Recent Developments in Carbocation and Onium Ion Chemistry (Acs Symposium Series 965)

538 Pages·2007·19.46 MB·English

by  Kenneth Laali

Recent Developments in
Carbocation and Onium Ion
Chemistry

In Recent Developments in Carbocation and Onium Ion Chemistry; Laali, K.;
ACS Symposium Series; American Chemical Society: Washington, DC, 2007.
In Recent Developments in Carbocation and Onium Ion Chemistry; Laali, K.;
ACS Symposium Series; American Chemical Society: Washington, DC, 2007.
ACS SYMPOSIUM SERIES 965
Recent Developments in
Carbocation and Onium Ion
Chemistry
Kenneth K. Laali, Editor
Kent State University

American Chemical Society, Washington, DC
In Recent Developments in Carbocation and Onium Ion Chemistry; Laali, K.;
ACS Symposium Series; American Chemical Society: Washington, DC, 2007.
Library of Congress Cataloging-in-Publication Data
Recent developments in carbocation and onium ion chemistry / Kenneth K.
Laali, editor.
p. cm.—(ACS symposium series ; 965)
Includes bibliographical references and index.
ISBN 13: 978-0-8412-7414-3 (alk. paper)
ISBN 10: 0-8412-7414-2 (alk. paper)
1. Carbocations. 2. Onium ions
I. Laali, Kenneth K.
QD305.C3R43 2007
541'.372—dc22
2006052660
The paper used in this publication meets the minimum requirements of
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In Recent Developments in Carbocation and Onium Ion Chemistry; Laali, K.;
ACS Symposium Series; American Chemical Society: Washington, DC, 2007.
Foreword
The volume is a valuable contribution to all chemists inter
ested in the significant and broad area covering some of the most
important reaction intermediates and their related chemistry. The
editor and contributors are to be congratulated for their effort and
valuable contribution.
George A Olah
USC Loker Institute

In Recent Developments in Carbocation and Onium Ion Chemistry; Laali, K.;
ACS Symposium Series; American Chemical Society: Washington, DC, 2007.
Contents

Preface
Kenneth K. Laali xi-xiii

1 Experimental and Computational NMR Spectroscopic Investigation of Silyl-Substituted
Carbocations
Hans-Ullrich Siehl 1-31

2 Super-Stabilization of π-Conjugated Cations by Annelation to Bicyclic Frameworks
Koichi Komatsu 32-50

3 Unusually Stable Vinyl Cations
Thomas Müller, Dominik Margraf, Yvonne Syha, Hamid Reza Nasiri, Christian
Kaiser, Rita Maier, Bettine Boltre, Mark Juhasz, and Christopher A. Reed 51-67

4 Vinyl Iodonium Salts as Precursors to Vinyl Cations
Tadashi Okuyama and Morifumi Fujita 68-87

5 Generation of Alkylideneallyl Cations from Alkylidenecyclopropanone Acetals:
Selectivity of Reaction with Nucleophiles
Morifumi Fujita and Tadashi Okuyama 88-105

6 Conformational Studies of Cyclobutylmethyl Cations
V. Prakash Reddy, G. K. Surya Prakash, and Golam Rasul 106-117

7 Persistent Organic Cationic Complexes: Structure and Reactivity
Gennady I. Borodkin and Vyacheslav G. Shubin 118-143

8 Activation of Electrophilic Sites by Adjacent Cationic Groups
Douglas A. Klumpp 144-159

9 Stabilized Carbocations as Redox Active Chromophores: Preparation of Electrochromic
Materials Using Stabilized Carbocations
Shunji Ito, Koji Akimoto, and Noboru Morita 160-183

10 Cation Pool Method and Cation Flow Method
Jun-ichi Yoshida 131-138

11 Fluorenylidene and Indenylidene Dications: Insights about Antiaromaticity
Nancy S. Mills 210-233

12 Generation, Stability, and Reactions of Alkylated Fullerene Cations
Toshikazu Kitagawa 234-253
13 Carbocations on Surfaces: Formation of Bicyclobutonium Cation via Ionization of
Cyclopropylcarbinyl Chloride over NaY Zeolite
Marcelo Franco, Nilton Rosenbach, Jr., W. Bruce Kover, and Claudio J. A. Mota
254-267

14 MO Calculations Involving µ-Hydrido Cation Intermediates Relevant to the Heptane to
Toluene Dehydrocyclization Reaction
Ted S. Sorensen and Esther C. F. Yang 268-296

15 Theoretical Studies on Structure and Dynamics of Carbonium Ions
Pierre M. Esteves, Felipe P. Fleming, and André G. H. Barbosa 297-328

16 Quantum Chemical Studies of Carbocations from Oxidized Metabolites of Aza-
Polycyclic Aromatic Hydrocarbons
Gabriela L. Borosky and Kenneth K. Laali 329-363

17 How Does Carbocation Stability Control the Beckmann Rearrangement Reaction?
Salai C. Ammal and Hiroshi Yamataka 364-374

18 Solvent Effects on the Chemistry of Bromonium and β-Bromocarbenium Ions as Reactive
Intermediates
Cinzia Chiappe 375-393

19 Syntheses of the CFY + (Y = Cl, Br) and CX + (X = Cl, Br, OTeF ) Cations Employing
2 3 5
the Noble-Gas Oxidant, XeOTeF +Sb(OTeF ) –
5 5 6
Hélène P. A. Mercier, Matthew D. Moran, and Gary J. Schrobilgen 394-427

20 Organoxenonium Salts: Synthesis by "Xenodeborylation", Reactivities, and NMR
Spectroscopic Properties
H.-J. Frohn and V. V. Bardin 428-457

21 Halogen Transfer Reactions from bis-Amino Halonium Ions to Acceptor Olefins:
Mechanism and Strategies for Chiral Halogenation
R. Stan Brown, Alexei A. Neverov, C. Tony Liu, and Christopher I. Maxwell 458-476

22 Synthesis of Phosphonium Salts by Metal-Catalyzed Addition Reaction
Mieko Arisawa and Masahiko Yamaguchi 477-492

Indexes

Author Index 495

Subject Index 497-528
Preface
In December of 2005, I organized a symposium entitled Recent
Developments in Carbocation and Onium Ion Chemistry at Pacifichem
in Hawaii, with Professors Ken Takeuchi (Kyoto University) and
Andrew Bennet (Simon Fraser) acting as coorganizers from Japan and
Canada, respectively. Twenty-four invited talks and twenty-two posters
were presented. The symposium brought together an impressive group of
leading experts and active researchers in the field, covering a broad
spectrum of structural/mechanistic, synthetic/preparative, and theoreti­
cal/computational aspects, as well as creating an exciting and dynamic
forum for highlighting current focus areas and trends.
Inspired by the success of the symposium, I subsequently agreed
to take on editorship of this volume. Fortunately, the majority of the
invited speakers at Pacifichem were able to participate in this project. In
addition, I invited several other internationally recognized researchers
who could not participate in the Hawaii symposium to also join the
project, bringing the total number of contributions to 22 chapters.
Chapter 1 by H.-U. Siehl discusses parallel stable ion NMR
spectroscopic and computational studies on various classes of silyl-
substituted carbocations. Chapter 2 by K. Komatsu focuses on unusually
stable π-conjugated carbocations that are formed as a result of annelation
to bicyclic frameworks.
The focus of Chapters 3 and 4 is on vinyl cations. In Chapter 3,
T. Müller et al. discuss the preparation, isolation, and characterization of
unusually stable vinyl cations; whereas Chapter 4 by T. Okuyama and
M. Fujita describes the generation and reactions of vinyl cations formed
via solvolysis of vinyl iodonium salts.
Chapter 5 by M. Fujita and T. Okuyama examines the ring-
opening reactions of alkylidenecyclopropanone acetals for solvolytic
generation and trapping of alkylideneallyl cations (resonance hybrids of
1-vinyl-substituted vinyl cations). In Chapter 6 by V. P. Reddy et al.
stable ion and computational studies of cyclobutylmethyl cations are
discussed. In Chapter 7, G. I. Borodkin and V. G. Shubin discuss and
xi
In Recent Developments in Carbocation and Onium Ion Chemistry; Laali, K.;
ACS Symposium Series; American Chemical Society: Washington, DC, 2007.
summarize more recent results from their laboratory on the NMR studies
of long-lived carbocations and nitrosonium π-complexes.
Changing the emphasis to synthetic chemistry in superacid
media, in Chapter 8, D. Klumpp examines the chemistry of dicationic
electrophiles, demonstrating their enhanced reactivity via heteroatom
protonation. In Chapter 9, S. Ito et al. explore the potential utility of
stabilized carbocations for designing redox-active chromophores.
Focusing on the synthetic/preparative aspects, in Chapter 10 by
J-i. Yoshida, novel approaches to generation of N-acyliminium and
alkoxycarbenium ions are presented and their synthetic applications are
discussed.
In Chapter 11 (the only chapter in the volume that focuses on
persistent oxidation dications), N. S. Mills discusses the fluorenylidene
dications and their antiaromatic character.
Recent progress in preparation and study of alkylated fullerene
cations RC + and RC + as long-lived species are examined by T.
60 70
Kitagawa in Chapter 12. Chapter 13 by C. J. A. Mota and co-workers
examines the formation of the bicyclobutonium cation via
cyclopropylcarbinyl chloride over solid acid catalysts.
The focus of the next four chapters (Chapters 14-17) is mainly
on the theoretical/computational aspects. Chapter 14 by T. S. Sorensen
and E. C. F. Yang examines the involvement of μ-hydrido cation
intermediates in the context of the industrially important heptane to
toluene dehydrocyclization process. Chapter 15 by P. M. Esteves et al. is
devoted to theoretical studies of carbonium ions. Chapter 16 by G. L.
Borosky and Κ. K. Laali presents a computational study on aza-PAH
carbocations as models for the oxidized metabolites of Aza-PAHs.
Chapter 17 by S. C. Ammal and H. Yamataka examines the borderline
Beckmann rearrangement-fragmentation mechanism and explores the
influence of carbocation stability on the reaction mechanism.
Chapter 18 by C. Chiappe focuses on the mechanism of
bromination of alkenes, exploring the role of solvent on the formation of
cyclic bromonium ion versus β-bromocarbernium ion, as key inter­
mediates. In Chapter 19, H. P. A. Mercier et al. discuss the utility of a
novel class of noble-gas onium salts as oxidants for generation and
isolation of various trihalomethyl cation salts.
The remaining three chapters (Chapters 20-22) concentrate fully
on onium ion chemistry. In Chapter 20, H.-J. Frohn and V. V. Bardin
describe synthesis and multi-nuclear NMR studies of organoxenonium
salts. Chapter 21 by R. S. Brown et al. focuses on the synthesis of chiral
xii
In Recent Developments in Carbocation and Onium Ion Chemistry; Laali, K.;
ACS Symposium Series; American Chemical Society: Washington, DC, 2007.