Oxidation of Alcohols to Aldehydes and Ketones

Transcription

1 Oxidation of Alcohols to Aldehydes and Ketones

2 BASIC REACTIONS IN ORGANIC SYNTHESIS EDITOR-IN-CHIEF: GABRIEL TOJO DEPARTMENT OF ORGANIC CHEMISTRY, FACULTY OF CHEMISTRY, UNIVERSITY OF SANTIAGO DE COMPOSTELA SANTIAGO DE COMPOSTELA SPAIN. Oxidation of Alcohols to Aldehydes and Ketones: A Guide to Current Common Practice, by Gabriel Tojo and Marcos Fernández

3 Oxidation of Alcohols to Aldehydes and Ketones A Guide to Current Common Practice GABRIEL TOJO and MARCOS FERNÁNDEZ

4 Authors: Gabriel Tojo Department of Organic Chemistry Faculty of Chemistry University of Santiago de Compostela Santiago De Compostela Spain Marcos Fernández Department of Organic Chemistry Faculty of Chemistry University of Santiago de Compostela Santiago De Compostela Spain Editor-on-Chief Gabriel Tojo Department of Organic Chemistry Faculty of Chemistry University of Santiago de Compostela Santiago De Compostela Spain Library of Congress Control Number: ISBN-10: ISBN-13: Printed on acid-free paper. ß2006 Springer ScienceþBusiness Media, Inc. All rights reserved. This work may not be translated or copied in whole or in part without the written permission of the publisher (Springer ScienceþBusiness Media, Inc. 233 Spring Street, New York, NY 10013, USA), except for brief excerpts in connection with reviews or scholarly analysis. Use in connection with any form of information storage and retrieval, electronic adaptation, computer software, or by similar or dissimilar methodology now known or hereafter developed is forbidden. The use in this publication of trade names, trademarks, service marks and similar terms, even if they are not identiwed as such, is not to be taken as an expression of opinion as to whether or not they are subject to proprietary rights. Printed in the United States of America springer.com

5 This book is dedicated to the thousands of scientists cited in the references that constructed our present knowledge on the oxidation of alcohols to aldehydes and ketones. Thanks to their collective evort, the preparation of medicines, pesticides, colorants and plenty of chemicals that make life more enjoyable, is greatly facilitated.

6 Acknowledgements We thank the stav of the library of the Faculty of Chemistry of the University of Santiago de Compostela (SPAIN) for their most serviceable help in collecting literature for the preparation of this book. vii

7 Preface There is natural selection in the synthetic organic laboratory. Successful reagents Wnd their way into specialized journals and tend to populate the researcher s benches. Sometimes, old species like active manganese dioxide in the oxidation of unsaturated alcohols are so well adapted to a certain reaction niche that they remain unchallenged for a long time. On other occasions, a successful new species like Dess Martin s periodinane enjoys a population explosion and very quickly inhabits a great number of laboratories. On the other hand, the literature is Wlled with promising new reagents that fell into oblivion because nobody was able to replicate the initial results on more challenging substrates. Very few synthetic operations in Organic Chemistry match the importance of the oxidation of alcohols to aldehydes and ketones. The present book, which is a monograph on this operation, is not primarily aimed at specialized researchers interested in the development of new oxidants. Rather, it was written with the objective of being a practical guide for any kind of scientist, be it a chemist of whatever sort, a pharmacologyst, a biochemist, or whoever is in the practical need to perform a certain alcohol oxidation in the most quick and reliable way. Therefore, a great emphasis is given to those oxidants that are employed most often in laboratories, because their ubiquity proves that they possess a greater reliability. Reagents appearing in only a few publications, regardless of promising potential, are only briexy mentioned. We prefer to err on the side of ignoring some good reagents, rather than including bad reagents that would lead researchers to loose their precious time. This book is meant to be placed near working benches in laboratories, rather than on the shelves of libraries. That is why full experimental parts for important oxidations are provided. Although plenty of references from the literature are facilitated, this book was written with the aim of avoiding as much as possible the need to consult original research articles. Many researchers do not have scientiwc libraries possessing numerous chemical journals ready available, and, many times, although such library might be ix

8 x Preface available, it is just inconvenient to leave the laboratory in order to consult some reference. Our aim is to facilitate a little practical help for anybody preparing new organic chemicals.

9 Abbreviations Ac acac Bn Boc BOM b.p. Bs BSA Bu t-bu Bz ca. CA CAN acetyl acetylacetonate benzyl t-butoxycarbonyl benzyloxymethyl boiling point benzenesulfonyl bis(trimethylsilyl) acetamide n-butyl tert-butyl benzoyl circa Chemical Abstracts cerium (IV) ammonium nitrate catalytic benzyloxycarbonyl cyclohexyl chemical ionization cat. Cbz or Z chex CI 18-Crown-6 1,4,7,10,13,16- hexaoxacyclo octadecane Cp CSA d DBU DCAA DCC cyclopentadienyl camphorsulfonic acid density 1,8-diazabicyclo [5.4.0]undec-7-ene dichloroacetic acid N,N-dicyclohexyl carbodiimide DDQ 2,3-dichloro-5,6- dicyano-1,4-benzoquinone de diastereomeric excess DIBAL-H diisobutylaluminum hydride DIPEA diisopropylethylamine, Hünig s base DMAP 4-(dimethylamino)- pyridine DMB 2,5-dimethoxybenzyl DME 1,2-dimethoxyethane DMF N,N-dimethylformamide DMP Dess-Martin periodinane DMSO EDC EE eq. Et Fl Fmoc g glac. Glc dimethyl sulfoxide 16,14e-2,1- (3-dimethylamino propyl)-3-ethyl carbodiimide hydrochloride 1-ethoxyethyl equivalent ethyl 9-phenylXuoren-9-yl 9-Xuorenyl methoxycarbonyl gram glacial glucose xi

10 xii h hour IBA o-iodosobenzoic acid IBX o-iodoxybenzoic acid imid. imidazole i-pr isopropyl L litre LDA lithium diisopropylamide m multiplet M mol/l MCPBA m-chloroperoxybenzoic acid Me methyl MEM (2-methoxyethoxy) methyl min. minute MOM methoxymethyl m.p. melting point MP p-methoxyphenyl Ms mesyl, methanesulfonyl MS molecular sieves MTBE methyl t-butyl ether MW molecular weight NBS N-bromosuccinimide NCS N-chlorosuccinimide NMO N-methylmorpholine N-oxide NMR nuclear magnetic resonance p. page PCC pyridinium chlorochromate PDC pyridinium dichromate Ph phenyl PMB or MPM p-methoxybenzyl PMBOM p-methoxy benzyloxymethyl PMP POM ppm PPTS Pr PTFA Py ref. Ref. r.t. SEM SET TBDPS TBS TEMPO TEA TES TFA TFAA THF THP T i TIPS TLC TMS TMSEt TPAP Tr Ts Abbreviations p-methoxyphenyl [(p-phenylphenyl)oxy] methyl parts per million pyridinium p-toluenesulfonate propyl pyridinium trixuoroacetate pyridine rexux reference room temperature 2-(trimethylsilyl) ethoxymethyl single electron transfer t-butyldiphenylsilyl t-butyldimethylsilyl 2,2,6,6,-tetramethyl-1- piperidinyloxy free radical triethylamine triethylsilyl trixuoroacetic acid trixuoroacetic anhydride tetrahydrofuran tetrahydropyran-2-yl internal temperature triisopropylsilyl thin layer chromatography trimethylsilyl 2-(trimethylsilyl)ethyl tetrapropylammonium perruthenate triphenylmethyl, trityl p-toluenesulfonyl

11 Contents 1. Chromium-Based Reagents Introduction Jones Reagent Sarett and Collins Reagents Pyridinium Dichromate (PDC) Pyridinium Chlorochromate (PCC) Election of Oxidant... 4 Section 1.1. References Jones Oxidation General Procedure for Transformation of Alcohols to Ketones by Jones Oxidation Protecting Group Sensitivity to Jones Oxidation Functional Group Sensitivity to Jones Oxidation In situ Deprotection and Oxidation of Alcohols to Ketones Obtention of Aldehydes by Jones Oxidation Side Reactions Section 1.2. References Collins Oxidation General Procedure for Oxidation of Alcohols to Aldehydes and Ketones by Collins Oxidation Functional Group and Protecting Group Sensitivity to Collins Oxidation Side Reactions Section 1.3. References Pyridinium Dichromate (PDC) General Procedure for Oxidation of Alcohols to Aldehydes and Ketones with Pyridinium Dichromate (PDC) Functional Group and Protecting Group Sensitivity to Oxidation with PDC xiii

12 xiv Contents Side Reactions Section 1.4. References Pyridinium Chlorochromate (PCC) General Procedure for Oxidation of Alcohols to Aldehydes and Ketones with Pyridinium Chlorochromate (PCC) Functional Group and Protecting Group Sensitivity to Oxidation with PCC Protecting Groups Alkenes Furan Rings Tertiary Allylic Alcohols Secondary Allylic Alcohols Homoallylic Alcohols ,6-Dihydroxyalkenes Hydroxyalkenes Epoxides Lactols Acetals ,2-Diols ,4-Diols ,5-Diols Nitrogen-Containing Compounds SulWdes Side Reactions Oxidative Breakage of a Carbon-Carbon Bond from an Intermediate Chromate Ester Formation of Conjugated Enones (or Enals) by Eliminations Subsequent to Alcohol Oxidation Chromate as Leaving-Group and Reactions Induced by the Acidic Nature of PCC Oxidative Dimerization of Primary Alcohols Oxidation Products SuVering Subsequent Reactions in Which PCC Plays no Role Side Reactions in Which Several of the Above Principles Operate Section 1.5. References Other Chromium-Based Oxidants Chromic Acid Chromium Trioxide and Pyridine... 86

13 Contents xv Dichromate Salts Halochromate Salts Oxidations Using Catalytic Chromium Compounds Miscellanea Section 1.6. References Activated Dimethyl Sulfoxide Introduction A Proposal for Nomenclature of Reactions Involving Activated DMSO Section 2.1. References PWtzner MoVatt Oxidation (Carbodiimide-Mediated MoVatt Oxidation) General Procedure for Oxidation of Alcohols by PWtzner MoVatt Method Functional Group and Protecting Group Sensitivity to PWtzner MoVatt Oxidation Side Reactions Section 2.2. References Albright Goldman Oxidation (Acetic Anhydride-Mediated MoVatt Oxidation) General Procedure for Oxidation of Alcohols by Albright Goldman Method Functional Group and Protecting Group Sensitivity to Albright Goldman Oxidation Side Reactions Section 2.3. References Albright Onodera Oxidation (Phosphorous Pentoxide-Mediated MoVatt Oxidation) General Procedure Albright Onodera Oxidation using the Taber ModiWcation Functional Group and Protecting Group Sensitivity to Albright Onodera Oxidation Section 2.4. References Parikh Doering Oxidation (Sulfur Trioxide-Mediated MoVatt Oxidation) General Procedure for Parikh Doering Oxidation Functional Group and Protecting Group Sensitivity to Parikh Doering Oxidation Side Reactions Section 2.5. References Omura Sharma Swern Oxidation (TFAA-Mediated MoVatt Oxidation)

14 xvi Contents General Procedure (Procedure A) for Oxidation of Alcohols with Omura Sharma Swern Method Functional Group and Protecting Group Sensitivity to Omura Sharma Swern Oxidation Side Reactions Section 2.6. References Swern Oxidation (Oxalyl Chloride-Mediated MoVatt Oxidation) General Procedure for Oxidation of Alcohols using Swern Oxidation Functional Group and Protecting Group Sensitivity to Swern Oxidation Reactions Performed in situ after a Swern Oxidation Side Reactions Activated DMSO as a Source of Electrophilic Chlorine Activated DMSO as a Source of Electrophilic Sulfur Transformation of Alcohols into Chlorides Methylthiomethylation Base-induced Reactions Acid-induced Reactions Formation of Lactones from Diols Section 2.7. References Corey Kim Oxidation General Procedure for Oxidation of Alcohols using the Corey Kim Method Functional Group and Protecting Group Sensitivity to Corey Kim Oxidations Side Reactions Section 2.8. References Other Alcohol Oxidations Using Activated DMSO Section 2.9. References Hypervalent Iodine Compounds Introduction Section 3.1. References Dess Martin Periodinane General Procedure for Oxidation of Alcohols using Dess Martin Periodinane Functional Group and Protecting Group Sensitivity to Dess Martin Oxidation

15 Contents xvii Reactions Performed in situ During a Dess Martin Oxidation Side Reactions Section 3.2. References o-iodoxybenzoic Acid (IBX) General Procedure for Oxidation of Alcohols with IBX Functional Group and Protecting Group Sensitivity to Oxidations with IBX Reactions Performed in situ During Oxidation with IBX Section 3.3. References Side Reactions Other Hypervalent Iodine Compounds Used for Oxidation of Alcohols Section 3.4. References Ruthenium-Based Oxidations Introduction Perruthenate and Ruthenate Ions Ruthenium Compounds in a Lower Oxidant State Section 4.1. References Ruthenium Tetroxide General Procedure for Oxidation of Secondary Alcohols with Stoichiometric RuO General Procedure for Oxidation of Alcohols with Catalytic RuO Functional Group and Protecting Group Sensitivity to Ruthenium Tetroxide Section 4.2. References Tetra-n-Propylammonium Perruthenate (TPAP) (Ley Oxidation) General Procedure for Oxidation of Alcohols with TPAP Functional Group and Protecting Group Sensitivity to Oxidation with TPAP Reactions Performed in situ During an Oxidation with TPAP Side Reactions Section 4.3. References Oxidations Mediated by TEMPO and Related Stable Nitroxide Radicals (Anelli Oxidation) Introduction

16 xviii Contents Section 5.1. References TEMPO-Mediated Oxidations General Procedure for Oxidation of Alcohols with TEMPO NaOCl (Anelli s Protocol) General Procedure for Oxidation of Alcohols with TEMPO PhI(OAc) 2 (Protocol of Piancatelli and Margarita) Functional Group and Protecting Group Sensitivity to Oxidations Mediated by TEMPO Side Reactions Section 5.2. References Oxidations by Hydride Transfer from a Metallic Alkoxide Introduction Section 6.1. References Oppenauer Oxidation Experimental Conditions Mechanism Oxidations Using Sodium or Potassium Alkoxides Recent Developments General Procedure for Oppenauer Oxidation under Standard Conditions Functional Group and Protecting Group Sensitivity to Oppenauer Oxidation Reactions Performed in situ During an Oppenauer Oxidation Side Reactions Section 6.2. References Mukaiyama Oxidation General Procedure for Mukaiyama Oxidation Functional Group and Protecting Group Sensitivity to Mukaiyama Oxidation Side Reactions Section 6.3. References Fétizon s Reagent: Silver Carbonate on Celite Introduction Section 7.1. References Fétizon s Oxidation Preparation of Fétizon s Reagent General Procedure for Oxidation of Alcohols with Fétizon s Reagent Functional Group and Protecting Group Sensitivity to Fétizon s Oxidation

17 Contents xix Side Reactions Section 7.2. References Selective Oxidations of Allylic and Benzylic Alcohols in the Presence of Saturated Alcohols Introduction Section 8.1. References Manganese Dioxide (MnO 2 ) General Procedure for Selective Oxidation of Allylic, Benzylic and Propargylic Alcohols with MnO Functional Group and Protecting Group Sensitivity to Oxidation with MnO Reactions Performed in situ During Oxidations with MnO Side Reactions Barium Manganate: More Reactive and Reproducible Alternative to Active MnO General Procedure for Selective Oxidation of Allylic, Benzylic and Propargylic Alcohols in Presence of Saturated Alcohols, using Barium Manganate (BaMnO 4 ) Section 8.2. References ,3-Dichloro- 5,6-dicyano-p-quinone (DDQ) General Procedure for Selective Oxidation of Unsaturated Alcohols in Presence of Saturated Ones using DDQ Functional Group and Protecting Group Sensitivity to Oxidation with DDQ Side Reactions Section 8.3. References Other Oxidants Section 8.4. References Selective Oxidations of Primary Alcohols in the Presence of Secondary Alcohols Introduction Section 9.1. References TEMPO-Mediated Oxidations Section 9.2. References RuCl 2 (PPh 3 ) General Procedure for Selective Oxidation of Primary Alcohols in Presence of Secondary Ones Employing RuCl 2 (PPh 3 )

18 xx Contents Section 9.3. References Other Oxidants Section 9.4. References Selective Oxidation of Primary Alcohols via Silyl Ethers Section 9.5. References Selective Oxidations of Secondary Alcohols in Presence of Primary Alcohols Introduction Section References Reaction with Electrophilic Halogen Sources General Procedure for Selective Oxidation of Secondary Alcohols in Presence of Primary Ones, using Steven s Protocol (Sodium Hypochlorite in Acetic Acid) Section References Oxidation of Intermediate Alkyltin Alkoxides General Procedure for Selective Oxidation of Secondary Alcohols in Presence of Primary Ones by Treatment of Intermediate Tin Alboxides with Bromine or N Bromosuccinimide Section References Other Oxidants Section References Selective Oxidations of Secondary Alcohols via Protection of Primary Alcohols Section References Index