Essential Reagents for Organic Synthesis
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The Synthesis of Molecules Containing Quaternary Stereogenic Centers Via the Intramolecular Asymmetric Heck Reaction
The Synthesis of Molecules Containing Quaternary Stereogenic Centers via the Intramolecular Asymmetric Heck Reaction Reported by Eric P. Gillis April 19, 2007 INTRODUCTION The enantioselective synthesis of compounds containing quaternary stereocenters continues to be a challenging endeavor and is a field of intense interest and development.1,,,,2 3 4 5 From the perspective of methods development, the asymmetric synthesis of compounds containing quaternary stereocenters poses a distinct challenge due to the sterically congested environment in which C-C bonds must be formed and stereochemical information must be transferred. Existing asymmetric methods have been applied successfully in desymmetrization processes that transform prochiral quaternary centers into stereodefined quaternary centers. However, for processes in which a quaternary stereocenter is created directly via a C-C bond forming reaction, only a few asymmetric reactions have been fruitful. The diversity in the array of methods that exist for the synthesis of compounds containing quaternary stereocenters is necessitated in part because of the number of distinct quaternary stereocenter architectures that are possible (Scheme 1). The construction of acyclic quaternary stereocenters is particularly challenging due to the number of degrees of freedom associated with these structures. However, promising results for the construction of these stereocenters via allylation,6 allylic alklyation,7 and Michael addition8 have been reported recently. For the synthesis of cyclic quaternary stereocenters a number of methods have been employed successfully including the intramolecular Heck reaction,9 alkylation,10 arylation,11 and Michael addition12. Fused bicyclic quaternary stereocenters are generally accessed via the desymmetrization of a prochiral quaternary center. In this regard, theoretically any SCHEME 1. -
Aldrich FT-IR Collection Edition I Library
Aldrich FT-IR Collection Edition I Library Library Listing – 10,505 spectra This library is the original FT-IR spectral collection from Aldrich. It includes a wide variety of pure chemical compounds found in the Aldrich Handbook of Fine Chemicals. The Aldrich Collection of FT-IR Spectra Edition I library contains spectra of 10,505 pure compounds and is a subset of the Aldrich Collection of FT-IR Spectra Edition II library. All spectra were acquired by Sigma-Aldrich Co. and were processed by Thermo Fisher Scientific. Eight smaller Aldrich Material Specific Sub-Libraries are also available. Aldrich FT-IR Collection Edition I Index Compound Name Index Compound Name 3515 ((1R)-(ENDO,ANTI))-(+)-3- 928 (+)-LIMONENE OXIDE, 97%, BROMOCAMPHOR-8- SULFONIC MIXTURE OF CIS AND TRANS ACID, AMMONIUM SALT 209 (+)-LONGIFOLENE, 98+% 1708 ((1R)-ENDO)-(+)-3- 2283 (+)-MURAMIC ACID HYDRATE, BROMOCAMPHOR, 98% 98% 3516 ((1S)-(ENDO,ANTI))-(-)-3- 2966 (+)-N,N'- BROMOCAMPHOR-8- SULFONIC DIALLYLTARTARDIAMIDE, 99+% ACID, AMMONIUM SALT 2976 (+)-N-ACETYLMURAMIC ACID, 644 ((1S)-ENDO)-(-)-BORNEOL, 99% 97% 9587 (+)-11ALPHA-HYDROXY-17ALPHA- 965 (+)-NOE-LACTOL DIMER, 99+% METHYLTESTOSTERONE 5127 (+)-P-BROMOTETRAMISOLE 9590 (+)-11ALPHA- OXALATE, 99% HYDROXYPROGESTERONE, 95% 661 (+)-P-MENTH-1-EN-9-OL, 97%, 9588 (+)-17-METHYLTESTOSTERONE, MIXTURE OF ISOMERS 99% 730 (+)-PERSEITOL 8681 (+)-2'-DEOXYURIDINE, 99+% 7913 (+)-PILOCARPINE 7591 (+)-2,3-O-ISOPROPYLIDENE-2,3- HYDROCHLORIDE, 99% DIHYDROXY- 1,4- 5844 (+)-RUTIN HYDRATE, 95% BIS(DIPHENYLPHOSPHINO)BUT 9571 (+)-STIGMASTANOL -
United States Patent 0
1 3,667,923 United States Patent 0 ice Patented June 6, 1972 1 2 ‘I have discovered that anhydrous hydrogen cyanide $667,923 reacts readily with a quaternary ammonium borohydride PREPARATION OF LITHIUM, SODIUM AND and with the borohydrides of lithium and sodium at QUATERNARY AMMONIUM CYANOBORO atmospheric pressure in solvents for the borohydride, such HYDRIDES Robert C. Wade, Ipswich, Mass, assignor to Ventron as glyme, diglyme, triglyme, tetrahydrofuran and dimethyl Corporation, Beverly, Mass. formamide, or mixtures of these at a temperatures be No Drawing. Filed June 16, 1969, Ser. No. 833,722 tween 0° and the boiling point of the solvent to form Int. Cl. C01c 3/08; C01!) 35/00 the corresponding cyanoborohydride. The preferred sol US. Cl. 23-358 4 Claims vents are tetrahydrofuran and glyme because of their 10 convenient boiling points. Potassium borohydride does not react readily with ABSTRACT OF THE DISCLOSURE hydrogen cyanide in tetrahydrofuran or glyme presum The invention relates to the preparation of lithium, ably because of its lack of solubility in these solvents. sodium and quaternary ammonium cyanoborohydrides. However, it reacts with hydrogen cyanide in dimethyl These compounds are prepared by mixing substantially formamide similarly to the other borohydrides mentioned anhydrous hydrogen cyanide with a substantially an above. hydrous lithium or sodium or quaternary ammonium The reaction of the process of the invention appears to borohydride at a temperature between 0° C. and 100° C. take place in two stages. Thus, if the reaction mixture is in a substantially anhydrous solvent, such as tetrahydro initially maintained between about 10° and about 35° C. -
Reductions and Reducing Agents
REDUCTIONS AND REDUCING AGENTS 1 Reductions and Reducing Agents • Basic definition of reduction: Addition of hydrogen or removal of oxygen • Addition of electrons 9:45 AM 2 Reducible Functional Groups 9:45 AM 3 Categories of Common Reducing Agents 9:45 AM 4 Relative Reactivity of Nucleophiles at the Reducible Functional Groups In the absence of any secondary interactions, the carbonyl compounds exhibit the following order of reactivity at the carbonyl This order may however be reversed in the presence of unique secondary interactions inherent in the molecule; interactions that may 9:45 AM be activated by some property of the reacting partner 5 Common Reducing Agents (Borohydrides) Reduction of Amides to Amines 9:45 AM 6 Common Reducing Agents (Borohydrides) Reduction of Carboxylic Acids to Primary Alcohols O 3 R CO2H + BH3 R O B + 3 H 3 2 Acyloxyborane 9:45 AM 7 Common Reducing Agents (Sodium Borohydride) The reductions with NaBH4 are commonly carried out in EtOH (Serving as a protic solvent) Note that nucleophilic attack occurs from the least hindered face of the 8 carbonyl Common Reducing Agents (Lithium Borohydride) The reductions with LiBH4 are commonly carried out in THF or ether Note that nucleophilic attack occurs from the least hindered face of the 9:45 AM 9 carbonyl. Common Reducing Agents (Borohydrides) The Influence of Metal Cations on Reactivity As a result of the differences in reactivity between sodium borohydride and lithium borohydride, chemoselectivity of reduction can be achieved by a judicious choice of reducing agent. 9:45 AM 10 Common Reducing Agents (Sodium Cyanoborohydride) 9:45 AM 11 Common Reducing Agents (Reductive Amination with Sodium Cyanoborohydride) 9:45 AM 12 Lithium Aluminium Hydride Lithium aluminiumhydride reacts the same way as lithium borohydride. -
Part I. the Total Synthesis Of
AN ABSTRACT OF THE THESIS OF Lester Percy Joseph Burton forthe degree of Doctor of Philosophy in Chemistry presentedon March 20, 1981. Title: Part 1 - The Total Synthesis of (±)-Cinnamodialand Related Drimane Sesquiterpenes Part 2 - Photochemical Activation ofthe Carboxyl Group Via NAcy1-2-thionothiazolidines Abstract approved: Redacted for privacy DT. James D. White Part I A total synthesis of the insect antifeedant(±)-cinnamodial ( ) and of the related drimanesesquiterpenes (±)-isodrimenin (67) and (±)-fragrolide (72)are described from the diene diester 49. Hydro- boration of 49 provided the C-6oxygenation and the trans ring junction in the form of alcohol 61. To confirm the stereoselectivity of the hydroboration, 61 was convertedto both (t)-isodrimenin (67) and (±)-fragrolide (72) in 3 steps. A diisobutylaluminum hydride reduction of 61 followed by a pyridiniumchlorochromate oxidation and treatment with lead tetraacetate yielded the dihydrodiacetoxyfuran102. The base induced elimination of acetic acid preceded theepoxidation and provided 106 which contains the desired hydroxy dialdehydefunctionality of cinnamodial in a protected form. The epoxide 106 was opened with methanol to yield the acetal 112. Reduction, hydrolysis and acetylation of 112 yielded (t)- cinnamodial in 19% overall yield. Part II - Various N- acyl- 2- thionothiazolidineswere prepared and photo- lysed in the presence of ethanol to provide the corresponding ethyl esters. The photochemical activation of the carboxyl function via these derivatives appears, for practical purposes, to be restricted tocases where a-keto hydrogen abstraction and subsequent ketene formation is favored by acyl substitution. Part 1 The Total Synthesis of (±)-Cinnamodial and Related Drimane Sesquiterpenes. Part 2 Photochemical Activation of the Carboxyl Group via N-Acy1-2-thionothiazolidines. -
Reductive Amination with [11C]Formaldehyde: a Versatile Approach to Radiomethylation of Amines
International Journal of Organic Chemistry, 2012, 2, 202-223 http://dx.doi.org/10.4236/ijoc.2012.23030 Published Online September 2012 (http://www.SciRP.org/journal/ijoc) Reductive Amination with [11C]Formaldehyde: A Versatile Approach to Radiomethylation of Amines Chunying Wu1, Ruoshi Li1, Dorr Dearborn2, Yanming Wang1* 1Division of Radiopharmaceutical Science, Case Center for Imaging Research, Department of Radiology, Cleveland, USA 2Environmental Health, Case Western Reserve University, Cleveland, USA Email: *[email protected] Received February 16, 2012; revised March 24, 2012; accepted April 2, 2012 ABSTRACT Carbon-11 radiolabeled amines constitute a very important class of radioligands that are widely used for positron emis- 11 sion tomography (PET) imaging. Radiolabeling of amines is often achieved through radiomethylation using [ C]CH3I 11 or [ C]CH3OTf under basic conditions in a strictly anhydrous environment. Functional groups such as hydroxyl and carboxyl groups that are often present in the molecules are normally base sensitive and require protection and deprotec- tion, which substantially prolongs and complicates the radiolabeling process. Here we report a versatile approach to a series of C-11 radiolabeled amines prepared through reductive amination using [11C]formaldehyde. Using a variety of substrates bearing different functional groups, we demonstrate the general utility of this method. In contrast to conven- tional radiomethylation methods, the reductive amination using [11C]formaldehyde can be carried out in an aqueous environment relatively quickly without the need of protection of base-sensitive functional groups. Keywords: C-11 Formaldehyde; Radiomethylation; Reductive Amination; Positron Emission Tomography; Radiolabelling 1. Introduction probes must be labeled with positron-emitting radionu- clides such as carbon-11 or fluorine-18. -
Durham E-Theses
Durham E-Theses Functionalised Pyridyl- and Pyrimidyl- Boronic acids and derived new Biheteroaryls Smith, Amy Elizabeth How to cite: Smith, Amy Elizabeth (2005) Functionalised Pyridyl- and Pyrimidyl- Boronic acids and derived new Biheteroaryls, Durham theses, Durham University. Available at Durham E-Theses Online: http://etheses.dur.ac.uk/2751/ Use policy The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in Durham E-Theses • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders. Please consult the full Durham E-Theses policy for further details. Academic Support Oce, Durham University, University Oce, Old Elvet, Durham DH1 3HP e-mail: [email protected] Tel: +44 0191 334 6107 http://etheses.dur.ac.uk 2 University of Durham A Thesis Entitled Functionalised Pyridyl- and Pyrimidyl- Boronic Acids and Derived New Biheteroaryls Submitted by Amy Elizabeth Smith, B.Sc. (Hons) (Ustinov College) Department of Chemistry A Candidate for the Degree of Doctor of Philosophy 2005 The copyright of this thesis rests wnh the author or the university to which к was submitted. No quotation from It, or Information derived from It may be published wHhout the prior written consent of the author or university, and any Information derived from ท should be acknowledged. -
Diphosphine Complexes on Alpo4-Sepiolite Supports
catalysts Article Hydrogenation of α,β-Unsaturated Carbonyl Compounds over Covalently Heterogenized Ru(II) Diphosphine Complexes on AlPO4-Sepiolite Supports Verónica Caballero 1, Rafael Estevez 1, Diego Luna 1,* , Felipa M. Bautista 1 , Antonio A. Romero 1 , Laura Aguado-Deblas 1 , Jesús Hidalgo-Carrillo 1 and Isabel Romero 2 1 Departamento de Química Orgánica, Campus de Rabanales, Universidad de Córdoba, Ed. Marie Curie, 14014 Córdoba, Spain; [email protected] (V.C.); [email protected] (R.E.); [email protected] (F.M.B.); [email protected] (A.A.R.); [email protected] (L.A.-D.); [email protected] (J.H.-C.) 2 Departament de Química and Serveis Tècnics de Recerca, Universitat de Girona, C/M. Aurèlia Campmany, 69, E-17003 Girona, Spain; [email protected] * Correspondence: [email protected]; Tel.: +34-957212065 Abstract: In this work, the covalent immobilization of two ruthenium(II) complexes, II II i.e., [Ru Cl (bpea){(S)(-)(BINAP)}](BF4), 1, and [Ru Cl(bpea)(DPPE)](BF4), 2, where BINAP = 2,2’- bis(diphenylphosphino)-1,1’-binaphthyl and DPPE = 1,2-bis(diphenylphosphino)ethane, have been obtained (AlPO4-Sepiolite@1 and AlPO4-Sepiolite@2) by using a N-tridentate ligand N,N-bis-(2- pyridylmethyl)ethylamine (bpea), linked to an amorphous AlPO4-Sepiolite (20/80) inorganic support. Citation: Caballero, V.; Estevez, R.; This AlPO4-sepiolite support is able to immobilize the double amount of ruthenium complex (1.65%) Luna, D.; Bautista, F.M.; Romero, than the amorphous AlPO4 (0.89%). Both heterogenized complexes have been assessed as catalysts A.A.; Aguado-Deblas, L.; in the liquid phase hydrogenation of several substrates with carbonyl and/or olefinic double bonds Hidalgo-Carrillo, J.; Romero, I. -
200225128.Pdf
Members of the Examination Committee: Prof. Dr. ir. Nico Boon (Chairman) Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University Prof. Dr. Adrian Dobbs Department of Pharmaceutical, Chemical and Environmental Sciences, Faculty of Engineering and Science, University of Greenwich Dr. Steven De Jonghe Laboratory of Virology and Chemotherapy, Rega Institute for Medical Research, KU Leuven Prof. Dr. Serge Van Calenbergh Laboratory of Medicinal Chemistry, Faculty of Pharmaceutical Sciences, Ghent University Prof. Dr. ir. Matthias D’hooghe Department of Green Chemistry and Technology, Faculty of Bioscience Engineering, Ghent University Prof. Dr. ir. Marjan De Mey Department of Biotechnology, Faculty of Bioscience Engineering, Ghent University This work was supported by the Agency for Innovation by Science and Technology, Flanders (IWT- SBO project 100014) and the Special Research Fund (BOF project BOF14/DC1/032) Promotor: Prof. Dr. ir. Christian Stevens Department of Green Chemistry and Technology Faculty of Bioscience Engineering Ghent University Dean: Prof. Dr. ir. Marc Van Meirvenne Rector: Prof. Dr. ir. Rik Van de Walle Faculty of Bioscience Engineering 2019 ir. Laurens De Coen Synthesis and Preliminary Biological Evaluation of Furo- and Oxazolopyrimidine Analogues Thesis submitted in fulfilment of the requirements for the degree of Doctor (PhD) in Applied Biological Sciences: Chemistry and Bioprocess Technology Dutch translation of the title: Synthese en preliminaire biologische evaluatie van furo- en oxazolopyrimidines Please cite as: De Coen, L.; ‘Synthesis and Preliminary Biological Evaluation of Furo- and Oxazolopyrimidine Analogues’, PhD Dissertation, Ghent University, 2019 Cover illustration: Exploring Chemical Space (Laurens De Coen) ISBN number: 9789463572064 The author and the promotor give authorization to consult and copy parts of this work for personal use only. -
Applications of Boronic Acids in Organic Synthesis
Applications of Boronic Acids in Organic Synthesis A dissertation presented by Pavel Starkov in partial fulfilment of the requirements for the award of the degree of DOCTOR OF PHILOSOPHY at UNIVERSITY COLLEGE LONDON Department of Chemistry Christopher Ingold Laboratories University College London 20 Gordon Street WC1H 0AJ London Declaration This dissertation is the result of my own work. Where information has been derived from other sources it has been clearly indicated so and acknowledged accordingly. /Pavel Starkov/ ii Abstract This thesis describes progress on the application of boronic acids and borate esters as catalysts and reagents in synthetic organic synthesis, focusing on two areas: one-pot enolate formation/aldol reactions and amide bond formation. Chapter 1 introduces the reader to boronic acids and derivatives thereof, their methods of preparation and their use in synthetic organic chemistry as reactants, reagents and catalysts. Chapter 2 covers current chemical methods and cellular alternatives for amide bond formation. Here, we also discuss our use of boron reagents for the activation of carboxylic acids as well as amides. Chapter 3 introduces a new concept in catalytic aldol reactions, i.e. an alternative strategy to access boron enolates in situ. The work covers successful demonstration of the feasibility of such an approach on an intramolecular system. A novel variation of aerobic Chan–Evans– Lam coupling, an intramolecular coupling of an aliphatic alcohol with a boronic acid using catalytic copper, is also introduced Chapter 4 builds on our observations on gold catalysis and especially that in relation to electrophilic halogenations. Chapter 5 contains full details of the experimental procedures. -
Recent Advances of BINAP Chemistry in the Industrial Aspects
NEW TOOLS IN SYNTHESIS 1055 Recent Advances of BINAP Chemistry in the Industrial Aspects Hidenori Kumobayashi, Takashi Miura,* Noboru Sayo, Takao Saito, Xiaoyong Zhang Central Research Laboratory, Takasago International Corporation, 1-4-11 Nishi-yawata, Hiratsuka, Kanagawa 254-0073, Japan Fax (0463)25-2084; E-mail: [email protected] Received 24 April 2001 and ketones such as a-(acylamino)acrylic acids,6 enam- Abstract: New efficient synthetic methods of optically active BI- 7 8 ides, a,b-unsaturated carboxylic acids, allylic and ho- NAP [BINAP = 2,2’-bis(diphenylphosphino)-1,1’-binaphthyl] and 9 10 its variants are described. Application of these BINAP variants in moallylic alcohols, alkylidene lactones, alkenyl 10 11 12 asymmetric catalytic hydrogenation of prochiral ketones and olefins ethers, b-keto esters, b-hydroxyketones, and b-ami- to various industrially important compounds is discussed. noketones.12 Key words: BINAP ligands, ruthenium and iridium catalysts, Starting with the development of l-menthol process using asymmetric hydrogenation, ketones, unsaturated carboxylic acids BINAP–Rh catalyzed asymmetric isomerization of allyl- amines,5a we have been investigating catalytic asymmet- ric synthesis mainly based on BINAP chemistry for two Introduction decades and have developed various asymmetric synthet- ic processes. All of these results are based on the success Enantioselective syntheses have been gaining more and of the marvelous abilities of the BINAP ligands. Recently more importance in a wide range of fields such as pharma- the targets of asymmetric synthesis have become varied ceuticals, agrochemicals, food additives, aromachemicals and complicated, while BINAP sometimes shows its lim- and functional materials because the biological activities itation. -
Boronic Acids
Boronic Acids Boronic Acids www.alfa.com INCLUDING: • Boronic Esters • Oxazaborolidine Reagents • Coupling and Hydroboration Catalysts • Phosphine Ligands • Borylation Reagents www.alfa.com Where Science Meets Service Quality Boronic Acids from Alfa Aesar Alfa Aesar is known worldwide for a variety of chemical compounds used in research and development. Recognized for purity and quality, our products and brands are backed by technical and sales teams dedicated to providing you the best service possible. In this catalog, you will find details on our line of boronic acids, esters and related compounds, which are manufactured to the same exacting standards as our full offering of over 33,000 products. Also included in this catalog is a 28-page introduction to boronic acids, their properties and applications. This catalog contains only a selection of our wide range of chemicals and materials. Also included is a selection of novel coupling catalysts and ligands. Many more products, including high purity metals, analytical products, and labware are available in our main catalog or online at www.alfa.com. Table of Contents About Us _____________________________________________________________________________ II How to Order/General Information ____________________________________________________ III Introduction __________________________________________________________________________ 1 Alkenylboronic acids and esters _____________________________________________________ 29 Alkylboronic acids and esters ________________________________________________________