Manipulating Selectivity and Reactivity in Palladium-Catalyzed Oxidation Reactions
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Olefin-Metathesis Catalysts for the Preparation of Molecules and Materials (Nobel Lecture 2005)**
NOBEL LECTURES DOI: 10.1002/adsc.200600523 Olefin-Metathesis Catalysts for the Preparation of Molecules and Materials (Nobel Lecture 2005)** Robert H. Grubbsa,* a Victor and Elizabeth Atkins Professor of Chemistry Arnold and Mabel Beckman Laboratories of Chemical Synthesis California Institute of Technology, Pasadena, CA 91125, USA Fax : (+1)-626–564–9297 [**] Copyright The Nobel Foundation 2005. We thank the Nobel Foundation, Stockholm, for permission to print this lecture Received: February 21, 2006 This is a story of our exploration of the olefin-meta- ly added to this reaction, 1-butene was again ob- thesis reaction, a reaction that has been the major served. This discovery has since served as the founda- emphasis of my independent research. As with all sto- tion for an amazing array of nickel chemistry and cat- ries of scientific discovery, there are three compo- alysis. In addition, as nickel had been found to possess nents: the discoveries, the resulting applications, and, unexpected reactivity, other metal salts were also in- perhaps the most important of all, the people in- vestigated. In particular, when titanium and zirconium volved. Starting from observations made from seem- halides were used in combination with alkyl alumi- ingly unrelated work, our investigations into the fun- num compounds, a new form of polyethylene was ob- damental chemistry of this transformation have been tained. Natta further demonstrated that similar cata- an exciting journey, with major advances often result- lysts could promote the formation of stereoregular ing from complete surprises, mistakes, and simple in- polymers from propylene. The 1963 Nobel Prize in tuition. Ultimately, these efforts have contributed to Chemistry was awarded to Ziegler and Natta for this olefin metathesis becoming the indispensable synthet- work. -
Part I: Carbonyl-Olefin Metathesis of Norbornene
Part I: Carbonyl-Olefin Metathesis of Norbornene Part II: Cyclopropenimine-Catalyzed Asymmetric Michael Reactions Zara Maxine Seibel Submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy in the Graduate School of Arts and Sciences COLUMBIA UNIVERSITY 2016 1 © 2016 Zara Maxine Seibel All Rights Reserved 2 ABSTRACT Part I: Carbonyl-Olefin Metathesis of Norbornene Part II: Cyclopropenimine-Catalyzed Asymmetric Michael Reactions Zara Maxine Seibel This thesis details progress towards the development of an organocatalytic carbonyl- olefin metathesis of norbornene. This transformation has not previously been done catalytically and has not been done in practical manner with stepwise or stoichiometric processes. Building on the previous work of the Lambert lab on the metathesis of cyclopropene and an aldehyde using a hydrazine catalyst, this work discusses efforts to expand to the less stained norbornene. Computational and experimental studies on the catalytic cycle are discussed, including detailed experimental work on how various factors affect the difficult cycloreversion step. The second portion of this thesis details the use of chiral cyclopropenimine bases as catalysts for asymmetric Michael reactions. The Lambert lab has previously developed chiral cyclopropenimine bases for glycine imine nucleophiles. The scope of these catalysts was expanded to include glycine imine derivatives in which the nitrogen atom was replaced with a carbon atom, and to include imines derived from other amino acids. i Table of Contents List of Abbreviations…………………………………………………………………………..iv Part I: Carbonyl-Olefin Metathesis…………………………………………………………… 1 Chapter 1 – Metathesis Reactions of Double Bonds………………………………………….. 1 Introduction………………………………………………………………………………. 1 Olefin Metathesis………………………………………………………………………… 2 Wittig Reaction…………………………………………………………………………... 6 Tebbe Olefination………………………………………………………………………... 9 Carbonyl-Olefin Metathesis……………………………………………………………. -
Organoboranes in Organic Syntheses Including Suzuki Coupling Reaction
HETEROCYCLES, Vol. 80, No. 1, 2010 15 HETEROCYCLES, Vol. 80, No. 1, 2010, pp. 15 - 43. © The Japan Institute of Heterocyclic Chemistry DOI: 10.3987/COM-09-S(S)Summary ORGANOBORANES IN ORGANIC SYNTHESES INCLUDING SUZUKI COUPLING REACTION Akira Suzuki In 1962 I had a lively interest in Wacker reaction [the oxidation of ethylene to acetaldehyde in the presence of palladium chloride and cupric chloride (Angew. Chem. 1959, 71, 176)] and began a literature survey. One Saturday afternoon during that time, I went a bookstore in Sapporo to look at new chemistry books and found a red and black two-tone colored book on the shelf that did not look like a chemistry book. The book was "Hydroboration" written by Professor Herbert C. Brown of Purdue University. It seemed to be an interesting book, so, I bought it. This book changed the course of my career, and my fascination with the chemistry of hydroboration reaction and organoboron compounds thus prepared by hydroboration began after reading the book. I immediately wrote to Professor Brown requesting to work as a postdoctoral research fellow. At that time Professor Brown was at Heidelberg in Germany as a visiting professor. He kindly wrote me a letter of acceptance, and I began a study of the stereochemistry of hydroboration reaction at Purdue (1963-65). Through this work I came to understand hydroboration and the interesting characteristics of organoboranes. My family (wife and two small girls) and I had a very good time there and made good friends. Of course I enjoyed chemistry. After a stay of about two years at Purdue, I returned to Japan with my family at the end of March 1965. -
Syntheses and Eliminations of Cyclopentyl Derivatives David John Rausch Iowa State University
Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1966 Syntheses and eliminations of cyclopentyl derivatives David John Rausch Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Organic Chemistry Commons Recommended Citation Rausch, David John, "Syntheses and eliminations of cyclopentyl derivatives " (1966). Retrospective Theses and Dissertations. 2875. https://lib.dr.iastate.edu/rtd/2875 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Retrospective Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. This dissertation has been microfilmed exactly as received 66—6996 RAUSCH, David John, 1940- SYNTHESES AND ELIMINATIONS OF CYCLOPENTYL DERIVATIVES. Iowa State University of Science and Technology Ph.D., 1966 Chemistry, organic University Microfilms, Inc., Ann Arbor, Michigan SYNTHESES AND ELIMINATIONS OF CYCLOPENTYL DERIVATIVES by David John Rausch A Dissertation Submitted to the Graduate Faculty in Partial Fulfillment of The Requirements for the Degree of DOCTOR OF PHILOSOPHY Major Subject: Organic Chemistry Approved : Signature was redacted for privacy. Signature was redacted for privacy. Head of Major Department Signature was redacted for privacy. Iowa State University Of Science and Technology Ames, Iowa 1966 ii TABLE OF CONTENTS VITA INTRODUCTION HISTORICAL Conformation of Cyclopentanes Elimination Reactions RESULTS AND DISCUSSION Synthetic Elimination Reactions EXPERIMENTAL Preparation and Purification of Materials Procedures and Data for Beta Elimination Reactions SUMMARY LITERATURE CITED ACKNOWLEDGEMENTS iii VITA The author was born in Aurora, Illinois, on October 24, 1940, to Mr. -
Chemistry 301-301A - Hour Examination #3, December 11, 2003
Chemistry 301-301A - Hour Examination #3, December 11, 2003 “.....as we know, there are known unknowns; there are things we know we know. We also know there are known unknowns; that is to say we know there are some things we do not know. But there are also unknown unknowns - the ones we don't know we don't know.” Donald Rumsfeld (winner of a British award given to the worst mangler of the English language in 2003) “I know, a proof is a proof. What kind of a proof is a proof? A proof is a proof and when you have a good proof it's because it's proven." Jean Chrétien (hon. mention for the same award) 1[18 points] (a) Acid-catalyzed addition of water to 3-methyl-1-butene (1) results in formation of large amounts of a rearranged alcohol (2), in addition to the expected alcohol (3). Explain, with excellent arrow formalisms. H2O + H O+ 3 OH OH 1 3 2 (b) On the other hand hydroboration of 1, followed by oxidation, does not lead to any rearranged product. Only alcohol 4 is formed. Explain. Detailed mechanisms are not needed here, but a drawing of the transition state for the hydroboration step is. 1. BH3 OH 2. HOOH/HO – 1 4 (c) But there are some strange things that happen in hydroboration. For example when 2-methyl-2-butene (5) is hydroborated at high temperature, then treated with HOOH/HO–, alcohol 4 is still one of the products. Explain mechanistcally. Hint: at high temperature hydroboration is reversible. -
Wacker Oxidation ~Anti-Markovnikov~
Anti-Markovnikov Olefin Functionalization ~Prof. Robert H. Grubbs’ Work~ 4th Literature Seminar July 5, 2014 Soichi Ito (D1) Contents 1. Introduction • Flow of Prof. Grubbs’ Research • Markovnikov’s Rule • Wacker Oxidation 2. Grubbs’ Work • Substrate-Controlled Wacker Oxidation • Catalyst-Controlled Wacker-Type Oxidation 2 Introduction ~Flow of Research~ Olefin Metathesis Anti-Markovnikov Wacker Oxidation of Terminal Olefin Substrate-Controlled Wacker Oxidation of Internal Olefin Z-Selective Metathesis Hydration Ethenolysis + Reduction Hydroamination Z-Selective Ethenolysis Catalyst-Controlled Decarbonylative Dehydration Hydrophosphonation Production of Terminal Olefin Functionalization of Terminal Olefin 3 Introduction ~Markovnikov’s Rule~ Two-Step Two-Step (+1C) 4 Robert H. Grubbs et al. Science, 2011, 333, 1609. Anti-Markovnikov Hydration of Olefins • One-Step William C. Trogler et al. Science 1986, 233, 1069. This work was difficult to reproduce. Inorg. Chem. 1988, 27, 3151. • One-Step with Activated Olefins Robert G. Bergman and F. Dean Toste et al. J. Am. Chem. Soc. 2003, 125, 8696. Ben L. Feringa and Gerard Roelfes et al. Nat. Chem. 2010, 2, 991. • Three-Step 5 Shannon S. Stahl et al. J. Am. Chem. Soc. 2010, 132, 15116. Anti-Markovnikov Wacker Oxidation / Reduction Strategy Oxidation cycle must be compatible with the reduction cycle. aldehyde-selective Wacker Oxidation 6 Robert H. Grubbs et al. Science, 2011, 333, 1609. Introduction ~Wacker-Tsuji Oxidation~ • 1894 F. C. Phillips reported stoichiometric reaction. • 1959 J. Smidt et al. reported the Wacker process. (oxidation of ethylene to acetaldehyde) Investigations for convenient laboratory methods • 1976 J. Tsuji et al. reported PdCl2, CuCl / DMF, H2O method. “Terminal alkenes may be viewed as masked ketones.” 7 Jacques Muzart Tetrahedron 2007, 63, 7505. -
Self-Metathesis of 1-Octene Using Alumina-Supported Re2o7 in Supercritical CO2
Top Catal DOI 10.1007/s11244-008-9154-4 ORIGINAL PAPER Self-Metathesis of 1-Octene Using Alumina-Supported Re2O7 in Supercritical CO2 Massimo Fabris Æ Cindy Aquino Æ Antony J. Ward Æ Alvise Perosa Æ Thomas Maschmeyer Æ Maurizio Selva Ó Springer Science+Business Media, LLC 2009 Abstract In this contribution we describe the use of basic science has been applied for the benefit of man, heterogeneous catalysts for the liquid-phase self-metathesis society and the environment’’.1 Their contribution was of 1-octene in supercritical CO2. Our work aims at recognized for understanding the mechanism, and for addressing the mass-transfer problems associated with such developing very efficient and selective discrete metal- reaction systems. By coupling a heterogeneous supported based catalysts. Re2O7 catalyst with the use of scCO2, the self-metathesis Nonetheless, one should not forget that the metathesis of 1-octene takes place by and large much more rapidly reaction using heterogeneous catalysis has been an estab- than in traditional solvent media, and furthermore, by using lished industrial process since 1966, based on the use of scCO2 the overall efficiency and sustainability of the supported (usually on silica and alumina) metal oxides transformation can be improved. such as tungsten, nickel, cobalt, rhenium, and molybde- num. Three significant examples come to mind and are Keywords Metathesis Á 1-Octene Á Supercritical CO2 Á here recalled briefly. [1]. Re/Al O 2 3 1. The historic Phillips triolefin process for the produc- tion of ethene and 2-butene from propene using a WO /SiO catalyst, [2] that was shut down in 1972 1 Introduction 3 2 after 6 years of operation due to increased demand for propene, and later reutilized in the reverse direction to The metathesis of olefins is a very elegant and widely produce propene. -
Reactions of Alkenes and Alkynes
05 Reactions of Alkenes and Alkynes Polyethylene is the most widely used plastic, making up items such as packing foam, plastic bottles, and plastic utensils (top: © Jon Larson/iStockphoto; middle: GNL Media/Digital Vision/Getty Images, Inc.; bottom: © Lakhesis/iStockphoto). Inset: A model of ethylene. KEY QUESTIONS 5.1 What Are the Characteristic Reactions of Alkenes? 5.8 How Can Alkynes Be Reduced to Alkenes and 5.2 What Is a Reaction Mechanism? Alkanes? 5.3 What Are the Mechanisms of Electrophilic Additions HOW TO to Alkenes? 5.1 How to Draw Mechanisms 5.4 What Are Carbocation Rearrangements? 5.5 What Is Hydroboration–Oxidation of an Alkene? CHEMICAL CONNECTIONS 5.6 How Can an Alkene Be Reduced to an Alkane? 5A Catalytic Cracking and the Importance of Alkenes 5.7 How Can an Acetylide Anion Be Used to Create a New Carbon–Carbon Bond? IN THIS CHAPTER, we begin our systematic study of organic reactions and their mecha- nisms. Reaction mechanisms are step-by-step descriptions of how reactions proceed and are one of the most important unifying concepts in organic chemistry. We use the reactions of alkenes as the vehicle to introduce this concept. 129 130 CHAPTER 5 Reactions of Alkenes and Alkynes 5.1 What Are the Characteristic Reactions of Alkenes? The most characteristic reaction of alkenes is addition to the carbon–carbon double bond in such a way that the pi bond is broken and, in its place, sigma bonds are formed to two new atoms or groups of atoms. Several examples of reactions at the carbon–carbon double bond are shown in Table 5.1, along with the descriptive name(s) associated with each. -
New Reactions of Cyclic Oxygen, Nitrogen and Sulfur Acetal Derivatives
New Reactions of Cyclic Oxygen, Nitrogen and Sulfur Acetal Derivatives Samuel Edward Mann Supervisor Dr. Tom Sheppard A thesis submitted to University College London in partial fulfilment of the requirements for the degree of Doctor of Philosophy Declaration I, Samuel Edward Mann confirm that the work presented in this thesis is my own. Where information has been derived from other sources, I confirm that this has been indicated in the thesis. ………………………… i Abstract Abstract This thesis describes the development of new reactions of cyclic oxygen, nitrogen and sulfur acetal derivatives and their applications in a diverse range of synthetic organic and organometallic chemistry. Detailed herein are advances in three main areas of acetal chemistry, namely: studies towards a new methodology for the synthesis of medium ring heterocycles; the use of thioacetals as directing groups for the palladium-mediated oxidation of olefins; and multi-component reactions for the synthesis of drug-like heterocyclic compounds. A brief overview of the chemistry of cyclic acetal derivatives is given in the first chapter, followed by a chapter on each of the three areas investigated. Relevant introductory literature is reviewed at the beginning of each chapter. Firstly, the ring expansion chemistry of unsaturated cyclic oxygen, nitrogen and sulfur acetal derivatives was explored for the development of a new methodology for the synthesis of medium ring heterocycles. This methodology has thus far proved unsuccessful in the synthesis of medium rings, although several interesting and unusual transformations were observed, such as the unexpected formation of an intriguing bicyclic enaminium salt. The use of thioacetals as directing groups for the palladium-mediated oxidation of terminal olefins was also explored, leading to the evolution of a new methodology for the catalytic, regioselective formation of either vinyl or allylic acetates. -
Stapled Peptides—A Useful Improvement for Peptide-Based Drugs
molecules Review Stapled Peptides—A Useful Improvement for Peptide-Based Drugs Mattia Moiola, Misal G. Memeo and Paolo Quadrelli * Department of Chemistry, University of Pavia, Viale Taramelli 12, 27100 Pavia, Italy; [email protected] (M.M.); [email protected] (M.G.M.) * Correspondence: [email protected]; Tel.: +39-0382-987315 Received: 30 July 2019; Accepted: 1 October 2019; Published: 10 October 2019 Abstract: Peptide-based drugs, despite being relegated as niche pharmaceuticals for years, are now capturing more and more attention from the scientific community. The main problem for these kinds of pharmacological compounds was the low degree of cellular uptake, which relegates the application of peptide-drugs to extracellular targets. In recent years, many new techniques have been developed in order to bypass the intrinsic problem of this kind of pharmaceuticals. One of these features is the use of stapled peptides. Stapled peptides consist of peptide chains that bring an external brace that force the peptide structure into an a-helical one. The cross-link is obtained by the linkage of the side chains of opportune-modified amino acids posed at the right distance inside the peptide chain. In this account, we report the main stapling methodologies currently employed or under development and the synthetic pathways involved in the amino acid modifications. Moreover, we report the results of two comparative studies upon different kinds of stapled-peptides, evaluating the properties given from each typology of staple to the target peptide and discussing the best choices for the use of this feature in peptide-drug synthesis. Keywords: stapled peptide; structurally constrained peptide; cellular uptake; helicity; peptide drugs 1. -
Introduction
1 Chapter 1 INTRODUCTION Significant research efforts in the field of transition metal catalysis have led to the development of powerful methods for the formation of C–C and C–heteroatom bonds. Appropriate design of the catalyst and reaction conditions, along with careful choice of the substrate, can enable new and challenging transformations to proceed in high yield and selectivity. In this thesis, three categories of such transformations are presented: cross- coupling reactions to form carbon–silicon bonds, aldehyde-selective Wacker oxidations of fluorinated olefins, and olefin metathesis catalyzed by aminophosphine-ligated ruthenium complexes. Nickel-catalyzed cross-coupling has proven to be a very effective strategy for the addition of organometallic reagents to unactivated alkyl electrophiles. In particular, secondary alkyl halides are useful coupling partners, despite previously being considered to exhibit poor reactivity in comparison to aryl and alkenyl electrophiles, due to challenging oxidative addition and competitive b-hydride elimination. While this class of reactions has predominantly been applied to the formation of C–C bonds, the extension of this strategy to the formation of C–B bonds presented by Fu and coworkers inspired the work presented in the second chapter of this thesis, which details the development of a nickel-catalyzed cross- coupling reaction of unactivated alkyl bromides and silylzinc nucleophiles, resulting in C–Si bond formation. A brief overview of established strategies to form C–Si bonds, as well as some of the current challenges, is discussed. The palladium-catalyzed Wacker oxidation is a powerful tool for the oxidation of terminal olefins. However, controlling the regioselectivity of this process (i.e. -
Hydroboration-Oxidation Of
molecules Article Hydroboration-Oxidation of (±)-(1α,3α,3aβ,6aβ) -1,2,3,3a,4,6a-Hexahydro-1,3-pentalenedimethanol and Its O-Protected Derivatives: Synthesis of New Compounds Useful for Obtaining (iso)Carbacyclin Analogues and X-ray Analysis of the Products Constantin I. Tănase 1,* ID , Florea G. Cocu 1, Miron Teodor Căproiu 2, Constantin Drăghici 2 and Sergiu Shova 3 1 National Institute for Chemical-Pharmaceutical Research and Development, Department of bioactive substances and pharmaceutical technologies, 112 Vitan Av., 031299, Bucharest-3, Romania; [email protected] 2 Organic Chemistry Center “C.D.Nenitescu”, Spectroscopy Laboratory, 202 B Splaiul Independentei, 060023 Bucharest, Romania; [email protected] (M.T.C.); [email protected] (C.D.) 3 Institute of Macromolecular Chemistry “Petru Poni”, Crystallography Department, 700478 Iasi, Romania; [email protected] * Correspondence: [email protected]; Tel.: +40-21-321-2117; Fax: +40-21-322-2917 Received: 22 October 2017; Accepted: 16 November 2017; Published: 24 November 2017 Abstract: Hydroboration-oxidation of 2α,4α-dimethanol-1β,5β-bicyclo[3.3.0]oct-6-en dibenzoate (1) gave alcohols 2 (symmetric) and 3 (unsymmetric) in ~60% yield, together with the monobenzoate diol 4a (37%), resulting from the reduction of the closer benzoate by the intermediate alkylborane. The corresponding alkene and dialdehyde gave only the triols 8 and 9 in ~1:1 ratio. By increasing the reaction time and the temperature, the isomerization of alkylboranes favours the un-symmetrical triol 9. The PDC oxidation of the alcohols gave cleanly the corresponding ketones 5 and 6 and the deprotection of the benzoate groups gave the symmetrical ketone 14, and the cyclic hemiketal 15, all in high yields.