New Chiral Auxiliaries for the [3+2]-Cycloaddition of Nonstabilised Azomethine Ylides
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Rhodium-Catalyzed Synthesis of Organosulfur Compounds Involving S-S Bond Cleavage of Disulfides and Sulfur
molecules Review Rhodium-Catalyzed Synthesis of Organosulfur Compounds Involving S-S Bond Cleavage of Disulfides and Sulfur Mieko Arisawa * and Masahiko Yamaguchi Department of Organic Chemistry, Graduate School of Pharmaceutical Sciences, Tohoku University, Aoba, Sendai 980-8578, Japan; [email protected] * Correspondence: [email protected]; Tel.: +81-22-795-6814 Academic Editor: Bartolo Gabriele Received: 17 July 2020; Accepted: 5 August 2020; Published: 7 August 2020 Abstract: Organosulfur compounds are widely used for the manufacture of drugs and materials, and their synthesis in general conventionally employs nucleophilic substitution reactions of thiolate anions formed from thiols and bases. To synthesize advanced functional organosulfur compounds, development of novel synthetic methods is an important task. We have been studying the synthesis of organosulfur compounds by transition-metal catalysis using disulfides and sulfur, which are easier to handle and less odiferous than thiols. In this article, we describe our development that rhodium complexes efficiently catalyze the cleavage of S-S bonds and transfer organothio groups to organic compounds, which provide diverse organosulfur compounds. The synthesis does not require use of bases or organometallic reagents; furthermore, it is reversible, involving chemical equilibria and interconversion reactions. Keywords: rhodium; catalysis; synthesis; organosulfur compounds; S-S bond cleavage; chemical equilibrium; reversible reaction 1. Introduction 1.1. Structure and Reactivity of Organic Disulfides Organosulfur compounds containing C-S bonds are widely used for the manufacture of drugs and materials. Compared with organic compounds containing oxygen, which is another group 16(6A) element, different properties appear owing to the large size and polarizability of sulfur atoms. -
B.Sc. III YEAR ORGANIC CHEMISTRY-III
BSCCH- 302 B.Sc. III YEAR ORGANIC CHEMISTRY-III SCHOOL OF SCIENCES DEPARTMENT OF CHEMISTRY UTTARAKHAND OPEN UNIVERSITY ORGANIC CHEMISTRY-III BSCCH-302 BSCCH-302 ORGANIC CHEMISTRY III SCHOOL OF SCIENCES DEPARTMENT OF CHEMISTRY UTTARAKHAND OPEN UNIVERSITY Phone No. 05946-261122, 261123 Toll free No. 18001804025 Fax No. 05946-264232, E. mail [email protected] htpp://uou.ac.in UTTARAKHAND OPEN UNIVERSITY Page 1 ORGANIC CHEMISTRY-III BSCCH-302 Expert Committee Prof. B.S.Saraswat Prof. A.K. Pant Department of Chemistry Department of Chemistry Indira Gandhi National Open University G.B.Pant Agriculture, University Maidan Garhi, New Delhi Pantnagar Prof. A. B. Melkani Prof. Diwan S Rawat Department of Chemistry Department of Chemistry DSB Campus, Delhi University Kumaun University, Nainital Delhi Dr. Hemant Kandpal Dr. Charu Pant Assistant Professor Academic Consultant School of Health Science Department of Chemistry Uttarakhand Open University, Haldwani Uttarakhand Open University, Board of Studies Prof. A.B. Melkani Prof. G.C. Shah Department of Chemistry Department of Chemistry DSB Campus, Kumaun University SSJ Campus, Kumaun University Nainital Nainital Prof. R.D.Kaushik Prof. P.D.Pant Department of Chemistry Director I/C, School of Sciences Gurukul Kangri Vishwavidyalaya Uttarakhand Open University Haridwar Haldwani Dr. Shalini Singh Dr. Charu Pant Assistant Professor Academic Consultant Department of Chemistry Department of Chemistry School of Sciences School of Science Uttarakhand Open University, Haldwani Uttarakhand Open University, Programme Coordinator Dr. Shalini Singh Assistant Professor Department of Chemistry Uttarakhand Open University Haldwani UTTARAKHAND OPEN UNIVERSITY Page 2 ORGANIC CHEMISTRY-III BSCCH-302 Unit Written By Unit No. Dr. Charu Pant 01, 02 & 03 Department of Chemistry Uttarakhand Open University Haldwani Dr. -
Heterocyclic Chemistry Updated
1 | Page Heterocyclic Chemistry By Dr Vipul Kataria Definition: A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements (N, O, S, P) as members of its ring. Introduction: Heterocyclic compounds may be defined as cyclic compounds having as ring members atoms of at least two different elements. It means the cyclic compound has one another atom different than carbon. Heterocyclic compounds have much importance in organic chemistry because of abundant presence of heterocyclic compounds in present pharmaceutical drugs. Like other organic compounds, there are several defined rules for naming heterocyclic compounds. IUPAC rules for nomenclature of heterocyclic systems (SPU 2012, 2 Marks) The system for nomenclature for heterocyclic systems was given by Hantzsch and Widman. The Hantzsch-Widman nomenclature is based on the type (Z) of the heteroatom; the ring size (n) and nature of the ring, whether it is saturated or unsaturated. This system of nomenclature applies to monocyclic 3-to-10-membered ring heterocycles. Type of the heteroatom: The type of heteroatom is indicated by a prefix as shown below for common hetreroatoms. Dr Vipul Kataria, Chemistry Department, V. P. & R. P. T. P. Science College, VV Nagar 2 | Pag e When two or more of the same heteroatoms are present, the prrefix di, tri, tetra… are used. e.g. dioxa, triaza, dithia. If the heteroatoms are different their atomic number in that grroup is considered. Thus order of numbering will be O, S, N, P, Si. Ring size: The ring size is indicated by a suffix according to Table I below. -
Heterocyclic Compounds with Biological Meaning
Heterocyclic compounds with biological meaning 1 Heterocyclic compounds Cyclic, organic compounds which besides carbon atoms have one or more heteroatom (other elements than C). Heterocyclic atoms: – nitrogen, N – sulphur, S – oxygen, O – phosphorus, P – barium, Ba – zinc, Zn – silicon, Si. 2 Heterocyclic compounds From the biological point of view, the most important are heterocyclic compounds with 5- and 6-membered rings, containing: S, N, O. Most of the heterocyclic compounds have their common names. Substituent’s position in the ring is described by : – number – position of heteroatom – no. 1 – Greek letter – describes carbon atom the closest to heteroatom as a, then β and γ, respectively. 3 Heterocyclic compounds Heterocyclic compounds are: • widespread in nature • biologically active • some of them are toxic (e.g. coniine, coumarin and derivatives). Occurrence in: • natural dyes - heme, chlorophyll • alkaloids – atropine and nicotine • amino acids such as tryptophan and histidine • enzymes, nucleoproteins, antibiotics • vitamins • many synthetic pharmaceuticals. 4 Heterocyclic compounds Aromatic character of heteroatom-containing ring comes from aromatic sextet which consists of: • „not bound” electron pairs of heteroatoms • four electrons π from carbon atoms Pyrrole Furane Thiophen 5 5- membered ring heterocyclic compounds with one heteroatom 5-membered rings: • contain mostly oxygen, sulphur and nitrogen • are flat • are aromatic 6 5- membered ring heterocyclic compounds with two heteroatoms oxazole imidazole thiazole pyrazole 7 5- membered ring heterocyclic compounds With one heteroatom With two heteroatoms Condensation products with benzene 8 Pyrrole and derivatives • Pyrrole derivatives: • pyrroline • pyrrolidone • proline, • Hydroksyproline. • Condensation’s products of pyrrole with benzene: – indole, – tryptophan, – serotonin. • Condensation’s products of pyrrole with formaldehyde: – heme – hemoglobin – billirubin – porphyrins – Biliverdin. -
Synthesis of Heterocyclic Compounds and Its Applications
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Arabian Journal of Chemistry (2015) xxx, xxx–xxx King Saud University Arabian Journal of Chemistry www.ksu.edu.sa www.sciencedirect.com ORIGINAL ARTICLE Synthesis of heterocyclic compounds and its applications Mohan N. Patel *, Parag S. Karia, Pankajkumar A. Vekariya, Anshul P. Patidar Department of Chemistry, Sardar Patel University, Vallabh Vidyanagar 388 120, Gujarat, India Received 28 February 2015; accepted 26 June 2015 KEYWORDS n n Abstract The octahedral ruthenium(II) complexes [Ru(L )(PPh3)2Cl2][L= biphenyl furanyl Heterocyclic compound; pyridine derivatives] were synthesized and characterized using LC–MS, IR spectroscopy, elemental Ruthenium(II) complexes; analysis and magnetic measurements. Complexes show enhancement in antibacterial activity Nucleic acid intercalating compared to free ligands. From the binding mode investigation by absorption titration and agent; viscosity measurement, it is observed that complexes bind to DNA via intercalation and also Cytotoxicity complexes promote the cleavage of supercoiled pUC19 plasmid DNA. Cytotoxicity analysis shows 100% mortality of Brine shrimp after 48 h. ª 2015 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/). 1. Introduction containing planar polycyclic hetero aromatic ligands (Ji et al., 2001). Studies on DNA-binding of the complexes are Recently, metal complexes as DNA interacting agents have crucial in development of nucleic acid interaction, chemother- been talk in medicinal inorganic chemistry (Fei et al., 2014; apy and photodynamic treatment (Huppert, 2008; Zhao et al., 2011; Abou-Hussen and Linert, 2009; Patel, Balasubramanian and Neidle, 2009; Georgiades et al., 2010). -
Heterocyclic Compou Review Cyclic Compounds and Its Biological
Original Article Heterocyclic compou nds and its biological activity a review Kedar Nathrao A Department of Chemistry, Dayanand Science College Latur -413512, Maharashtra, INDIA. Email: [email protected] Abstract Heterocyclic compounds are of particular interest in medicinal chemistry. The chemistry of heterocyclic compounds is one of the most complex branches of chemistry. It is equally interesting for its theoretical implication for the diversity of its synthetic procedure and for the physiological and industrial significances. More than 90% of new dru ges contain heterocycles and the interface between chemistry and biology, at which so much new scientific insight, discovery and application is taking place is crossed by hetrocyclic compounds. This review article covers the most active hetrocycles that ha ve shown considerable biological action as antifungal, anti -inflammatory antibacterial, anticonvulsant, antiallergic, herbicidal, anticancer activity. Majority of the large number of drugs being introduced in pharmacopeias every year are heterocyclic compounds. Keywords: Heterocyclic, biological activities. *Address for Correspondence: Dr. Kedar Nathrao A, Department of Chemistry, Dayanand Science College Latur -413512, Maharashtra, INDIA. Email: [email protected] Received Date: 25/05/2016 Revised Date: 12/0 6/2016 Accepted Date: 08/07/2016 therapeutically significant molecular sections, the Access this article online pharamacophores, the portion that can be deleted are of no interest as components of drug action; they are Quick Response Code: Website: regarded as the result of biosynthetic efforts on the parent www.statperson.com organism to construct materials for its own mateboli c or defensive purposes. Few heterocyclic compounds containing the five-membered oxadiazole nucleus possess 1,3,4 a diversity of us eful biological effects. -
Heterocyclic Compound –A Review
IOSR Journal of Applied Chemistry (IOSR-JAC) ISSN: 2278-5736, PP 43-46 www.iosrjournals.org Heterocyclic Compound –A Review Shital V. Hote 1, Shital P. Bhoyar2 1, 2 Department of Applied Chemistry, Shri Datta Meghe Polytechnic, Nagpur, India ABSTRACT : Main aim of this paper is to present the information regarding the Heterocyclic compounds that constitute the largest family of organic compounds. These are extremely important with wide array of synthetic, pharmaceutical and industrial applications. There is always a strong need for new and efficient processes in synthesizing of new Heterocycles. Several 1,3,4,5-tetraaryl-2 pyrazoline, 41 –piperazine, 3- methoxybenzofuran and thiazolidin-4-one substituted 1, 2, 4-triazole, 4- NO2, 2-OH and 4-Cl in phenyl ring at 5- position of pyrazoline ring of synthesized compounds. The new compounds were characterized using IR, 1H-NMR, 13C-NMR and mass spectra. Biological screening of some compounds is reported. Keywords: Synthesized compounds, heterocyclic substances. I. INTRODUCTION Compounds classified as heterocyclic probably constitute the largest and most varied family of organic compounds. After all, every carbocyclic compound, regardless of structure and functionality, may in principle be converted into a collection of heterocyclic analogs by replacing one or more of the ring carbon atoms with a different element. Even if we restrict our consideration to oxygen, nitrogen and sulfur (the most common heterocyclic elements), the permutations and combinations of such a replacement are numerous. Derivatives of the simple fused ring heterocycle purine constitute an especially important and abundant family of natural products. The amino compounds adenine and guanine are two of the complementary bases that are essential components of DNA. -
Colorimetric Determination of Indole Using 2,4,6-Trimethoxybenzaldehyde
International Journal of Engineering and Applied Sciences (IJEAS) ISSN: 2394-3661, Volume-3, Issue-2, February 2016 Colorimetric Determination of Indole using 2,4,6-trimethoxybenzaldehyde Wafaa M. Yousef, Saad A.Al-Tamrah, Basmah H. Al-Shammari 4 3 Abstract— Indole is an aromatic heterocyclic organic 5 compound. The indole nucleus is very important for many 2 6 N N + N1 natural and synthetic molecules with significant biological 7 H H activity. Compounds that contain an indole ring are called H indoles. Indoles are an important class of heterocycles not only Indole Canonical because they are among the most ubiquitous compounds in nature, but also because they have a wide range of biological Indole, a secondary amine, is a natural product of pancreatic activities. 2,4,6-Trimethoxybenzaldehyde can be used as digestion, bacterial action and putrefaction decomposition. antibacterial synergist. When indole was mixed with Indole is the precursor to many pharmaceuticals. The name 2,4,6-trimethoxybenzaldehyde at room temperature, no color indole is portmanteau of the words indigo and oleum, since was observed. However in the presence of concentrated indole was first isolated by treatment of the indigo dye with hydrochloric acid, a brown red complex is formed which has a oleum. Indole chemistry began with the study of the dye maximum absorbance at 488 nm. The parameters affecting this indigo. The indole ring is also found in many natural products reaction were studied in order to find the suitable conditions for such as the vinca alkaloids, fungal metabolites and marine the reaction to complete. The effect of the acid concentration, the natural products [2]. -
Isocyclicc Com- Poundscompounds
The Chemistry of Heterocycles Structure, Reactions, Syntheses, and Applications Mohammad Jafarzadeh Faculty of Chemistry, Razi University The Chemistry of Heterocycles, (Second Edition). By Theophil Eicher and Siegfried Hauptmann, Wiley-VCH Veriag GmbH, 2003 1 1 The Structure of Heterocyclic Compounds 1. The Structure of Heterocyclic Compounds • Molecules are defined by the type and number of atoms as well as by the covalent bonding within Mosthemt chemica. Therel arecompoundtwo mains consistypes tof ostructuref molecules: . The classification of such chemical compounds is base— Thed onatoms the structurform ae chainof thes-ealiphatic molecules(acyclic), whichcompounds is defined by the type and number of atoms as well as b—y thThee covalenatomst formbondina ringg withi- cyclicn themcompounds. There are two main types of structure: — The a t o m s form a chain - aliphatic (acyclic) compounds — The a t o m s form a ring - cyclic compounds CycliCyclicc compoundcompoundss iinn whicwhichh ththee rinringg isis madmadee upup ofof atomatomss ofof ononee elemenelementt onlonlyy areare callecalledd isocycliisocyclicc com- poundscompounds. If th.eIf rintheg consistring consistss of C-atomof C-atomss only,only, then thenwe speawe speakk of a carbocycliof a carbocyclicc compoundcompound,, e.g.: e.g.: NMe? O (4 - dimethylaminophenyl) pentazole cyclopenta -1,3 - diene isocyclic isocyclic und carbocyclic 2 Cyclic compounds with at least two different atoms in the ring (as ring atoms or members of the ring) are known as heterocyclic compounds. The ring itself is called a heterocycle. If the ring contains no C-atom, then we speak of an inorganic heterocycle, e.g.: MeO 2,4 - bis (4 - methoxyphenyl) - 1,3 - dithiadiphosphetan -2,4 - disulfide borazine (Lawesson - Reagent) If at least one ring atom is a C-atom, then the molecule is an organic heterocyclic compound. -
1,3-Dipolar Cycloaddition of Azomethine Ylides Generated from Aziridines in Supercritical Carbon Dioxide Paulo J
Tetrahedron Letters 47 (2006) 5475–5479 1,3-Dipolar cycloaddition of azomethine ylides generated from aziridines in supercritical carbon dioxide Paulo J. S. Gomes, Cla´udio M. Nunes, Alberto A. C. C. Pais, Teresa M. V. D. Pinho e Melo* and Luis G. Arnaut Department of Chemistry, Coimbra University, 3004-535 Coimbra, Portugal Received 8 March 2006; revised 26 May 2006; accepted 30 May 2006 Abstract—The 1,3-dipolar cycloaddition of azomethine ylides with DMAD in supercritical carbon dioxide is reported. The photo- lysis reaction conditions were optimized with a suitable adjustment of pressure, temperature, irradiation time and co-solvent concen- tration leading to a more efficient reaction than in neat acetonitrile. Similar results were observed using thermal reaction conditions. Supercritical carbon dioxide with a minute co-solvent addition is shown to be a very efficient medium for promoting this type of cycloadditions. Ó 2006 Elsevier Ltd. All rights reserved. Over the last decade, supercritical fluids (SCF) received ology for the synthesis of nitrogen-heterocyclic significant attention as a new class of environmentally compounds. We chose the 1,3-dipolar cycloaddition friendly solvents for organic synthesis. Supercritical flu- of azomethine ylides generated from aziridines as the ids have properties intermediate between the gas and the model reaction. Aziridines (1) undergo electrocyclic ring liquid phases that can be tuned simply by changing the opening in a disrotatory manner upon irradiation and pressure and temperature. In particular, changes of pres- conrotatory ring opening upon thermolysis, giving sure close to the critical point enable drastic changes in azomethine ylides (2), which participate in 1,3-dipolar density and viscosity. -
Visible Light Photoredox Catalysis with Transition Metal Complexes: Applications in Organic Synthesis Christopher K
Review pubs.acs.org/CR Visible Light Photoredox Catalysis with Transition Metal Complexes: Applications in Organic Synthesis Christopher K. Prier, Danica A. Rankic, and David W. C. MacMillan* Merck Center for Catalysis at Princeton University, Princeton, New Jersey 08544, United States References 5360 1. INTRODUCTION CONTENTS A fundamental aim in the field of catalysis is the development 1. Introduction 5322 of new modes of small molecule activation. One approach 2+ toward the catalytic activation of organic molecules that has 2. Photochemistry of Ru(bpy)3 5323 3. Net Reductive Reactions 5324 received much attention recently is visible light photoredox 3.1. Reduction of Electron-Poor Olefins 5324 catalysis. In a general sense, this approach relies on the ability of 3.2. Reductive Dehalogenation 5326 metal complexes and organic dyes to engage in single-electron- 3.3. Reductive Cleavage of Sulfonium and transfer (SET) processes with organic substrates upon Sulfonyl Groups 5328 photoexcitation with visible light. 3.4. Nitrogen Functional Group Reductions 5329 Many of the most commonly employed visible light 3.5. Radical Cyclizations 5330 photocatalysts are polypyridyl complexes of ruthenium and iridium, and are typified by the complex tris(2,2′-bipyridine) 3.6. Reductive Epoxide and Aziridine Opening 5331 2+ 3.7. Reduction-Labile Protecting Groups 5331 ruthenium(II), or Ru(bpy)3 (Figure 1). These complexes 4. Net Oxidative Reactions 5332 4.1. Functional Group Oxidations 5332 4.2. Oxidative Removal of the PMB Group 5334 4.3. Oxidative Biaryl Coupling 5335 4.4. Oxidative Generation of Iminium Ions 5335 4.5. Azomethine Ylide [3 + 2] Cycloadditions 5338 4.6. -
PERSONAL ACCOUNT Binap and Phosphoramidites As Privileged
PERSONAL ACCOUNT Carmen Nájera,*[a] and José M. Sansano*[b] Binap and phosphoramidites as Dedication ((optional)) privileged chiral ligands for the metal-catalyzed enantioselective 1,3-dipolar cycloaddition of azomethine ylides and dipolarophiles ((Insert Picture for Frontispiece here [18.0×18.0 cm])) [a] Title(s), Initial(s), Surname(s) of Author(s) including Corresponding Author(s) Department Institution Address 1 E-mail: [b] Title(s), Initial(s), Surname(s) of Author(s) Department Institution Address 2 Supporting information for this article is given via a link at the end of the document.((Please delete this text if not appropriate)) 1 PERSONAL ACCOUNT Abstract: Binap and phosphoramidites are privileged chiral starting from enolizable substrates I and electron-deficient ligands which have been tested in the coinage metal-catalyzed alkenes III promoted by coinage metals and the named chiral 1,3-dipolar cycloadditions of metalloazomethine ylides and ligands on the basis of the dipolarophile employed (Scheme 1). electrophilic alkenes. Silver(I), copper(II) and gold(I) salts have Rigid chiral metallodipoles II control of the final absolute been evaluated in all these reactions. Maleimides, acrylates, configuration of the up to four stereogenic centers of fumarates, 1,2-bis(phenylsulfonyl)ethylene and enones reacted polysubstituted proline derivatives IV. with imino esters giving the corresponding endo-prolinates such as HCV inhibitors in high diastereo- and enantioselectivity. In the case of nitroalkenes exo-4-nitroprolinates were obtained. Azlactones reacted with maleimides and acrylates to give pyrrolines only in the presence of binap-gold(I) complexes. The observed enantioselectivity and the mechanism of these 1,3-DC was studied by means of DFT calculations.