the nitro group in organic synthesis 2001 by noboru ono

THE NITRO GROUP IN ORGANIC SYNTHESIS The Nitro Group in Organic Synthesis. Noboru Ono Copyright © 2001 Wiley-VCH ISBNs: 0-471-31611-3 (Hardback); 0-471-22448-0 (Electronic) ORGANIC NITRO CHEMISTRY SERIES Managing Editor Dr. Henry Feuer Purdue University West Lafayette, Indiana 47907 USA EDITORIAL BOARD Hans H. Baer George Olah Ottawa, Canada Los Angeles, CA, USA Robert G. Coombes Noboru Ono London, England Matsuyama, Japan Leonid T. Eremenko C.N.R Rao Chernogolovka, Russia Bangalore, India Milton B. Frankel John H. Ridd Canoga Park, CA, USA London, England Philip C. Myhre Dieter Seebach Claremont, CA, USA Zurich, Switzerland Arnold T. Nielsen François Terrier China Lake, CA, USA Rouen, France Wayland E. Noland Heinz G. Viehe Minneapolis, MN, USA Louvain-la-Neuve, Belgium Also in the Series: Nitroazoles: The C-Nitro Derivatives of Five-Membered N- and N,O-Heterocycles by Joseph H. Boyer Nitrile Oxides, Nitrones, and Nitronates in Organic Synthesis: Novel Strategies in Synthesis by Kurt B.G. Torssell Nitro Compounds: Recent Advances in Synthesis and Chemistry Edited by Henry Feuer and Arnold T. Nielsen Nitration: Methods and Mechanisms by George A. Olah, Ripudaman Malhotra, and Sabhash C. Narong Nucleophilic Aromatic Displacement: The Influence of the Nitro Group by François Terrier Nitrocarbons by Arnold T. Nielsen THE NITRO GROUP IN ORGANIC SYNTHESIS Noboru Ono New York Chichester Weinheim Brisbane Singapore Toronto A JOHN WILEY & SONS, INC., PUBLICATION Designations used by companies to distinguish their products are often claimed as trademarks. In all in- stances where John Wiley & Sons, Inc., is aware of a claim, the product names appear in initial capital or ALL CAPITAL LETTERS. Readers, however, should contact the appropriate companies for more com- plete information regarding trademarks and registration. Copyright © 2001 by Wiley-VCH. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic or mechanical, including uploading, downloading, printing, decompiling, re- cording or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without the prior written permission of the Publisher. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 605 Third Avenue, New York, NY 10158-0012, (212) 850-6011, fax (212) 850-6008, E-Mail: PERMREQ @ WILEY.COM. This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold with the understanding that the publisher is not engaged in rendering profes- sional services. If professional advice or other expert assistance is required, the services of a competent professional person should be sought. ISBN 0-471-22448-0 This title is also available in print as ISBN 0-471-31611-3. For more information about Wiley products, visit our web site at www.Wiley.com. CONTENTS Series Foreword ix Preface xi Acknowledgments xiii Abbreviations xv 1. Introduction 1 2. Preparation of Nitro Compounds 3 2.1 Nitration of Hydrocarbons / 3 2.1.1 Aromatic Compounds / 3 2.1.2 Alkanes / 7 2.1.3 Activated C-H Compounds / 10 2.1.4 Alkenes / 11 2.1.5 Synthesis of = -Nitro Ketones / 16 2.1.6 Nitration of Alkyl Halides / 17 2.2 Synthesis of Nitro Compounds by Oxidation / 20 2.2.1 Oxidation of Amines / 20 2.2.2 Oxidation of Oximes / 21 3. The Nitro-Aldol (Henry) Reaction 30 3.1 Preparation of β -Nitro Alcohols / 31 3.2 Derivatives from β -Nitro Alcohols / 38 3.2.1 Nitroalkenes / 38 3.2.2 Nitroalkanes / 44 3.2.3 = -Nitro Ketones / 46 3.2.4 > -Amino Alcohols / 48 3.2.5 Nitro Sugars and Amino Sugars / 48 3.3 Stereoselective Henry Reactions and Applications to Organic Synthesis / 51 4. Michael Addition 70 4.1 Addition to Nitroalkenes / 70 v 4.1.1 Conjugate Addition of Heteroatom-Centered Nucleophiles / 70 4.1.2 Conjugate Addition of Heteroatom Nucleophiles and Subsequent Nef Reaction / 80 4.1.3 Conjugate Addition of Carbon-Centered Nucleophiles / 85 4.2 Addition and Elimination Reaction of β -Heterosubstituted Nitroalkenes / 100 4.3 Michael Addition of Nitroalkanes / 103 4.3.1 Intermolecular Addition / 103 4.3.2 Intramolecular Addition / 113 4.4 Asymmetric Michael Addition / 115 4.4.1 Chiral Alkenes and Chiral Nitro Compounds / 115 4.4.2 Chiral Catalysts / 118 5. Alkylation, Acylation, and Halogenation of Nitro Compounds 126 5.1 Alkylation of Nitro Compounds / 126 5.2 Acylation of Nitroalkanes / 128 5.3 Ring Cleavage of Cyclic α -Nitro Ketones (Retro-Acylation) / 131 5.4 Alkylation of Nitro Compounds via Alkyl Radicals / 133 5.5 Alkylation of Nitro Compounds Using Transition Metal Catalysis / 138 5.5.1 Butadiene Telomerization / 138 5.5.2 Pd-Catalyzed Allylic C-Alkylation of Nitro Compounds / 140 5.6 Arylation of Nitro Compounds / 147 5.7 Introduction of Heteroatoms to Nitroalkanes / 149 6 . Conversion of Nitro Compounds into Other Compounds 159 6.1 Nef Reaction (Aldehydes, Ketones, and Carboxylic Acids) / 159 6.1.1 Treatment With Acid (Classical Procedure) / 159 6.1.2 Oxidative Method / 160 6.1.3 Reductive Method / 164 6.1.4 Direct Conversion of Nitroalkenes to Carbonyl Compounds / 165 6.2 Nitrile Oxides and Nitriles / 167 6.3 Reduction of Nitro Compounds into Amines / 170 6.3.1 Ar-NH 2 From Ar-NO 2 / 170 6.3.2 R-NH 2 From R-NO 2 / 172 6.3.3 Oximes, Hydroxylamines, and Other Nitrogen Derivatives / 175 7. Substitution and Elimination of NO 2 in R–NO 2 182 7.1 R–Nu from R–NO 2 / 182 7.1.1 Radical Reactions (S RN 1) / 182 7.1.2 Ionic Process / 185 7.1.3 Intramolecular Nucleophilic Substitution Reaction / 191 7.1.4 Allylic Rearrangement / 192 7.2 R–H from R–NO 2 / 193 7.2.1 Radical Denitration / 193 7.2.2 Ionic Denitration / 211 7.3 Alkenes from R–NO 2 / 214 vi CONTENTS 7.3.1 Radical Elimination / 214 7.3.2 Ionic Elimination of Nitro Compounds / 218 8. Cycloaddition Chemistry of Nitro Compounds 231 8.1 Diels-Alder Reactions / 231 8.1.1 Nitroalkenes Using Dienophiles / 231 8.1.2 Asymmetric Diels-Alder Reaction / 243 8.2 1,3-Dipolar Cycloaddition / 249 8.2.1 Nitrones / 249 8.2.2 Nitrile Oxides / 258 8.2.3 Nitronates / 267 8.3 Nitroalkenes as Heterodienes in Tandem [4+2]/[3+2] Cycloaddition / 274 8.3.1 Nitroalkenes as Heterodienes / 275 8.3.2 Tandem [4+2]/[3+2] Cycloaddition of Nitroalkenes / 279 9. Nucleophilic Aromatic Displacement 302 9.1 S N Ar / 302 9.2 Nucleophilic Aromatic Substitution of Hydrogen (NASH) / 309 9.2.1 Carbon Nucleophiles / 310 9.2.2 Nitrogen and Other Heteroatom Nucleophiles / 316 9.2.3 Applications to Synthesis of Heterocyclic Compounds / 318 10. Synthesis of Heterocyclic Compounds 325 10.1 Pyrroles / 325 10.2 Synthesis of Indoles / 338 10.3 Synthesis of Other Nitrogen Heterocycles / 346 10.3.1 Three-Membered Ring / 346 10.3.2 Five- and Six-Membered Saturated Rings / 346 10.3.3 Miscellaneous / 355 Index 365 CONTENTS vii SERIES FOREWORD In the organic nitro chemistry era of the fifties and early sixties, a great emphasis of the research was directed toward the synthesis of new compounds that would be useful as potential ingredients in explosives and propellants. In recent years, the emphasis of research has been directed more and more toward utilizing nitro compounds as reactive intermediates in organic synthesis. The activating effect of the nitro group is exploited in carrying out many organic reactions, and its facile transformation into various functional groups has broadened the importance of nitro compounds in the synthesis of complex molecules. It is the purpose of the series to review the field of organic nitro chemistry in its broadest sense by including structurally related classes of compounds such as nitroamines, nitrates, nitrones, and nitrile oxides. It is intended that the contributors, who are active investigators in various facets of the field, will provide a concise presentation of recent advances that have generated a renaissance in nitro chemistry research. Henry Feuer Purdue University ix PREFACE The purpose of this book is to emphasize recent important advances in organic synthesis using nitro compounds. Historically, it was aromatic nitro compounds that were prominent in organic synthesis. In fact they have been extensively used as precursors of aromatic amines and their derivatives, and their great importance in industrial and laboratory applications has remained. This book is not intended to be a comprehensive review of established procedures, but it aims to emphasize new important methods of using nitro compounds in organic synthesis. The most important progress in the chemistry of nitro compounds is the improvement of their preparations; this is discussed in chapter 2. Environmentally friendly methods for nitration are emphasized here. In recent years, the importance of aliphatic nitro compounds has greatly increased, due to the discovery of new selective transformations. These topics are discussed in the following chapters: Stereoselective Henry reaction (chapter 3.3), Asymmetric Micheal additions (chapter 4.4), use of nitroalkenes as heterodienes in tandem [4+2]/[3+2] cycloadditions (chapter 8) and radical denitration (chapter 7.2). These reactions discovered in recent years constitute important tools in organic synthesis. They are discussed in more detail than the conventional reactions such as the Nef reaction, reduction to amines, synthesis of nitro sugars, alkylation and acylation (chapter 5). Concerning aromatic nitro chemistry, the preparation of substituted aromatic compounds via the S N Ar reaction and nucleophilic aromatic substitution of hydrogen (VNS) are discussed (chapter 9). Preparation of heterocycles such as indoles, are covered (chapter 10). Noboru Ono Matsuyama, Ehime xi ACKNOWLEDGMENTS Mr. Satoshi Ito, a graduate student in my group, has drawn all figures. It would have been impossible to complete the task of writing this book without his assistance. I would like to dedicate this book to the late Dr. Nathan Kornblum whom I met 30 years ago at Purdue University. Since then I have been engaged in the chemistry of nitro compounds. It is a pleasure to express my gratitude to all persons who contributed directly or indirectly to the accomplishment of the task. Dr. Henry Feuer advised me to write this monograph and also provided many helpful suggestions, for which I thank him. Thanks to professors Node, Vasella, Ballini, Ohno and Ariga, who kindly sent me their papers. I also express my gratitude to Dr. H. Uno for his careful proofreading. Finally, thanks to my wife Yoshiko and daughter Hiroko for their constant encouragement. Professors Kornblum and Ono. xiii [...]... single electron transfer reaction The Nitro Group in Organic Synthesis Noboru Ono Copyright © 2001 Wiley-VCH ISBNs: 0-471-31611-3 (Hardback); 0-471-22448-0 (Electronic) 1 INTRODUCTION The remarkable synthetic importance of nitro compounds has ensured long-standing studies of their utilization in organic synthesis Historically, nitro compounds, especially aromatic nitro compounds, are important for... acrylate with N2O4 in the presence of iodine, which is followed by the subsequent treatment with sodium acetate (Eq 2.26).51 The reaction of alkenes with nitrogen oxides in the presence of oxygen gives a mixture of vicinal nitro nitrates and dinitro compounds, which are precursors of nitroalkenes Thus, 1-nitrocyclooctene is prepared in 63–64% yield by the reaction of cyclooctene and N2O4 in the presence... for the preparation of nitroalkenes, which is based on the reaction with NO, has been reported Treatment of alkenes at ambient pressure of nitrogen monoxide (NO) at room temperature gives the corresponding nitroalkenes in fairly good yields along with β-nitroalcohols in a ratio of about 8 to 2 The nitroalcohol by- products are converted into the desired nitroalkenes by dehydration with acidic alumina in. .. NaNO3, in water is also a good method for the preparation of nitroalkenes.59 The regioselective addition of nitryl iodide to alkenes, followed by base-induced elimination, gives nitroalkenes Nitryl iodide is generally prepared by the reaction of AgNO2 and iodine 14 PREPARATION OF NITRO COMPOUNDS The synthetic applications of this reagent to the synthesis of nitroalkenes have been known since the 1960s.60... mechanism that proceeds in a dual mode, depending on the oxidation potential of the aromatic substrate; nitrogen dioxide reacts with ozone to form nitrogen trioxide, which oxidizes the aromatic substrate to form a radical cation, an intermediate in the ring substitution In the absence of an appropriate oxidizable substrate, the nitrogen trioxide reacts with another nitrogen dioxide to form dinitrogen pentoxide,... them are described precisely in vol 4 of Organic Synthesis For example, 1,4-dinitrobutane is prepared in 41–46% yield by the reaction of 1,4-diiodobutane with silver nitrite in diethyl ether.92b 1-Nitrooctane is prepared by the reaction with silver nitrite in 75–80% yield The reaction of silver nitrite with secondary halides gives yields of nitroalkanes of about 15%, whereas with tertiary halides the. .. fundamental and industrial applications because it provides nitro compounds, which may otherwise be difficult to synthesize by direct nitration methods Efficient synthetic methods for the conversion of primary amines into the nitro compounds are described in this section Saturated primary amines undergo oxidation reactions by ozone to give the corresponding nitroalkanes accompanied by several other compounds... PREPARATION OF NITRO COMPOUNDS A number of nitro compounds used in natural product synthesis have been prepared by the nitration of alkyl halides Some recent examples are summarized in Table 2.4 β -Nitro carbonyl compounds are important for synthesis of natural products The reaction of alkyl vinyl ketones with sodium nitrite and acetic acid in THF gives the corresponding β -nitro carbonyl compounds in 42–82%.105... prepared 2-(2-nitroethyl)-1,3-dioxolane from the corresponding 2-bromo compounds by various procedures (Eq 2.50).96 They found that IRA-900-NO− is best 2 for this conversion The preparation of nitroalkanes from alkyl halides has been used extensively for organic synthesis Interestingly, nitroalkylpyridine alkaloids, which have anti-macrofouling activity, are isolated from the Okinawan marine sponge Callyspongia... (2.63) Indirect conversion of oximes to nitro compounds via α-halo nitro compounds has provided a useful method for synthesis of nitro compounds, as shown in Scheme 2.1 Halogenation of oximes to halonitroso compounds has been achieved by a number of reagents, including chlorine,126 bromine,127 aqueous hypochlorous acid,126, t-butyl hypochlorite,37 and N-bromosuccinimide.128 The resulting halonitroso intermediate . THE NITRO GROUP IN ORGANIC SYNTHESIS The Nitro Group in Organic Synthesis. Noboru Ono Copyright © 2001 Wiley-VCH ISBNs: 0-471-31611-3 (Hardback); 0-471-22448-0 (Electronic) ORGANIC NITRO. Preparation of nitro compounds The Nitro Group in Organic Synthesis. Noboru Ono Copyright © 2001 Wiley-VCH ISBNs: 0-471-31611-3 (Hardback); 0-471-22448-0 (Electronic) synthesis, synthesis in water. Boyer Nitrile Oxides, Nitrones, and Nitronates in Organic Synthesis: Novel Strategies in Synthesis by Kurt B.G. Torssell Nitro Compounds: Recent Advances in Synthesis and Chemistry Edited by Henry Feuer