other metal hydrides such as LiH, NaH and KH. Of the two most common reducing reagents, LiAlH4 is the more powerful, reducing most carbonyl containing compounds including aldehydes, ketones, esters, and amides. A more selective reducing agent is NaBH4, which only reacts with aldehydes and ketones due to its milder nature. Both reducing agents are a source of H−, which is transferred from the boron or aluminum to the carbonyl group.
    [Show full text]
  • Influence of Lipid-Soluble Gating Modifier Toxins on Sodium Influx in Neocortical Neurons
    0022-3565/08/3262-604–613$20.00 THE JOURNAL OF PHARMACOLOGY AND EXPERIMENTAL THERAPEUTICS Vol. 326, No. 2 Copyright © 2008 by The American Society for Pharmacology and Experimental Therapeutics 138230/3358916 JPET 326:604–613, 2008 Printed in U.S.A. Influence of Lipid-Soluble Gating Modifier Toxins on Sodium Influx in Neocortical Neurons Zhengyu Cao, Joju George, William H. Gerwick, Daniel G. Baden, Jon D. Rainier, and Thomas F. Murray Creighton University, School of Medicine, Department of Pharmacology, Omaha, Nebraska (Z.C., J.G., T.F.M.); Center for Marine Biotechnology and Biomedicine, Scripps Institution of Oceanography, University of California at San Diego, La Jolla, California (W.H.G.); University of North Carolina, Center for Marine Science Research, Wilmington, North Carolina (D.G.B.); and Department of Chemistry, University of Utah, Salt Lake City, Utah (J.D.R.) Received February 20, 2008; accepted April 25, 2008 Downloaded from ABSTRACT The electrical signals of neurons are fundamentally dependent tridine and aconitine, and the pyrethroid deltamethrin were ϩ on voltage-gated sodium channels (VGSCs), which are respon- somewhat lower with maximal [Na ]i increments of less than 40 sible for the rising phase of the action potential. An array of mM. The rank order of efficacy of sodium channel gating mod- jpet.aspetjournals.org naturally occurring and synthetic neurotoxins have been iden- ifiers was brevetoxin (PbTx)-1 Ͼ PbTx-desoxydioxolane Ͼ tified that modify the gating properties of VGSCs. Using murine batrachotoxin Ͼ antillatoxin Ͼ PbTx-2 ϭ PbTx-3 Ͼ PbTx- neocortical neurons in primary culture, we have compared the 3␣-naphthoate Ͼ veratridine Ͼ deltamethrin Ͼ aconitine Ͼ ability of VGSC gating modifiers to evoke Naϩ influx.
    [Show full text]