Iowa State University Capstones, Theses and Retrospective Theses and Dissertations Dissertations 1952 Steric and electronic influences in organolithium metalations John West Morton Jr. Iowa State College Follow this and additional works at: https://lib.dr.iastate.edu/rtd Part of the Organic Chemistry Commons Recommended Citation Morton, John West Jr., "Steric and electronic influences in organolithium metalations " (1952). Retrospective Theses and Dissertations. 13736. https://lib.dr.iastate.edu/rtd/13736 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]. NOTE TO USERS This reproduction is the best copy available. UMI STEBIC AND ELECTRONIC INFLUENCES IN ORGANOLITHimi MliiTALATIONS by John West Morton, jr. 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. In Charge of Major Work Signature was redacted for privacy. Head of Major Department Signature was redacted for privacy. Dean of'Graduate College Iowa State College 1952 UMI Number: DP12870 INFORMATION TO USERS The quality of this reproduction is dependent upon the quality of the copy submitted. Broken or indistinct print, colored or poor quality illustrations and photographs, print bleed-through, substandard margins, and improper alignment can adversely affect reproduction. In the unlikely event that the author did not send a complete manuscript and there are missing pages, these will be noted. 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Box 1346 Ann Arbor, Ml 48106-1346 ii ACKNOWLEDGMENT The author wishes to express his appreciation to Dr. Henry Gilman for the advice and helpful criticism given during the course of this Investigation. ili TABLE OF CONTENTS ACKNOWLEDGRfENT ii INTRODUCTION 1 HISTORICAL 6 Simple Metalations 6 Metalations with organo lithium compoiinds . 6 Metalations with organosodium and organopotassium compounds 37 Metalations with other organometallic compounds 59 Reductive Metalations 66 Metalations Accompanied by Dehydrogenation ... 67 Metalation and the Wurtz-Fittig Reaction .... 70 Metalation-Elimination Reactions of Vinyl Hal ides and Ethers 76 The Stevens and Sommelet Rearrangements 82 EXPERIMENTAL 96 Organometallic Compounds . 96 General remarks concerning preparation and use 9^ 2,4,6-Triphenylphenyllithium 97 Preparation from 2,4,6-triphenyl- bromobenzene and lithium 97 Preparation from 2,4,6-triphenylbromo- benzene and n-butyllithium 99 Mesityllithium 100 Preparation in ether-benzene 100 Preparation in ether 100 Phenylcalcium iodide 101 Preparation 101 Analysis 102 Metalations with Sterically Hindered Organo­ metallic Compounds 104 iv Metalation of thiophene with 2,4,6-triphenylphenyllithium 104 Metalation of £-bromoanisole with 2,4,6-triphenylphenyllithiuin 104 Eesorcinol dimethyl ether 106 Metalation with mesityllithium .... 106 Metalation with 2,4,6-triphenyl- phenyllithium . 106 Metalation of dibenzofuran with 2,4,6-triphenylphenyllithiiim 107 Reaction of 6-phenylphenanthridine with 2,4,6-triphenylphenyllithium 108 Fluorene 109 General procedure 109 Metalation with phenyllithiiun .... 110 Metalation with ^-tolyllithium .... 110 Metalation with mesityllithium .... 110 Metalation with 2,4,6-triphenyl- phenyllithium ........... Ill Triphenylmethane Ill General procedure . Ill Metalation with phenyllithium .... Ill Metalation with o-tolyllithium .... Ill Metalation with mesityllithium (attempted) 112 Metalation with 2,4,6-triphenyl- phenyllithium (attempted) 113 Ring Closure Reactions of Ethers . 114 Trityl methyl ether 114 Reaction with phenyllithium followed by hydrolysis 114 Reaction with phenyllithium followed by carbonation 115 Reaction with n-butyllithium followed by hydrolysis Il6 Reaction with n-butyllithium followed by carbonation ...... Il8 Reaction with benzylmagnesium chloride 119 Reaction with t-butylmagnesium chloride 120 V Reaction with phenylcalcium iodide (attempted) 121 Reaction of trityl phenyl ether with n-butyllithium 123 9-Phenyl-9-fluorenyl methyl ether 124 Reaction with phenyllithiuia 124 Reaction with n-butyllithium 125 Reaction of benzopinacol diphenyl ether with phenyllithium , 126 Miscellaneous Metalations . 12? Metalation of benzothlazole with n-butyl- magnesium bromide " 127 At -60° 127 At 0° 127 At 20-25° 128 Metalation of triphenylamine with phenyl- calcium iodide (attempted) 129 Dibenzothiophene-5-dioxide 13I Metalation with phenylcalcium iodide (attempted) I3I Metalation with n-butylraagnesium bromide (attempted) 132 Metalation of fluorene with lithium aluminum hydride (attempted) 134 In ether 134 In ether-benzene 135 Metalation of 9-phenylfluorene with n-butyllithium 135 Fercuration of 2-methoxynaphthalene .... I36 With mercuric nitrate at room temperature I36 With mercuric nitrate at 100° (attempted) 137 Broffiination of 2-methoxy-l-naphthyl- mercuric nitrate 137 vi lodination of 2-raethoxy-l-naphthyl- mercuric nitrate I38 Mercuration of 2-methoxynaphthalene by mercuric blsulfate (attempted) 139 Mercuration of dibenzothiophene (attempted) 140 With mercuric nitrate at room temperature ..... 140 With mercuric nitrate at 100° .... 140 With mercuric bisulfate 141 Metalation of thiophene with Indium chloride (attempted) 141 Miscellaneous Preparations and Reactions .... 142 Carbonation of 2,4,6-triphenylphenyl- lithium 142 Using Dry Ice 142 Using gaseous carbon dioxide 143 Preparation of l,3#5-'triphenylben2ene . 143 Preparation of 2,4,b-triphenyl- bromobenzene 144 Preparation of resorcinol dimethyl ether . 14^ Preparation of dibenzothiophene-5-dioxide . 146 Preparation of 9-phenyl-9-fluorenol .... 146 Preparation of 9-chloro-9-phenylfluorene . 148 Preparation of 1,1,1,2-tetraphenylethane . 148 Preparation of l,l,l-triphenyl-2,2,2-tri- methylethane 149 Preparation of trityl methyl ether .... 150 Using 100 per cent sulfuric acid . 1^0 Using 96 per cent sulfuric acid ... 151 Preparation of 9-phenyl-9-^luorenyl methyl ether 151 From 9-phenyl-9-chlorofluorene .... 1^1 From 9-phenyl-9-fluorenol 1^2 Preparation of trityl phenyl ether .... 153 Preparation of benzopinacol diphenyl ether. 154 Preparation of methyl o-iodobenzoate . 154 Preparation of 2-iodophenyldiphenyl- carbinol (attempted) ..... 155 vli DISCUSSION 157 Metalations with Sterically Hindered Organolithium Compounds 157 Ring Closure Reactions of Ethers 162 Miscellaneous Metalations 177 SUMMRY 185 1 INTRODUCTION The earliest use of a highly reactive organometallic compound as a metalating agent vras reported nearly half a century ago.^ At that time, the preparation of organoalkali compounds was both inconvenient and hazardousj the procedure usually employed was a reaction between the alkali metal and an R2Hg compound. For this reason, the extensive investi­ gation of the sjnnthetic possibilities of the organoalkali reagents, in metalations as well as in other reactions, was delayed until more convenient methods of preparation^* 3»4- became available. During the past two decades, enough data have accumu­ lated concerning the organoalkali metalations to enable many general conclusions to be drawn concerning orientation^'®'7 ^P. Schorigin, Be^., 41, 2723 (1908). %, Ziegler and H. Colonius, Ann.. 479. 135 (1930)• Oilman, E, A. Zoellner and W, M, Selby, J. Chem. So£., 51, 1957 (1932). ^A. A, Morton and I. Hechenbleikner, ibid.. '>8. I697 (1936). Oilman, H. B. ?/illis, T. H. Cook, F. J. Webb and R. N. Meals, ibid.. 667 (19^0). ^H. Oilman and 0. E. Brown, ibid.. 3208 (1940). ^W. Langham, R. Q. Brewster and H. Oilman, ibid.. 6"^. 545 (I94I). 2 and the relative directing influences of various groups in such reactions. Theories dealing with the general electronic character of raetalation reactions have also been pre­ sented,®' In only a few cases, however, have stereo­ chemical considerations been adduced to explain the outcome of such reactions,^^'although steric influences in other reactions of organometallic compounds have been studied A second aspect of raetalation which has received only scant attention is that of electronic influences in the metalated product in bringing about further reaction after metalation has taken place. The only systematic studies so far reported in this field have been the brilliant investi­ gations of Wittig and co-workers on the metalation-rearrange- ments of certain ethers and quaternary ammonium salts. 14 The studies described in the Experimental part of this dissertation were undertaken with a view toward exploring D, Roberts and D. Y. Curtin, ibid,. 68. l6^8 (194S). 9a. a. Morton, ibid.. 969 (1947). V, Sunthankar and H. Oilman, J. Ore. Chem.. I6, 8 (1951). M. Spatz, Iowa State Coll. J. 8ci., IZ, 129 (194-2), 1%. Gilman and (1952), 13r. c. Fuson, G. P. Speranza and R. Gaertner, ibid.. l*?. 1155 (19^0). ^^See the Section entitled "The Stevens and Sommelet Rearrangements" in the Historical part of this dissertation. 3 both of these