ORGANO MAIN GROUP CHEMISTRY ORGANO MAIN GROUP CHEMISTRY KIN-YA AKIBA A JOHN WILEY & SONS, INC., PUBLICATION Copyright © 2011 by John Wiley & Sons, Inc All rights reserved Published by John Wiley & Sons, Inc., Hoboken, New Jersey Published simultaneously in Canada No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning, or otherwise, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 750-4470, or on the web at www.copyright.com Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) 748-6011, fax (201) 748-6008, or online at http://www.wiley.com/go/permission Limit of Liability/Disclaimer of Warranty: While the publisher and author have used their best efforts in preparing this book, they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose No warranty may be created or extended by sales representatives or written sales materials The advice and strategies contained herein may not be suitable for your situation You should consult with a professional where appropriate Neither the publisher nor author shall be liable for any loss of profit or any other commercial damages, including but not limited to special, incidental, consequential, or other damages For general information on our other products and services or for technical support, please contact our Customer Care Department within the United States at (800) 762-2974, outside the United States at (317) 572-3993 or fax (317) 572-4002 Wiley also publishes its books in a variety of electronic formats Some content that appears in print may not be available in electronic formats For more information about Wiley products, visit our web site at www.wiley.com Library of Congress Cataloging-in-Publication Data: Akiba, Kin-ya, 1936– Organo main group chemistry / Kin-ya Akiba p cm ISBN 978-0-470-45033-8 (pbk.) Organic compounds Organic compounds– Synthesis Carbon compounds Chemistry Organic I Title QD251.3.A35 2011 547–dc22 2010050401 Printed in Singapore oBook ISBN: 9781118025918 ePDF ISBN: 9781118025871 ePub ISBN: 9781118025888 10 CONTENTS Preface ix Main Group Elements and Heteroatoms: Scope and Characteristics 1.1 1.2 Aufbau Principle and Sign of Orbitals / Electronic Configuration of an Atom: Main Group Elements and Heteroatoms / 1.3 Fundamental Properties of Main Group Elements / 1.4 Acidity of Carboxylic Acid and Substituent Effect / 1.5 Heteroatom Effect / 10 1.5.1 Stabilization of α-Carbocation by Resonance: Stereoelectronic Effect / 10 1.5.2 Coordination with Lewis Acids / 15 References / 16 Notes 1: Electronegativity 17 Notes 2: Importance of Formal Logic-I: Oxidation Number and Formal Charge 19 Importance of Formal Logic-II: Octet Rule, Eighteen-Electron Rule, Hypervalence 23 Notes 3: v vi CONTENTS Main Group Element Effect 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 25 What Is Main Group Element Effect? / 25 Single Bond Energy and π –Bond Energy / 27 Hypervalent Compound / 31 Effect of Hypervalent Bond (1): 3c–4e Bond and Structure / 33 Effect of Hypervalent Bond (2): Apicophilicity and Pseudorotation / 41 Effect of Hypervalent Bond (3): Ligand Coupling Reaction (LCR) and Edge Inversion / 45 Effect of σX−C / 46 ∗ Effect of σX−C / 48 Notes 4: (σ , σ ∗ ) and (π, π ∗ ): HMO (Hueckel Molecular Orbital) and Electrocyclic Reaction Lithium, Magnesium, and Copper Compounds 57 63 3.1 3.2 3.3 Synthesis / 64 Structure / 66 Reaction / 68 3.3.1 Deprotonation as Base / 69 3.3.2 Nucleophilic Reaction / 72 3.3.3 Conjugate Addition of Lithium Dimethylcuprate / 76 References / 77 Boron and Aluminum Compounds 79 4.1 Synthesis / 80 4.2 Structure / 82 4.3 Reaction / 84 References / 88 Silicon, Tin, and Lead Compounds 91 5.1 Synthesis / 92 5.2 Reaction / 94 5.3 Organotin and Lead Compounds / 100 References / 104 Notes 5: Stable Carbene and Its Complex Phosphorus, Antimony, and Bismuth Compounds 6.1 6.2 Phosphorus Compounds / 112 Synthesis of Organophosphorus Compounds / 113 105 111 CONTENTS vii 6.3 6.4 6.5 6.6 6.7 6.8 Tertiary Phosphine and Its Nucleophilic Reaction / 115 Arbuzov Reaction / 117 Perkow Reaction / 118 Synthesis of Optically Active Phosphines / 119 Ylide and Wittig Reaction and Related Ones / 123 Reactions of Phosphonium Salts and Formation of Phosphoranes / 131 6.9 Freezing BPR and Its Effect / 138 6.10 Antimony and Bismuth Compounds / 143 References / 146 Notes 6: Dreams of Staudinger and Wittig 149 Notes 7: Stereochemistry in Nucleophilic Substitution of MX4 -type Compounds: Inversion or Retention 155 Sulfur, Selenium, and Tellurium Compounds 159 7.1 7.2 7.3 7.4 Sulfur Compounds / 160 Synthesis of Organosulfur Compounds / 160 Reactions of Organosulfur Compounds / 166 Structure and Reaction of Hypervalent Organosulfur Compounds / 170 7.5 Selenium and Tellurium Compounds / 175 References / 178 Notes 8: Inversion Mechanism of NH3 and NF3 : Vertex Inversion or Edge Inversion Organohalogen Compounds: Fluorine and Iodine Compounds 181 187 8.1 Synthesis of Chlorine and Bromine Compounds / 188 8.2 Fluorine Compounds / 190 8.3 Iodine Compounds / 195 References / 199 Atrane and Transannular Interaction: Formation of Hypervalent Bond 9.1 Introduction / 201 9.2 Silatrane and Atrane / 202 9.3 Transannular Interaction (1) / 208 9.4 Transannular Interaction (2) / 210 References / 211 201 viii CONTENTS 10 Unsaturated Compounds of Main Group Elements of Third Period and Heavier 213 10.1 10.2 Introduction / 213 Unsaturated Bonds of Group 15 Elements of Third Period and Heavier / 215 10.3 Unsaturated Bonds of Group 14 Elements of Third Period and Heavier / 219 10.4 Aromatic Compounds of Group 14 Elements / 222 References / 223 11 Ligand Coupling Reaction 225 11.1 11.2 Introduction / 225 Selectivity of Ligand Coupling Reaction: Theoretical Investigation / 226 11.3 Ligand Coupling Reaction of Organic Compounds of Phosphorus, Antimony, and Bismuth / 227 11.4 Ligand Coupling Reaction of Organic Compounds of Sulfur, Selenium, and Tellurium / 237 11.5 Ligand Coupling Reaction of Organoiodine Compounds / 241 References / 245 Notes 9: Hexavalent Organotellurium Compounds 247 12 Hypervalent Carbon Compounds: Can Hexavalent Carbon Exist? 251 12.1 12.2 Introduction / 251 Attempts for Pentacoordinate Hypervalent Carbon Species / 253 12.3 Synthesis of Pentacoordinate Hypervalent Carbon Species (10-C-5) and Bond Switching at Carbon and Boron / 254 12.4 Attempts to Hexacoordinate Hypervalent Carbon Species (12-C-6) / 259 References / 262 Notes 10: Main Group Element Porphyrins 265 Index 269 PREFACE The fundamental and essential element of organic compounds is, without a doubt, carbon There are excellent textbooks on organic chemistry, such as those written by McMurry, Jones, Jr., Morrison and Boyd, and Vollhardt and Schore These are referred in undergraduate courses internationally and are available in almost all bookstores dealing with science On the other hand, main group element chemistry has been traditionally described in inorganic chemistry textbooks before transition metal chemistry (such as in Cotton and Wilkinson, Huheey, Housecroft and Sharpe, and Schriver, Atkins and Langford) Heteroatoms, that is, elements of groups 15, 16, and 17 bearing unshared electron pair (s) and elements of groups 1, 2, and 12–18 in which valence electrons reside in sp orbitals, are important elements contained in carbon skeletons; they modify the character of carbon compounds The chemistry of the sp elements, namely, main group elements, has been investigated primarily to discover and to use their unique characteristics, as compared to carbon There are books and reviews on the chemistry of each main group element dealing with detailed and advanced researches However, there is no concise book on organic chemistry focusing on the synthesis, structure, and reaction of main group element compounds This book, Organo Main Group Chemistry, consists of 12 chapters and 10 notes Chapters 1–8 describe the fundamental and basic organic chemistry of main group elements that are classified according to their groups These are appropriate for use as a textbook Chapters 9–12 note the recent advances in the related field of hypervalent (higher coordinate) and hypovalent (lower coordinate) compounds of main group elements The notes supplement the chapters by explaining basic ideas and also describing recent research in related fields ix x PREFACE Chapter describes the fundamental properties of main group elements and explains the difference between a heteroatom and a main group element Notes 1–3 remind readers of basic ideas of chemistry, emphasizing the importance of formal logic Chapter describes precisely the main group element effect in contrast to the heteroatom effect Also, the effect of hypervalent bond, which does not appear in heteroatoms of a second period, is explained in considerable detail Note is a refresher on Hueckel molecular orbital (HMO) and electrocyclic reaction Chapters 3–8 discuss the synthesis, structure, and reaction of main group element compounds Chapter deals with groups and 2, namely, lithium, magnesium, and copper compounds Chapter describes boron and aluminum compounds, and Chapter explains silicon, tin, and lead compounds Chapter describes compounds of group 15 elements of phosphorus, antimony, and bismuth The synthesis of optically active phosphines, reaction of ylides, formation of phosphoranes, and effect of freezing pseudorotation are explained using phosphorus as a representative element These are essentially common for compounds of groups 14, 15, 16, and 17, and the chemistry has been developed on phosphorus before that of sulfur because of its importance, and also for stability in handling the compounds Note mentions historical aspects of researches on hypervalent compounds, which stemmed from the dreams of Staudinger and Wittig Note explains possible mechanisms on nucleophilic substitution of MX4 -type compounds Chapter describes compounds of group 16 elements of sulfur, selenium, and tellurium Note explains the mechanism and dynamic aspects of edge inversion Chapter deals with halogen compounds, with emphasis on fluorine and iodine compounds because organochlorine and bromine compounds are quite common and are treated well in textbooks for undergraduates Chapters 9, 10, and 11 describe recent advances in researches on main group elements of third period and heavier ones Chapter deals with the formation of hypervalent (higher coordinate) bonds, including silatrane and atrane Chapter 10 explains the synthesis of hypovalent (lower coordinate) compounds of groups 14, 15, and also that of aromatic compounds Chapter 11 illustrates ligand coupling reaction (LCR) on compounds of groups 15, 16, and iodine Note illustrates the synthesis of hexavalent tellurium compounds and that of a cation and an anion of pentacoordinate tellurium bearing the same kind of ligand Chapter 12 describes the synthesis of hypervalent carbon compounds, namely, pentacoordinate hypervalent carbon species (10-C-5), and attempts to hexacoordinate (hypervalent) carbon species (12-C-6), supported by theoretical calculations Note 10 illustrates the synthesis of main group element porphyrins of Sb and P in which central atoms are hypervalent References throughout this book are based on arbitrary choices by the author, and not at all comprehensive Particularly, the references in Chapters 1–8, except in Chapter 2, contain basic and fundamental references on the fields, accompanied by newer ones, where appropriate Most consist of references that the author has read carefully before and found to contain basic experimental results They PREFACE xi were used in lectures for undergraduate and graduate courses in Japanese universities Chapters 9–12 deal with recent advances in the related fields; therefore, references are cited to show basic ideas and recent researches References for notes were chosen based on the same standpoint as for the chapters Advanced series, such as “Comprehensives” of organic synthesis, organometallic, and heterocyclic chemistry and the “Patai’s series” on functional groups were not cited as references In Japanese bookstores dealing with sciences, we find a variety of textbooks originally written in English that had been translated into Japanese For instance, seven textbooks mentioned at the beginning of this preface, except the one by Housecroft and Sharpe, had been translated and are being used in Japanese universities There are similar books and countless review articles on specialized topics originally written in Japanese The Chemical Society of Japan has been editing the Encyclopedia of Experimental Chemistry (Jikken Kagaku Kouza) The recent fifth edition consists of 30 volumes; it includes all fields of chemical sciences However, the articles written in Japanese can neither be referred in original research papers of international journals, nor in books written in English It is a great pity, but it is the reality This book was originally written in Japanese and published by Kodansha Scientific, Inc., in Tokyo under the title Yuuki Tenkei Genso Kagaku (translated into English as Organo Main Group Chemistry) in 2008 I am grateful to Kodansha Scientific, Inc., for allowing me to use all the equations and schemes in the Japanese edition, without any restriction, to write the present revised English version I am thankful to the international reviewers nominated by John Wiley & Sons, who heartily recommended to publish this book in English Also, I wish to acknowledge the patience and support of my family, and the kind cooperation, skill, and good cheer of the editors at Wiley Professor Emeritus of Hiroshima University Tokyo, Japan November 2010 Kin-ya Akiba 260 HYPERVALENT CARBON COMPOUNDS: CAN HEXAVALENT CARBON EXIST? 0.74 (a) C9 C1 C8 0.74 0.74 1.62 0.77 1.62 0.97 0.97 B1 N1 0.70 0.88 N2 0.70 0.88 1.74 0.77 B1' 1.74 1.32 3.06 4.80 (b) N1 B1 0.77 2.29 0.97 1.74 0.77 N2 3.06 4.80 Figure 12.4 Bond switching diagram of N–B · · · N on the anthracene skeleton (C1 , C9 , C8 ) (18, 19, 20) (a) Dotted circle represents covalent radius: N, 0.70; B, ˚ Solid circle represents 110% of covalent radius: N, 0.77; 0.88; C, 0.74 A ˚ B, 0.97 A (b) Large half circle represents 110% of van der Waals radius ˚ Others represent 110% of covalent radius of N and B of B: 2.29 A ATTEMPTS TO HEXACOORDINATE HYPERVALENT CARBON SPECIES (12-C-6) 261 stronger Imaginary models can be illustrated as 21, 22, and 23 Two 3c–4e bonds should be formed to be coordinated by two waters or dimethyl ethers for each one, in which there are two positive charges and two orthogonal vacant 2p orbitals on the central carbon The two hydrogen (21), methyl (22), or phenyl (23) groups are connected to the sp carbon They are quasi stable by theoretical calculation and the structure and the carbon–oxygen bond energy are obtained H H O H O H H C H 21 H O H H 3C H 3C O O H H H3C O H3C CH3 CH3 O CH3 C O CH3 CH3 CH H C H 3C O H3 C O H 3C C CH3 O CH O CH3 CH3 22 23 As model compounds for experimental synthesis, compound 24 having two orthogonal anthracene skeletons is derived from and compound 25 bearing phenyloxymethyl arms at the 2,6-positions of a benzene ring (pincer ligand) is deduced from 15 Moreover, by dimethylation of thioxanthene (26) or xanthene allenes (28), it is expected to generate dicationic carbon species resembling 24b or 25b to build up hypervalent carbon compounds (12-C-6) of 27 or 29 Actually, 26 and 27 have been synthesized and their structures determined by X-ray analysis The thioxanthene skeleton of 27 is considerably strained, and the distances of the four C(allene)–O bonds are 2.641, 2.706, ˚ (av = 2.693 A) ˚ These distances are slightly larger 2.750, and 2.673 A ˚ than the C–O bond of (2.43, 2.45 A) ˚ but are not much longer ( = 0.25 A) ˚ and are almost equal to it In conclusion, it than that of 15 (av = 2.711 A) can be believed that there are two 3c–4e bonds in the C–O of 27, and 27 serves as the first example of a hexacoordinate hypervalent carbon compound (12-C-6) [10] On the basis of theoretical calculations, the 3c–4e bond of 27 is the weakest among 24, 25, 27, and 29 and the order of their bond energy is 25 > 24 > 29 > 27 The distance of the four C(allene)–O bonds of 25 is calculated as ˚ and the bond energy is 26.9 kcal/mol; the presence of a typical 3c–4e 2.484 A bond was clearly demonstrated by molecular orbital calculations [11] On the basis of these results, there is no doubt as to the presence of a hexacoordinate hypervalent carbon compound (12-C-6) On the other hand, the question still is: in compound 27 a carbodication is surrounded by and floating in the sea of electrons of the four oxygens and what kind of bonds are they? In case the fundamental ideas mentioned here to expand the valence of the main group elements are applied to elements of the third period and heavier, interesting development of chemistry can be expected 262 HYPERVALENT CARBON COMPOUNDS: CAN HEXAVALENT CARBON EXIST? +2 Me O O C O O Me Me Me O Me Me O O C C O O Me Me Me Me O O O Me Me 24a 24b 24c Hexa coordinate hypervalent carbon species Two vacant orbitals lie on the central sp carbon Positive charge lies in each benzene ring +2 MeC6H4 O O C O O MeC6H4 MeC6H4 C6H4Me O O C O O MeC6H4 MeC6H4 C6H4Me O C6H4Me O C O O MeC6H4 C6H4Me C6H4Me 25a 25b 25c Hexa coordinate hypervalent carbon species Two vacant orbitals lie on the central sp carbon Positive charge lies in each benzene ring Me Me S +2 Me O Me O MeX C S Me S O O C Me S O O Me Me Me O O Me 26 – 2X 27 Me +2 O Me O O C MeX O Me O O Me 28 Me Me O O O C O O Me Me Me O – 2X 29 REFERENCES (a) Musher JI Angew Chem Int Ed Engl 1969;8:54; (b) Akiba K.-y., editor Chemistry of hypervalent compounds Weinheim, Wiley-VCH; 1999 (a) Breslow R, Garratt S, Kaplan L, LaFollette D J Am Chem Soc 1968;90:4051; (b) Breslow R, Kaplan L, LaFollette D J Am Chem Soc 1968;90:4056 Hojo M, Ichi T, Shibato K J Org Chem 1985;50:1478 REFERENCES 263 (a) Basalay RJ, Martin JC J Am Chem Soc 1973;95:2565; (b) Martin JC, Basalay RJ J Am Chem Soc 1973;95:2572 (a) Martin JC Science 1983;221(4610): 509; (b) Forbus TR Jr, Martin JC J Am Chem Soc 1979;101:5057; (c) Forbus TR Jr, Martin JC Heteroatom Chem 1993;4: 113–128, 129; (d) Forbus TR Jr, Kahl JL, Faulkner LR, Martin JC Heteroatom Chem 1993;4:137 (a) Akiba K.-y,, Yamashita M, Yamamoto Y, Nagase S J Am Chem Soc 1999;121:10644; (b) Yamashita M, Yamamoto Y, Akiba K.-y., Hashizume D, Iwasaki F, Takagi N, Nagase S J Am Chem Soc 2005;127:4354; (c) Yamashita M, Yamamoto Y, Akiba K.-y., Nagase S Angew Chem Int Ed 2000;39:4055; (d) Yamashita M, Kamura K, Yamamoto Y, Akiba K.-y Chem Eur J 2002;8:2976 Akiba K.-y., Moriyama Y, Mizozoe M, Inohara H, Nishii T, Yamamoto Y, Minoura M, Hashizume D, Iwasaki F, Takagi N, Ishimura K, Nagase S J Am Chem Soc 2005;127:5893 Lee DY, Martin JC J Am Chem Soc 1984;106:5745 (a) Yamamoto Y, Akiba K.-y J Synth Org Chem Jpn 2004;62:1128; (b) Akiba K.-y., Yamamoto Y Heteroatom Chem 2007;18:161 10 Yamaguchi T, Yamamoto Y, Kinoshita D, Akiba K.-y., Zhang Y, Reed CA, Hashizume D, Iwasaki F J Am Chem Soc 2008;130:6894 11 (a) Kikuchi Y, Ishii M, Akiba K.-y., Nakai H Chem Phys Lett 2008;450:37 (b) Nakai H, Okoshi M, Atsumi T, Kikuchi Y, Akiba K.-y Bull Chem Soc Jpn 2011;84:505 NOTES 10 MAIN GROUP ELEMENT PORPHYRINS Porphyrin and its related compounds, such as hemoglobin (Fe(II) complex), chlorophyll (Mg(II) complex), and vitamin B12 (Co(III) complex), are important and widely present as biomolecules Central elements of these are transition metals; however, porphyrins bearing main group elements as the central atom are also known to have unique structures and characteristics [1] Porphyrin (1) is a planar 20-member ring, in which four pyrrole rings are connected with four one-carbon groups (–CH=) Porphyrin consists of 18π (4n + 2) aromatic system because carbon–carbon double bonds in two pyrrole rings (B, D) are not counted in the cyclic conjugated system Skeleton of porphyrin and its representative derivatives are illustrated in Fig N10.1 When two hydrogens in the core are substituted for another element, a variety of element porphyrins are obtained As main group element porphyrins, groups 1, 2, 13, 14, and 15 element porphyrins are known but groups 16, 17, 18 element porphyrins are not known [2] Group Derivatives: A lithium ion sits in the dianion core of porphyrin, and another one is coordinated with four tetrahydrofuran (THF) molecules and located outside the core as a counter ion Na+ and K+ are coordinated with two THF molecules, and they coordinate with two nitrogens of the core from above and below the molecular plane Organo Main Group Chemistry, First Edition Kin-ya Akiba © 2011 John Wiley & Sons, Inc Published 2011 by John Wiley & Sons, Inc 265 266 HYPERVALENT CARBON COMPOUNDS: CAN HEXAVALENT CARBON EXIST? A NH B N TTP: Tetraphenylporphyrin (phenyl groups: 5, 10, 15, 20) OEP: Octaethylporphyrin (ethyl groups: 2, 3, 7, 8, 12, 13, 17, 18) OETPP: Octaethyltetraphenylporphyrin (Ethyl groups: 2, 3, 7, 8, 12, 13, 17, 18; phenyl groups: 5, 10, 15, 20) 10 20 19 D 18 17 N HN 16 14 15 11 C 12 13 H2(Porphyrin) Figure N10.1 Structure of porphyrin and its derivatives Group Derivatives: Mg porphyrin is stable and has been investigated in detail in relation to chlorophyll Be, Ca, Sr, Ba porphyrins are unstable and are not well investigated Group 13 Derivatives: Boron is not contained in the core but binds with a nitrogen of two porphyrins and forms an–N–B(F)–O–B(F)–N–bridge Al, Ga, In, Tl porpyrins have been prepared Among them, Al porpyrins are effectively used as polymerization and carbon dioxide fixing catalysts by the Inoue and Aida group in Japan [3a,b] Group 14 Derivatives: Two oxidation states of two and four valences are known for each element Elements of higher oxidation states bear two axial Cl Ph N H2(TPP) SbCl3 Ph OMe N Sb N N Ph N R N (COBr)2 Sb N N Y OH a = Me, b) R = Et Y N R N N NuH Sb N N Y Br * H2(OEP)follows the same type of reactions as H2(TPP) to affords corresponding products Figure N10.2 N OH [(TPP)Sb(OMe)(OH)] R N N Sb N Ph (TPP)Sb(Cl) R3Al N H2O2 / MeOH N Sb N N Y Nu [(TPP)Sb(Me)(Nu)] Nu = (a) EtO and MeO (b) p-CH3C6H4S (c) PhCH2NH (d) PhC(O)O (e) t-BuOO (f) HOO (g) Me and Et Synthesis of hypervalent TPP and OEP derivatives of antimony 267 MAIN GROUP ELEMENT PORPHYRINS ligands Derivatives of Si(IV), Ge(IV), Sn(II), Sn(IV), Pb(II) are stable, but those of Si(II), Ge(II), Pb(IV) are unstable or unknown Group 15 Derivatives: Two oxidation states of three and five are known for each element Derivatives of P(III) are easily oxidized to those of P(V), and Bi(III) derivatives are known, but Bi(V) are not Derivatives of As were reported earlier; they were initially not examined properly but were properly prepared recently Their structures were determined by X-ray analysis [4] For antimony and phosphorus derivatives, those bearing carbon substituent(s) as axial ligand(s) were synthesized recently, and some of them are briefly mentioned here Et Et Cl R Et N PCl3 N Et N R3Al P N Et Et Et Et Et R R Et N RPCl2 N Et N DBU N P N Et N P Cl N N HCl N O 10 Et Et N R [(OEP)P(R)2] R = Me, Et Cl Et [(OEP)PCl2] H2(OEP) N P N Cl N N OH Et 9: R = Me, Et, Ph (COBr)2 R N R N N NuH P N N Br 11 Y N P N N Y Nu 12 [(OEP)P(R)(Nu)] Nu = (a) R (Me, Et) (b) OEt (c) NHBu (d) Cl (e) F Figure N10.3 Synthesis of hypervalent OEP derivatives of phosphorus Y 268 HYPERVALENT CARBON COMPOUNDS: CAN HEXAVALENT CARBON EXIST? Antimony(III) porphyrin (2) is obtained in high yield by the reaction of H2 (TPP) and antimony trichloride in the presence of 2,6-dimethylpyridine Unshared electron pair of is considerably reactive and gives Sb(V) derivative of [(TPP)Sb(OMe)(OH)]+ Y− (3) by treatment with hydrogen peroxide in methanol The methoxy group of is converted to alkyl groups with trialkylaluminums to give The hydroxyl group of is converted to the bromide (5) with oxalyl dibromide, and yields a variety of by nucleophilic substitution Compounds 3, 4, are stable thermally, and the structures determined by X-ray analysis to show their porphyrin skeletons are planar Their axial bonds are hypervalent, and compounds and are the first ones bearing carbon substituent(s) at axial position(s) [5] Compounds 6e and f are peroxides, and 6g is a dialkyl derivative Hydroperoxides of transition metal porphyrins are reactive and unstable to be isolated but compound 6f is isolable in high purity and used as an oxidant (Fig N10.2) Phosphorus is the smallest element that can be contained in the porphyrin core; hence, the core is not planar and is strained as ruffle shape, saddle shape, and so on Phosphorus porphyrins bearing carbon substituent(s) at axial position(s) were prepared for the first time recently [6] They (8, 9, 10, 12) are stable, and structures were determined by X-ray analysis Comparing the structure of 12, it is clearly seen that the P–N length decreases and the core becomes increasingly strained according to the increase in electron-withdrawing ability of axial substituent(s) Compound is deeply ruffled, and the hydroxyl group is strongly acidic (pH ≈ 7–8) Crystals of compound 10 are obtained by treating with NaOH or diazabicyclo undecene (DBU), and the skeleton is completely planar The fact means that acid–base equilibration takes place between and 10 under almost neutral conditions; thus, quite a large change of the shape of porphyrin occurs considerably rapidly at the ambient temperature This should be an interesting phenomenon as a biomolecule (Fig N10.3) REFERENCES Brothers PJ, Organoelement Chemistry of Main_Group Porphyrin Complexes (review) Adv Organomet Chem 2001;48:289 Yamamoto Y, Akiba K.-y Kikan Kagaksousetu 1998;34:93 (Japanese) (a) Inoue S, Aida T Kikan Kagaksousetu 1993;18:55; (b) Inoue S, Aida T Kikan Kagaksousetu 1994;23:160, (Japanese); (c) Sugimoto H, Aida T, Inoue S Bull Chem Soc Jpn 1995;68:1239 Yamamoto Y, Akiba K.-y J Organomet Chem 2000;611:200 Kadish KM, Autret M, Ou A, Akiba K.-y., Masumoto S, Wada R, Yamamoto Y Inorg Chem 1996;35:5564 Akiba K.-y., Nadano R, Satoh W, Yamamoto Y, Nagase S, Ou Z, Tan X, Kadish KM Inorg Cehm 2001;40:5553 INDEX acid–base equilibrium, 124, 268 acid–base reaction, 15 acidity, 160 of carboxylic acid, 7–10 substituent effect, 7–10 pKa of, active Zn(II)ate complex, 74 aldol reaction, 95, 128 alkalimetal phosphide, 114 alkaline hydrogen peroxide, 98 alkoxylation, 115 alkoxyphosphonium salt, 196 alkoxysulfonium salt, 165 alkyl thiol, 160, 162 alkylidenetriphenylphosphorane, 125 alkyllithiums, 64, 67 alkylpentafluorosilicate, 99 alkyltrifluorosilane, 98 allylsilanes, 94 aluminum compounds, 79–88 synthesis, 80–82 aluminum–carbon bond, 81 amination, 115 amino carbenes, 107 ammoniosilicate, 202 anomeric effect, 11–13 anti-apicophilic, 137 anti-apicophilic oxaphosphetane, 152 antibonding orbital, 170 anti-Markovnikov type, 85 antimony compounds, 143–146 ligand coupling reaction of, 227–237 antiparallel shift, 86 anti-periplanar bond, 12, 95 ap–ap coupling, 236 apical bond, 34, 233 apical entry–apical departure, 134–135 apical ligand, 226 apicophilicity, 37, 41–45, 132, 175 of carbon substituents, 41 Arbuzov reaction, 117–118 Arduengo carbene, 14, 106 aromatic compounds of group 14 elements, 222–223 Ar–Tol, 235–236 aryl sulfide, 163 arylselenenyl halide, 175 asymmetric reaction, 98, 123 asymmetric sulfoxides, 163 asymmetric yield, 71–72 ate complexes, 66, 103 atomic number, atrane, 202–208, See also silatrane Aufbau principle, 1–3, 23 Organo Main Group Chemistry, First Edition Kin-ya Akiba © 2011 John Wiley & Sons, Inc Published 2011 by John Wiley & Sons, Inc 269 270 INDEX azaphosphatrane, 203, 206 azatrane, 206–207 aziridine, 145 Bailar twist, 26, 39 Beckmann rearrangement, 47 bell-clapper rearrangement, 253 bending motion, 182 benzylpotassium, 65 benzyne, 199 Berry pseudorotation (BPR), 26, 42, 131–132, 137–138, 155, See also freezing BPR and its effect Bertrand carbene, 108 BINAP, 123 2,2 -bipyridyl, 240 bismuth compounds, 143–146 ligand coupling reaction of, 227–237 black phosphorus, 31 bond angle, 160 bond contraction, 217, 220 bond dissociation energy, 17 bond distance, 233 bond order, 83 bond switching, 174, 256 at carbon and boron, 254–259 borane, 80 borate anion, 85 borazine, 83 boron compounds, 79–88 synthesis, 80–82 boron–nitrogen bond, 258 bridging bond, 83 bromine compounds, 188–190 C-alkylation, 75 α-C-phenylation, 231 α-carbanion, 49 carbenes, 14, 197 amino carbenes, 107 Arduengo carbene, 106 Bertrand carbene, 108 and its complex, 105–108 singlet carbene, 105 triplet carbene, 105 carbon, 29 carborane super acid, 84 C-arylation, 230–231 catechol borane, 195 chair conformation, 12 chlorine compounds, 188–190 chlorosilanes, 92 cis-stilbene, 125 conrotatory direction, 59 copper compounds, 63–77 reactions, 68–77 structure, 66–68 synthesis, 64–66 C-phenylation, 230–232, 242 cross-coupling, 102 cumulated double bond, 217 D-dibenzoyltartaric acid, 119 α-D-glucose, 11 β-D-glucose, 11 dehydrogenating reagent, 170 deoxygenation, 115 deprotonation, 49–50, 69–72, 75 Desargues–Levi diagram, 43 Dess–Martin reagent, 196–197, 199 deuterium shift, 197 df elements, di(trimethylsilyl)methyl (Dis), 215 diacetoxyiodobenzene, 196 dialkyl alkylphosphonate, 128 dialkylcuprate, 76–77 diaryl iodonium salt, 241 diastereomers, 120, 164 1,3-diaxial repulsion, 12 diazonium salt (Schiemann reaction), 194 dibenzothiazocine, 208 dibismuthene, 216, 218 diborane, 80 dication, 210 dichlorosilane, 93 diequatorial positions, 136–137 diethyl ethylphosphonate, 117 diethylaminosulfur trifluoride (DAST), 193 dimer of carbenes, 220 2,6-dimesitylphenyl (Dmp), 218–219 dimethyl sulfoxide (DMSO), 165 1,2-dimethylaminocyclohexane, 129 dimethylmagnesium, dimethyloxosulfonium methylide, 168 dimethylsulfonium methylide, 168 dioxane dibromide, 188–190 diphenyliodane, 243 diphosphene, 214 diselenoacetal, 176 disilane, 93 disilene, 214, 219, 221 disilyne, 220 disproportionation, 101, 144 disrotatory direction, 59 dissociation equilibrium, 125 distibene, 216, 218 ditelluroacetal, 176 dithiane, 167 INDEX 1,5-dithiaoctane, 210 double bond rule, 213, 216–217 edge attack, 155–157 edge inversion, 45–46, 181–186 E-enolate, 70 eighteen-electron rule, 23–24 eight-member ring, 138 electrocyclic reaction, 57–61 electron, electron-donating ability, 257 electron-donating substituent, 87 electronegative substituent, 174 electronegativity, 6, 9, 17–18 Allred–Rochow, 18 Mulliken, 18 Pauling, 17 electronic configuration of an atom, 3–5 electron-withdrawing ability, 257, 268 electron-withdrawing substituent, 87 electrophilic hydroxylating reagent, 190 enol, 191 enol phosphate, 118 enolate anion, 69, 95 enthalpy-controlled reaction, 49 epoxide, 145 equatorial bond, 34 equatorial ligand, 226 1:1 equilibrium mixture, 173 ethoxycarbonylmethylenephosphorane, 125 ethylmagnesium bromide, face attack, 155–156 FAMSO, 168 first ionization energy, five-member cyclic phosphate, 131 five-member ring, 137 flash vacuum thermolysis (FVT), 234 fluorine compounds, 190–195 fluorine gas, 192 formal charge, 19–21 formal logical rule, 23 formylating reagent, 10 free radical chain reactions, 101 freezing BPR and its effect, 138–143 germabenzene, 222 1,2-glycol, 145 Grignard reagents, 65, 73 Schlenk equilibrium of, 68 group transfer polymerization, 99 H–D exchange reaction, 50 sulfonium salt, 51 271 H2 M, characteristics of, 161 1-halosilatrane, 203 Hammett equations, heteroatoms, 1–16 α-carbocation stabilization by resonance, 10–15 characteristics, 1–16 electronic configuration, 3–5 heteroatom effect, 26 scope, 1–16 stereoelectronic effect, 10–15 hexa(p-trifluoromethyl) tellurium, 248 hexachlorodisilane, 123 hexacoordinate compounds, 37, 40 hexacoordinate difluoroallylsilicate, 99 hexacoordinate hypervalent carbon species (12-C-6), 259–262 12-E-6, 210 hexamethyltellurium, 247–248 1,3,5-hexatriene systems, 60–61 hexavalent organotellurium compounds, 247–249 high-energy pass, 44 higher valent iodine, 199 highest occupied molecular orbital (HOMO), 46, 59 highly coordinate silicon species, 97 Horner reaction, 127 Hueckel molecular orbital (HMO), 57–61 of conjugate polyenes, 59 of 1,3,5-hexatriene with relative energy, symmetry, and node, 60 hydroalumination, 81 hydroboration, 80 hydrogen bond, 201 1-hydrosilatrane, 203 hydrosilanes, 92 hydrosilylation, 94 δ-hydroxyolefin, 97 hypervalence, 23–24 hypervalent bond, 208, 252 hypervalent bond energy, 175 hypervalent bond formation, 201–211 hypervalent compounds, 24, 31–33, 245, 251–262 dicoordinate, 34 effect of hypervalent bond, 33–45 hexacoordinate, 37, 40 pentacoordinate, 36 phosphorus, 32 silicon, 32 sulfur, 32 272 INDEX hypervalent compounds (Continued) tetracoordinate, 36–37 tricoordinate, 35 hypervalent organosulfur compounds, 170–175 reaction of, 170–175 structure, 170–175 hypervalent radical, 177 hypervalent S–N bond, 174 hypervalent species, 97, 102 icosahedral cage, 84 imidazol-2-ylidene, 106 imidazolium salt, 106 inductive effects, 7–8 inert gases, intramolecular isomerization, 44 inversion, 252 inversion configuration, 121, 123, 127, 155–158 inversion energy, 182 iodine compounds, 195–199 iodobenzene, 197 iodolactonization, 195 iodosobenzene, 196 isomerization, 44 ketene silyl acetal, 99 ketyl radical intermediate, 75 kinetic conditions, 69 kinetic protection, 215 lead compounds, 91–103 lead halide, 103 lead tetra (trifluoroacetate), 103 lead tetraacetate, 103 Lewis acids, coordination with, 15–16 ligand coupling, 87 ligand coupling reaction (LCR), 45–46, 225–245 of antimony compounds, 227–237 of bismuth compounds, 227–237 organoiodine compounds, 241–245 of phosphorus compounds, 227–237 selectivity of, 226–227 of selenium compounds, 237–241 of sulfur compounds, 237–241 theoretical investigation, 226–227 tellurium compounds, 237–241 ligand coupling reaction, 199 ligand exchange reaction (LER), 87, 234 lithium compounds, 63–77 reactions, 68–77 structure, 66–68 synthesis, 64–66 lithium dimethylcuprate, 68, 76–77 conjugate addition of, 76–77 lithium enolate, 102 lithium trifluoride, 33 lowest unoccupied molecular orbital (LUMO), 46, 59 magnesium compounds, 63–77 reactions, 68–77 structure, 66–68 synthesis, 64–66 main group element effect, 25–53, 166 description, 25–26 double bond group 14 elements, 29 group 15 elements, 29–31 main group elements characteristics, 1–16 df elements, electronic configuration, 3–5 fundamental properties of, 5–7 scope, 1–16 sp elements, unsaturated compounds of, 213–223 Markovnikov rule, 85, 188, 195 masked 1,3-dipole, 172 mass number, Meerwein reagent, 10, 15 memory effect, 236 metal exchange, 178 metal-hydrogen exchange, 65 metalloids, 1-methoxysilatrane, 203 methylaluminoxane (MAO), 88 methyllithium, 66 methylphenylpropylphosphine, 120 metylenetriphenylphosphorane, 124 Mitsunobu reaction, 196 mixed halogens, 191 molecular orbital calculations, 261 monomeric reagent (RMgX), 67 monopersulfuric acid, 160 morphorinosulfur trifluoride (MOST), 193 MT-sulfone, 168 mutarotation, 11 MX4 -type compounds, nucleophilic substitution of, stereochemistry, 155–158 N-bromosuccinimide (NBS), 189 neutrons, NF3 , inversion mechanism, 181–186 N-fluoropyridinium salt, 192 NH3 , inversion mechanism, 181–186 no bond resonance, 37 INDEX nonnucleophilic amides, 67 np orbital, 29 ns orbital, 29 N–Si bond, 203 nucleophilic reaction, 72–76 nucleophilic reaction, tertiary phosphine, 115–117 N-X-L designation, 32 O-alkylation, 75 O-arylation, 231–232 O-cis, 140–143 octahedron, 170 O–C–O bond, 255 octet rule, 23–24 olefin metathesis, 116 optically active aminoalcohol, 128 optically active olefin, 129 optically active phosphines synthesis of, 119–123 asymmetric reduction, 123 optically active sulfonium salt, 170 optically active tertiary phosphine, 120 orbital symmetry, 226 orbitals sign of, 1–3 wave function of, organoaluminums, 81–82 organoboranes, 80 organocuprates, 68 organohalogen compounds, 187–199 organo-hypervalent compounds, 152 organoiodine compounds, ligand coupling reaction of, 241–245 divalent organolead, 100 organolead compounds, 100–103 organophosphorus compounds, synthesis of, 113–114 organoselenium compounds, synthesis of, 176 organosilicons, 92 organosulfur compounds, See also hypervalent organosulfur compounds main group element effect, 166 reactions of, 166–170 synthesis of, 160–166 organotelluride, 177 organotellurium compounds, synthesis of, 176 organotin compounds, 100–103 ortho-lithiation, 64, 70–71 O-trans, 140–143 oxaphosphetane, 115, 125, 151, 152 oxidation number, 19–21 oxidative addition, 76, 100, 226 oxosulfonium salt, 165 273 Pauli exclusion principle, 34 pentaarylantimony, 233 pentaarylnictogens, 237 pentaaryltellurium anion, 247–249 pentacoordinate hypervalent carbon species (10-C-5), 36, 253–254 O–C–O bond, 255 pentamethylantimony, 131, 233 pentaphenylbismuth, 229 pentaphenylphosphorane, 131, 151, 152, 227 pentastanna[1.1.1]propellane, 221 pentavalent bismuth, 145, 229 pentavalent organoantimony, 144 pentavalent phosphorane, 131 pentavalent phosphorus, 151 periodic table, Perkow reaction, 118–119 Peterson reaction, 94 P–H phosphatrane, 204 phase-transfer catalyst, 162, 164 Ph–E+ , 211 phenoxyphosphorane, 228 phosphate hydrolysis, 131 phosphatrane, 203 phosphine, 113 phosphine-alkylene, 150 phosphine-imine, 150 phosphine oxide, 122 reduction of, stereochemistry, 122 phosphonate, 113 phosphonite, 113 phosphonium salts reactions, 115, 127, 131–138 phosphoranate anions, 40, 139 phosphoranes, 228 formation, 131–138 structure of, 34 phosphoranide anion, 139 phosphorus compounds, 112–113, See also optically active phosphines; organophosphorus compounds alkalimetal phosphide, 114 characteristic reactions, 112 inversion, 127 ligand coupling reaction of, 227–237 phosphonium, 127 phosphoric acid, 112 phosphorus ylide, 124 porphyrins, 268 retention, 127 stereochemistry, 121 tertiary phosphine, 113 tertiary phosphine oxide, 114 tertiary phosphine sulfide, 114 π -bond energy, 27–31, 214 274 INDEX phosphorus compounds (Continued) π -electrons, 222 π, π ∗ , 57–61 pinacolone, 46 porphyrins, 265–268 group derivatives, 265 group derivatives, 265 group 13 derivatives, 266 group 14 derivatives, 266 group 15 derivatives, 267 Mg porphyrin, 265 positional isomerization, 42, 234 potassium triiodie, 33 proatrane, 204 propagation step, 101 protons, pseudorotation, 45, 138–143 Berry pseudorotation (BPR), 42 Pummerer rearrangement, 167 pyridine hydrobromide dibromide, 188 pyridinium hydrogen fluoride, 193 2-pyridyl vinyl sulfoxide, 240 pyrolysis, 227 quasi-atrane, 204 radical reaction, 189 Ramberg–Baeckland reaction, 167 Ramirez compound, 119 rate of inversion, 184 reaction coefficient, red phosphorus, 31 reductive elimination, 76, 87, 226 retention configuration, 121, 155–158 ring strain, 137 Rochow method, 92 rodenticide, 202 ruffle shape, 268 sarbarsane 606, 213 Schiemann reaction, 190 Schlenk equilibrium, 67 of Grignard reagent, 68 S–C–S hypervalent bond, 254 second ionization energy, selenium compounds, 175–178 ligand coupling reaction of, 237–241 selenoxide, 175, 176 S–E–S bond, 210 σ , σ ∗ , 57–61 σπ P −O , 141 σ -π conjugation, 48 σX−C effect, 46–48 ∗ effect, 48–53 σX−C [2,3] sigmatropy, 169–170 silabenzene, 222–223 silacubane, 93 silanol, 93 silatrane, 202–208 silicate, 98 silicon compounds, 30, 91–103 silicon–carbon bond, 92 silicon–chlorine bond, 92–93 siloxane, 93 silyl anion, 93–94 silyl enol ethers, 69, 92, 243 silyl triflate, 92 silylbenzene, 96 silylstannane, 93 single bond energy, 27–31 singlet, 14 singlet carbene, 105 six-member ring, 136 six-member transition state, 73 S–N interaction, 208 SN reaction, 137, 252 sodium borohydride (NaBH4 ), 80 softer carbanion, 75 sp elements, sp2 configuration of sulfur, 209 stabilization energy, 51–52 Staudinger, dreams of, 149–152 stereoelectronic effect, 10–15 mutarotation, 11 steric protection, 215 stibonium salt, 144 substituent constant, substituent effect, 7–10 meta, ortho–para, substituted iodanes, 197 substitution at silicon, 135 sulfinic acid, 164 sulfone, 164 sulfonium salt, 165, 255 sulfoxide, 163, 237–238 sulfur, 31 sulfur compounds, 159–178, See also organosulfur compounds ligand coupling reaction of, 237–241 Suzuki–Miyaura coupling, 86 catalytic cycle of, 87 Swern oxidation, 167 S-ylide, 169 symmetry-allowed, 226 symmetry-forbidden, 226 INDEX t-butyltetramethylguanidine, 230 tellurium compounds, 175–178 ligand coupling reaction of, 237–241 tertiary phosphine oxide, 114, 121 tertiary phosphine sulfide, 114 tertiary phosphines, 113, 115 with bulky substituent, 116 nucleophilic reactions of, 115–117 tetraarylchalcogens, 237 tetrabutylammonium fluoride (TBAF), 95, 193–194 tetracoordinate hypervalent compounds, 36–38 tetramer of methyllithium, 66 tetramethylethylenediamine (TMEDA), 67 tetramethyltellurium, 240, 247 thermodynamic conditions, 69, 215 thermolysis, 228, 233 thiathiophthenes, 37, 170, 172 thiols, 161 thiophenol, 162 three-center four-electron bond, 24 3c–4e bond, 182, 185, 201, 211, 252, 257, 258 4-H-2, 202 molecular orbitals of, 35 structure, 33–40 three-center rearrangement, 118–119 3-center 2-electron bond, 82–83 tin compounds, 91–103 tin enolate, 102 tin hydride, 101 tin radical, 102 Tol–Tol, 235–236 transannular interaction, 208–211 between heteroatoms, 209 transition-metal complexes, 123 transition metals, 23, 115 transition state of SN 2, 254 transmetallation, 65, 87 trans-stilbene, 125 tributylmethoxytin, 102 trichlorosilane, 93 tricoordinate hypervalent compounds, 35 tricyclohexylphosphine, 115 trigonal bipyramids, 170, 209, 233 trimethyl oxosulfonium salt, 165 275 triplet, 14 triplet carbene, 105 2,4,6-tris[(bistrimethylsilyl)methyl]phenyl (Tbt), 215–216 tris(trimethylsilyl)methyl (Tsi), 215 trisilaallene, 220 2,4,6-tri-t-butylphenyl group (Mesr ), 215 T-shape compounds, 37, 177, 181 ultrasonic wave, 64 unsaturated compounds of main group elements, 213–223 group 14 elements of third period and heavier, 219–222 group 15 elements of third period and heavier, 215–219 unshared electron pair, 13, 37 vacant p orbital, 182 vertex inversion, 46, 181–186 Vilsmeier reagent, 10 vinyl iodide, 195 vinylidene carbene, 146 vinyliodane, 198, 242 vinyllithiums, 237 vinylpentafluorosilicate, 99 vinyltetraphenylphosphorane, 229 Wadsworth–Emmons reaction, 118, 128 white phosphorus, 30 Wittig reactions, 94, 125–126, 145, 149–152 xenon difluoride, 192 X–F reagent, 190 X–P–N, 209 X–S–N, 209 yellow phosphorus, 31 ylide reaction, 123–130 ylide structure, 207 ylides, 151 Z-enolate, 70 Ziegler–Natta catalyst, 88 zirconium metallocene, 88 zwitter ion, 118, 125 ... Organo- main- group chemistry (organic chemistry of main group elements) is a branch of organic chemistry dealing with structures, syntheses, and reactions of compounds bearing a carbon main group. .. reaction of main group element compounds This book, Organo Main Group Chemistry, consists of 12 chapters and 10 notes Chapters 1–8 describe the fundamental and basic organic chemistry of main group. .. Thus, according to the atomic Organo Main Group Chemistry, First Edition Kin-ya Akiba © 2011 John Wiley & Sons, Inc Published 2011 by John Wiley & Sons, Inc MAIN GROUP ELEMENTS AND HETEROATOMS: