Organic Reactions, Volume 106 E-Book
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- Herausgeber: John Wiley & Sons
- Kategorie: Wissenschaft und neue Technologien
- Serie: Organic Reactions
- Sprache: Englisch
The 106th volume in this series for organic chemists in academia and industry presents critical discussions of the following widely used organic reactions: ALKENE CROSS-METATHESIS REACTIONS Karol Grela, Anna Kajetanowicz, Anna Szadkowska, and Justyna Czaban-Jozwiak THE CATALYTIC ENANTIOSELECTIVE STETTER REACTION Darrin M. Flanigan, Kerem E. Ozboya, Subhash D. Tanpure, Alberto Mu?oz, Paul R. Blakemore, and Tomislav Rovis
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Seitenzahl: 448
Veröffentlichungsjahr: 2021
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Table of Contents
Cover
Title Page
Copyright
INTRODUCTION TO THE SERIES BY ROGER ADAMS, 1942
INTRODUCTION TO THE SERIES BY SCOTT E. DENMARK, 2008
PREFACE TO VOLUME 106
CHAPTER 1: ALKENE CROSS‐METATHESIS REACTIONS
ACKNOWLEDGMENTS
INTRODUCTION
MECHANISM AND STEREOCHEMISTRY
SCOPE AND LIMITATIONS
APPLICATIONS TO SYNTHESIS
COMPARISON WITH OTHER METHODS
EXPERIMENTAL CONDITIONS
EXPERIMENTAL PROCEDURES
TABULAR SURVEY
REFERENCES
Chapter 2: THE CATALYTIC ENANTIOSELECTIVE STETTER REACTION
ACKNOWLEDGMENTS
INTRODUCTION
MECHANISM AND STEREOCHEMISTRY
SCOPE AND LIMITATIONS
APPLICATIONS TO SYNTHESIS
COMPARISON WITH OTHER METHODS
EXPERIMENTAL CONDITIONS
EXPERIMENTAL PROCEDURES
TABULAR SURVEY
REFERENCES
CUMULATIVE CHAPTER TITLES BY VOLUME
Volume 1 (1942)
Volume 2 (1944)
Volume 3 (1946)
Volume 4 (1948)
Volume 5 (1949)
Volume 6 (1951)
Volume 7 (1953)
Volume 8 (1954)
Volume 9 (1957)
Volume 10 (1959)
Volume 11 (1960)
Volume 12 (1962)
Volume 13 (1963)
Volume 14 (1965)
Volume 15 (1967)
Volume 16 (1968)
Volume 17 (1969)
Volume 18 (1970)
Volume 19 (1972)
Volume 20 (1973)
Volume 21 (1974)
Volume 22 (1975)
Volume 23 (1976)
Volume 24 (1976)
Volume 25 (1977)
Volume 26 (1979)
Volume 27 (1982)
Volume 28 (1982)
Volume 29 (1983)
Volume 30 (1984)
Volume 31 (1984)
Volume 32 (1984)
Volume 33 (1985)
Volume 34 (1985)
Volume 35 (1988)
Volume 36 (1988)
Volume 37 (1989)
Volume 38 (1990)
Volume 39 (1990)
Volume 40 (1991)
Volume 41 (1992)
Volume 42 (1992)
Volume 43 (1993)
Volume 44 (1993)
Volume 45 (1994)
Volume 46 (1994)
Volume 47 (1995)
Volume 48 (1995)
Volume 49 (1997)
Volume 50 (1997)
Volume 51 (1997)
Volume 52 (1998)
Volume 53 (1998)
Volume 54 (1999)
Volume 55 (1999)
Volume 56 (2000)
Volume 57 (2001)
Volume 58 (2001)
Volume 59 (2001)
Volume 60 (2002)
Volume 61 (2002)
Volume 62 (2003)
Volume 63 (2004)
Volume 64 (2004)
Volume 65 (2005)
Volume 66 (2005)
Volume 67 (2006)
Volume 68 (2007)
Volume 69 (2007)
Volume 70 (2008)
Volume 71 (2008)
Volume 72 (2008)
Volume 73 (2008)
Volume 74 (2009)
Volume 75 (2011)
Volume 76 (2012)
Volume 77 (2012)
Volume 78 (2012)
Volume 79 (2013)
Volume 80 (2013)
Volume 81 (2013)
Volume 82 (2013)
Volume 83 (2014)
Volume 84 (2014)
Volume 85 (2014)
Volume 86 (2015)
Volume 87 (2015)
Volume 88 (2015)
Volume 89 (2015)
Volume 90 (2016)
Volume 91 (2016)
Volume 92 (2016–2017)
Volume 93 (2017)
Volume 94 (2017)
Volume 95 (2018)
Volume 96 (2018)
Volume 97 (2019)
Volume 98 (2019)
Volume 99 (2019)
Volume 100 (2019)
Volume 101 (2020)
Volume 102 (2020)
Volume 103 (2020)
Volume 104 (2020)
Volume 105 (2021)
AUTHOR INDEX, VOLUMES 1‐106
CHAPTER AND TOPIC INDEX, VOLUMES 1‐106
End User License Agreement
List of Tables
Chapter 1
Table A Alkene Types for Selective Cross‐Metathesis (as defined in 2003 by Gr...
Table B Rules for Selectivity in CM.
List of Illustrations
Chapter 1
Scheme 1
Scheme 2
Scheme 3
Figure 1 Grubbs (
Ru‐1
,
Ru‐4
), Hoveyda–Grubbs (
Ru‐2
,
Ru‐5
...
Scheme 4
Scheme 5
Scheme 6
Scheme 7
Figure 2 . Representative monoalkoxide pyrrolide (MAP) molybdenum and tungste...
Scheme 8
Figure 3 (
Z
)‐Selective, ruthenium-based olefin metathesis catalysts.
Scheme 9
Scheme 10
Figure 4 Chiral molybdenum-based complexes.
Figure 5 Ruthenium complexes with
C
2
-symmetric NHC ligands.
Figure 6 Ruthenium complexes with
C
1
-symmetric NHC ligands.
Scheme 11
Scheme 12
Scheme 13
Scheme 14
Scheme 15
Figure 7 Analogues of the Hoveyda–Grubbs catalyst.
Figure 8 Selected molybdenum‐based complexes used in metathesis.
Figure 9 Valuable intermediates that can be derived from ethenolysis product...
Scheme 16
Scheme 17
Scheme 18
Scheme 19
Scheme 20
Scheme 21
Scheme 22
Scheme 23
Scheme 24
Scheme 25
Scheme 26
Scheme 27
Scheme 28
Scheme 29
Scheme 30
Scheme 31
Scheme 32
Scheme 33
Scheme 34
Scheme 35
Scheme 36
Scheme 37
Scheme 38
Scheme 39
Scheme 40
Scheme 41
Scheme 42
Figure 10 Structure of the chelate that forms in the absence of a Lewis acid...
Scheme 43
Scheme 44
Scheme 45
Scheme 46
Scheme 47
Scheme 48
Scheme 49
Scheme 50
Scheme 51
Scheme 52
Scheme 53
Scheme 54
Scheme 55
Scheme 56
Scheme 57
Scheme 58
Scheme 59
Scheme 60
Scheme 61
Scheme 62
Scheme 63
Scheme 64
Scheme 65
Scheme 66
Scheme 67
Scheme 68
Scheme 69
Scheme 70
Scheme 71
Scheme 72
Scheme 73
Scheme 74
Scheme 75
Scheme 76
Scheme 77
Scheme 78
Scheme 79
Scheme 80
Scheme 81
Scheme 82
Scheme 83
Scheme 84
Scheme 85
Scheme 86
Scheme 87
Scheme 88
Scheme 89
Scheme 90
Scheme 91
Scheme 92
Scheme 93
Scheme 94
Scheme 95
Scheme 96
Scheme 97
Scheme 98
Scheme 99
Scheme 100
Scheme 101
Scheme 102
Chapter 2
Scheme 1
Scheme 2
Figure 1 Experimentally determined pK
a
data (H
2
O) for a selection of triazol...
Scheme 3
Scheme 4
Scheme 5
Scheme 6
Scheme 7
Scheme 8
Scheme 9
Scheme 10
Figure 2 Putative mediation of 1,2-proton transfer by catechol.
Scheme 11
Scheme 12
Scheme 13
Scheme 14
Scheme 15
Scheme 16
Figure 3 Calculated steric and electronic effects on enaminol geometry [B3LY...
Scheme 17
Scheme 18
Scheme 19
Scheme 20
Scheme 21
Scheme 22
Scheme 23
Scheme 24
Scheme 25
Scheme 26
Scheme 27
Scheme 28
Scheme 29
Scheme 30
Scheme 31
Scheme 32
Scheme 33
Scheme 34
Scheme 35
Scheme 36
Scheme 37
Scheme 38
Scheme 39
Scheme 40
Scheme 41
Scheme 42
Scheme 43
Scheme 44
Scheme 45
Scheme 46
Scheme 47
Scheme 48
Scheme 49
Scheme 50
Scheme 51
Scheme 52
Scheme 53
Scheme 54
Scheme 55
Scheme 56
Scheme 57
Scheme 58
Scheme 59
Scheme 60
Scheme 61
Scheme 62
Scheme 63
Scheme 64
Scheme 65
Guide
Cover
Table of Contents
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FORMER MEMBERS OF THE BOARD OF EDITORS AND DIRECTORS
JEFFREY
AUBÉ
LAURA
KIESSLING
JOHN
E.
BALDWIN
MARISA
C.
KOZLOWSKI
PETER
BEAK
STEVEN
V.
LEY
DALE
L.
BOGER
JAMES
A.
MARSHALL
JIN
K.
CHA
MICHAEL
J.
MARTINELLI
ANDRÉ
B.
CHARETTE
STUART
W.
MC
COMBIE
ENGELBERT
CIGANEK
SCOTT
J.
MILLER
DENNIS
CURRAN
JOHN
MONTGOMERY
SAMUEL
DANISHEFSKY
LARRY
E.
OVERMAN
HUW
M. L.
DAVIES
T. V.
RAJANBABU
SCOTT
E.
DENMARK
JAMES
H.
RIGBY
VICTOR
FARINA
WILLIAM
R.
ROUSH
PAUL
FELDMAN
TOMISLAV
ROVIS
JOHN
FRIED
SCOTT
D.
RYCHNOVSKY
JACQUELYN
GERVAY
‐
HAGUE
MARTIN
SEMMELHACK
STEPHEN
HANESSIAN
CHARLES
SIH
LOUIS
HEGEDUS
AMOS
B.
SMITH
, III
PAUL
J.
HERGENROTHER
BARRY
M.
TROST
JEFFREY
S.
JOHNSON
PETER
WIPF
ROBERT
C.
KELLY
FORMER MEMBERS OF THE BOARD NOW DECEASED
ROGER
ADAMS
HERBERT
O.
HOUSE
HOMER
ADKINS
JOHN
R.
JOHNSON
WERNER
E.
BACHMANN
ROBERT
M.
JOYCE
ROBERT
BITTMAN
ANDREW
S.
KENDE
A. H.
BLATT
WILLY
LEIMGRUBER
VIRGIL
BOEKELHEIDE
FRANK
C.
MC
GREW
GEORGE
A.
BOSWELL
,
JR
.
BLAINE
C.
MC
KUSICK
THEODORE
L.
CAIRNS
JERROLD
MEINWALD
ARTHUR
C.
COPE
CARL
NIEMANN
DONALD
J.
CRAM
LEO
A.
PAQUETTE
DAVID
Y.
CURTIN
GARY
H.
POSNER
WILLIAM
G.
DAUBEN
HANS
J.
REICH
LOUIS
F.
FIESER
HAROLD
R.
SNYDER
HEINZ
W.
GSCHWEND
MILÁN
USKOKOVIC
RICHARD
F.
HECK
BORIS
WEINSTEIN
RALPH
F.
HIRSCHMANN
JAMES
D.
WHITE
Organic Reactions
VOLUME 106
EDITORIAL BOARD
P. ANDREWEVANS, Editor‐in‐Chief
STEVEN M. WEINREB, Executive Editor
DAVID
B.
BERKOWITZ
JEFFREY
N.
JOHNSTON
PAUL
R.
BLAKEMORE
ALBERT
PADWA
REBECCA
L.
GRANGE
JENNIFER
M.
SCHOMAKER
DENNIS
G.
HALL
KEVIN
H.
SHAUGHNESSY
DONNA
M.
HURYN
CHRISTOPHER
D.
VANDERWAL
JEFFREY
B.
JOHNSON
MARY
P.
WATSON
BARRY B. SNIDER, Secretary
JEFFERY B. PRESS, Treasurer
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ASSOCIATE EDITORS
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JUSTYNACZABAN‐JÓŹWIAK
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KAROLGRELA
ANNAKAJETANOWICZ
ALBERTOMUÑOZ
KAREM E. OZBOYA
TOMISLAVROVIS
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INTRODUCTION TO THE SERIES BY ROGER ADAMS, 1942
In the course of nearly every program of research in organic chemistry, the investigator finds it necessary to use several of the better‐known synthetic reactions. To discover the optimum conditions for the application of even the most familiar one to a compound not previously subjected to the reaction often requires an extensive search of the literature; even then a series of experiments may be necessary. When the results of the investigation are published, the synthesis, which may have required months of work, is usually described without comment. The background of knowledge and experience gained in the literature search and experimentation is thus lost to those who subsequently have occasion to apply the general method. The student of preparative organic chemistry faces similar difficulties. The textbooks and laboratory manuals furnish numerous examples of the application of various syntheses, but only rarely do they convey an accurate conception of the scope and usefulness of the processes.
For many years American organic chemists have discussed these problems. The plan of compiling critical discussions of the more important reactions thus was evolved. The volumes of Organic Reactions are collections of chapters each devoted to a single reaction, or a definite phase of a reaction, of wide applicability. The authors have had experience with the processes surveyed. The subjects are presented from the preparative viewpoint, and particular attention is given to limitations, interfering influences, effects of structure, and the selection of experimental techniques. Each chapter includes several detailed procedures illustrating the significant modifications of the method. Most of these procedures have been found satisfactory by the author or one of the editors, but unlike those in Organic Syntheses, they have not been subjected to careful testing in two or more laboratories. Each chapter contains tables that include all the examples of the reaction under consideration that the author has been able to find. It is inevitable, however, that in the search of the literature some examples will be missed, especially when the reaction is used as one step in an extended synthesis. Nevertheless, the investigator will be able to use the tables and their accompanying bibliographies in place of most or all of the literature search so often required. Because of the systematic arrangement of the material in the chapters and the entries in the tables, users of the books will be able to find information desired by reference to the table of contents of the appropriate chapter. In the interest of economy, the entries in the indices have been kept to a minimum, and, in particular, the compounds listed in the tables are not repeated in the indices.
The success of this publication, which will appear periodically, depends upon the cooperation of organic chemists and their willingness to devote time and effort to the preparation of the chapters. They have manifested their interest already by the almost unanimous acceptance of invitations to contribute to the work. The editors will welcome their continued interest and their suggestions for improvements in Organic Reactions.
INTRODUCTION TO THE SERIES BY SCOTT E. DENMARK, 2008
In the intervening years since “The Chief” wrote this introduction to the second of his publishing creations, much in the world of chemistry has changed. In particular, the last decade has witnessed a revolution in the generation, dissemination, and availability of the chemical literature with the advent of electronic publication and abstracting services. Although the exponential growth in the chemical literature was one of the motivations for the creation of Organic Reactions, Adams could never have anticipated the impact of electronic access to the literature. Yet, as often happens with visionary advances, the value of this critical resource is now even greater than at its inception.
From 1942 to the 1980's the challenge that Organic Reactions successfully addressed was the difficulty in compiling an authoritative summary of a preparatively useful organic reaction from the primary literature. Practitioners interested in executing such a reaction (or simply learning about the features, advantages, and limitations of this process) would have a valuable resource to guide their experimentation. As abstracting services, in particular Chemical Abstracts and later Beilstein, entered the electronic age, the challenge for the practitioner was no longer to locate all of the literature on the subject. However, Organic Reactions chapters are much more than a surfeit of primary references; they constitute a distillation of this avalanche of information into the knowledge needed to correctly implement a reaction. It is in this capacity, namely to provide focused, scholarly, and comprehensive overviews of a given transformation, that Organic Reactions takes on even greater significance for the practice of chemical experimentation in the 21st century.
Adams' description of the content of the intended chapters is still remarkably relevant today. The development of new chemical reactions over the past decades has greatly accelerated and has embraced more sophisticated reagents derived from elements representing all reaches of the Periodic Table. Accordingly, the successful implementation of these transformations requires more stringent adherence to important experimental details and conditions. The suitability of a given reaction for an unknown application is best judged from the informed vantage point provided by precedent and guidelines offered by a knowledgeable author.
As Adams clearly understood, the ultimate success of the enterprise depends on the willingness of organic chemists to devote their time and efforts to the preparation of chapters. The fact that, at the dawn of the 21st century, the series continues to thrive is fitting testimony to those chemists whose contributions serve as the foundation of this edifice. Chemists who are considering the preparation of a manuscript for submission to Organic Reactions are urged to contact the Editor‐in‐Chief.
PREFACE TO VOLUME 106
Something old, something new, Something borrowed, something blue, and a sixpence in her shoe.
Anon (1871)
St James' Magazine, London
The two chapters in this volume of Organic Reactions epitomize the sentiment of the traditional old English rhyme, in that the combination of something old with something new often provides a different perspective, and thus, important new possibilities. The first two lines of the verse were originally published in a magazine article on Marriage Superstitions in 1871. The something old is meant to ward off evil spirits, whereas something new offers optimism for the future. The something borrowed is thought to bring good luck, and the something blue represents purity and fidelity. The final line, and a sixpence in her shoe, was introduced during the Victorian era to represent prosperity. Although there were originally minor regional variations, this version has now been endorsed internationally, which exemplifies the impact of a simple piece of prose. The development of a synthetic transformation has many of the attributes delineated within this simple rhyme, wherein the combination of something old with something new can significantly extend the reaction scope and synthetic utility. The something borrowed and something blue could represent the serendipitous discoveries that often result in a very fertile area of investigation that advances a process in the context of efficiency and selectivity. In some cases, these findings can lead to commercial applications that can be lucrative to the inventor, which ties into the rhyme's last line. The two chapters in this volume focus on transformations connected by the preparation and reactions of alkenes. Notably, the cross‐metathesis reaction involves the catalytic construction of acyclic alkenes, whereas the Stetter reaction entails the catalytic enantioselective conjugate addition of aldehydes to alkenes.
The first chapter by Karol Grela, Anna Kajetanowicz, Anna Szadkowska, and Justyna Czaban‐Jóźwiak provides an extensive review on alkene cross‐metathesis, which completes the trilogy of chapters dealing with metathesis reactions. The two earlier chapters were on olefin ring‐closing metathesis by Larry Yet (Volume 89) and alkyne metathesis by Daesung Lee, Ivan Volchkov, and Sang Young Yun (Volume 102). The term “olefin metathesis” was coined by Calderon in 1967, wherein the word metathesis means “transposition” and is the combination of two Greek words–change (meta) and position (thesis). The reaction was serendipitously discovered in the 1950s and is often referred to as the “child of industry” because of the strong industrial connection. Chemists at Du Pont, Standard Oil, and Phillips Petroleum independently reported the metathesis of propene and other variants. In the late 1980s and early 1990s, Grubbs and Schrock, who received the 2005 Nobel Prize in Chemistry with Yves Chauvin for their work on olefin metathesis, developed well‐behaved ruthenium, molybdenum and tungsten catalysts that were compatible with functionalized alkenes required for fine chemical synthesis and the field exploded exponentially. This chapter delineates the historical development of the cross‐metathesis reaction from an academic/industrial curiosity to a sophisticated modern transformation for the catalytic construction of acyclic alkenes in a highly selective manner. The Mechanism and Stereochemistry section provides an insightful account of reaction initiation, catalyst regeneration, and stereocontrol. For example, the difference between the three initiation processes, the so‐called “boomerang” mechanism, and the various aspects of diastereo‐ and enantioselective cross‐metathesis reactions are discussed. Importantly, the latter part outlines the catalyst requirements for controlling (E)‐ and (Z)‐geometry, the desymmetrization of prochiral meso‐compounds through asymmetric ring‐opening cross‐metathesis (AROCM), and asymmetric cross‐metathesis (ACM). The Scope and Limitations component delineates the classification of alkenes (Types I‐IV according to Grubbs), the consequences of their ability to undergo cross‐metathesis, and the impact of the classification on the mechanism in terms of homodimerization. This section is organized by various alkene substituents, including boron, nitrogen, oxygen, halogens, silicon, tin, phosphorus, sulfur, etc. There is also a substantial section on (Z)‐selective processes that have proven particularly challenging, and, as such, makes the addition of this section very timely. The Applications to Synthesis section describes several impressive natural product syntheses that use this reaction, and the Comparison with Other Methods section provides a comprehensive assessment of more classical methods that are commonly deployed to construct alkenes. The Tabular Survey incorporates reactions reported up to March 2020. The tables are organized by the type of olefin metathesis (according to Grubbs) and then further subdivided by functional groups, which makes identifying a particular combination effortless. Overall, this is a superb chapter on a fundamentally important process that will be an invaluable resource to anyone wishing to construct an olefin using a cross‐metathesis reaction.
The second chapter by Darrin M. Flanigan, Kerem E. Ozboya, Alberto Muñoz, Tomislav Rovis, Subhash D. Tanpure, and Paul R. Blakemore chronicles the development of the catalytic enantioselective Stetter reaction, which represents an update to the original chapter by Stetter and Kuhlmann in Volume 40. This process is closely related to the venerable acyloin condensation, which is catalyzed by cyanide and vitamin B1 (thiamine) in Nature. While plants tend to employ cyanide derived from cyanoglucosides, other living organisms use non‐toxic thiamine and the reaction proceeds via the so‐called “Breslow Intermediate” from the addition of the deprotonated quaternary thiazolium salt to pyruvate. The recognition that an aldehyde's natural electrophilicity can be reversed to afford the requisite acyl anion equivalent prompted Hermann Stetter to examine the cyanide‐catalyzed addition of aromatic aldehydes to α,β‐unsaturated esters, ketones, and nitriles in the early 1970s. He later demonstrated that thiazolylidenes also catalyze this process to permit the coupling of two formally electrophilic species for construction of 1,4‐dicarbonyls that constitute useful intermediates for target‐directed synthesis. Although the catalyst requirement mitigates any background reaction, the first enantioselective process was not described until the mid‐1990s by Dieter Enders using a chiral triazolium catalyst. Consequently, this important and seminal report set the wheels in motion for others to develop more selective and versatile catalysts that significantly broaden the substrate scope. This chapter catalogs the development of the enantioselective variant that has emerged as a powerful synthetic tool for target‐directed synthesis. The Mechanism and Stereochemistry section outlines the various methods for generating the NHC catalysts from the corresponding salts and the subsequent formation and reactivity of Breslow intermediates, including associated mechanistic experiments, namely, deuterium isotope and competition studies. The section on stereochemistry presents a series of models that rationalize the origin of stereocontrol, including computational studies on the preferred enaminol geometry and the transition state for the key C‐C bond‐forming event. The Scope and Limitations component documents the preparation of triazolium salts, and the remainder of the discussion is organized by the different intra‐ and intermolecular variants. The authors subdivide this section by the type of aldehyde donor (aryl, aliphatic, α,β‐unsaturated, etc.). A section on the recent aza‐Stetter reaction with imine donors may also be of interest to the reader. The Applications to Synthesis section provides some unique applications to the synthesis of natural products, and the Comparison with Other Methods section provides a detailed comparison with several alternative methods. The organization of the Tabular Survey mirrors the Scope and Limitations section, thereby making it easy for the reader to identify a specific transformation. Overall, this is an outstanding chapter on a particularly important and useful process that will be a valuable resource to the synthetic community.
I would be remiss if I did not acknowledge the entire Organic Reactions Editorial Board for their collective efforts in steering this volume through the various stages of the editorial process. I want to thank Steven M. Weinreb (Chapter 1 and 2), the Responsible Editor for the two chapters, albeit I had some early input into Chapter 2 through the early phases of development. I am also deeply indebted to Dr. Danielle Soenen for her heroic efforts as the Editorial Coordinator; her knowledge of Organic Reactions is critical to maintaining consistency in the series. Dr. Dena Lindsay (Secretary to the Editorial Board) is thanked for coordinating the author's, editor's, and publisher's contributions. In addition, the Organic Reactions enterprise could not maintain the quality of production without the efforts of Dr. Steven M. Weinreb (Executive Editor), Dr. Engelbert Ciganek (Editorial Advisor), Dr. Landy Blasdel (Processing Editor), and Dr. Debra Dolliver (Processing Editor). I would also like to acknowledge Dr. Barry R. Snider (Secretary) for keeping everyone on task and Dr. Jeffery Press (Treasurer) for making sure that we are fiscally solvent!
I am also indebted to past and present members of the Board of Editors and Directors for ensuring the enduring quality of Organic Reactions. The unique format of the chapters, in conjunction with the collated tables of examples, make this series of reviews both unique and exceptionally valuable to the practicing synthetic organic chemist.
P. Andrew Evans
Kingston
Ontario, Canada
CHAPTER 1ALKENE CROSS‐METATHESIS REACTIONS
KAROL GRELA, ANNA KAJETANOWICZ, AND ANNA SZADKOWSKA
Biological and Chemical Research Centre, Faculty of Chemistry, University of Warsaw, Żwirki i Wigury 101, 02‐089, Warsaw, Poland
ANNA KAJETANOWICZ AND JUSTYNA CZABAN‐JÓŹWIAK
Institute of Organic Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01‐224, Warsaw, Poland
Edited by STEVEN M. WEINREB
CONTENTS
ACKNOWLEDGMENTS
INTRODUCTION
Types of Olefin Metathesis
Metathesis (Pre)‐Catalysts
MECHANISM AND STEREOCHEMISTRY
General Mechanism for Olefin Metathesis
Mechanism for Initiation of Metathesis Catalysts
Associative Mechanism
Dissociative Mechanism
Interchange Mechanism
“Boomerang” Mechanism of Regeneration of Hoveyda–Grubbs‐Type Complexes
Stereochemistry
Diastereoselectivity
Enantioselectivity
Asymmetric Cross‐Metathesis (ACM)
Asymmetric Ring‐Opening Cross‐Metathesis (AROCM)
SCOPE AND LIMITATIONS
Introduction
Metathesis Catalysts
Influence of Functional Groups on Alkene Classification and Selectivity
Hydrogen as a Functional Group (Ethenolysis)
Boron‐Bearing Alkenes
Alkenes with Carbon‐Based Functional Groups
Alkenes Containing Linear Alkyl Groups
Sterically Hindered Alkenes
Alkenes Bearing Additional Carbon–Carbon Double Bonds
Alkenes Containing Perfluoroalkyl Groups
Alkenes Bearing Aryl and Heteroaryl Substituents
Unsaturated Nitriles
Unsaturated Aldehydes
Unsaturated Ketones
Unsaturated Carboxylic Acids and Their Derivatives
Alkenes That Have Nitrogen‐Based Substituents
Allylic and Homoallylic Amines
Unsaturated Azides
Unsaturated Nitro Compounds
Alkenes Containing an Oxygen Moiety
Unsaturated Alcohols
Unsaturated Ethers, Epoxides, and Peroxides
Haloalkenes
Unsaturated Compounds Containing Silicon and Tin
Vinylsilanes
Allylsilanes
Unsaturated Phosphorus Compounds
Alkenes Containing a Phosphine–Borane Moiety
Alkenes Containing a Phosphine Oxide Moiety
Unsaturated Phosphonates
Alkenes Containing Sulfur and Selenium Moieties
Unsaturated Thiols and Sulfides
Unsaturated Sulfoxides
Unsaturated Sulfones
Unsaturated Sulfonamides
(
Z
)‐Selective Metathesis
APPLICATIONS TO SYNTHESIS
Cross‐Metathesis in Natural Products Synthesis
COMPARISON WITH OTHER METHODS
Elimination Reactions
Alkenation of Carbonyl Compounds
Transition‐Metal‐Catalyzed Cross‐Coupling Reactions
EXPERIMENTAL CONDITIONS
EXPERIMENTAL PROCEDURES
(
R
)‐2‐Methylbut‐3‐enyl Methanesulfonate [Ethenolysis of a Mesylate (Type I Alkene)].330
(2
S
,7
S,E
)‐
tert
‐Butyl 7‐(
tert
‐Butoxycarbonylamino)‐2‐(9
H
‐fluoren‐9‐ylmethoxycarbonylamino)‐7‐(methoxycarbonyl)hept‐4‐enoate [Cross‐Metathesis of Two Type I Alkenes]. 331
2,3,4,5‐Tetra‐
O
‐acetyl‐α‐pentadec‐2‐enyl D‐Galactoside [Cross‐Metathesis of an Allylic Ether (Type I Alkene)]. 332
Diethyl 2‐(
R
)‐(3‐(4,4,5,5‐Tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)allyl)succinate [Cross‐Metathesis of a Vinyl Boronic Ester (Type II Alkene)]. 333
(
S,E
)‐5‐((4
S
,5
R
)‐2,2‐Dimethyl‐5‐((
S
)‐oxiran‐2‐yl)‐1,3‐dioxolan‐4‐yl)pent‐4‐en‐2‐ol [Cross‐Metathesis of an Acetal (Type II Alkene)]. 334
(
E
)‐
N
‐(1‐Cyclopropyl‐5‐oxohex‐3‐en‐1‐yl)‐4‐methylbenzenesulfonamide [Cross‐Metathesis of an α,β‐Unsaturated Ketone (Type II Alkene)]. 335
(5
R
)‐5‐Hydroxy‐7‐methyl‐oct‐2‐enoic Acid Methyl Ester [Cross‐Metathesis of Methyl Acrylate (Type II Alkene)]. 336
Methyl (
S
)‐2‐Benzamido‐5‐phenylhex‐4‐enoate [Cross‐Metathesis of α‐ Methylstyrene (Type III Alkene)]. 337
Dihydro‐3‐(2‐(4‐hydroxy‐3‐methoxyphenyl)ethylidene)furan‐2(
3
H
)‐one [Cross‐Metathesis of a Lactone with an Exocyclic Double Bond (Type III Alkene)]. 173
tert
‐Butyldimethyl((7‐nitrohept‐5‐en‐1‐yl)oxy)silane [Cross‐Metathesis of an Allylic Nitro Compound (Type III Alkene)]. 179
1‐[(
E,Z
)‐2‐Chloroethenyl]‐4‐methoxybenzene [Cross‐Metathesis of a Vinyl Halide (Type III Alkene)]. 105
(
E
)‐2‐(4‐Bromophenyl)vinylheptaisobutyl‐T8‐silsesquioxane [Cross‐Metathesis of a Vinyl Siloxane (Type III Alkene)]. 338
(
E
)‐[2‐(4‐Methoxyphenyl)vinyl]diphenylphosphine Oxide [Cross‐Metathesis of a Vinyl Phosphine Oxide (Type III Alkene)]. 215
Diethyl 2‐[(
E
)‐3‐(Phenylsulfonyl)‐2‐propenyl]malonate [Cross‐Metathesis of a Vinyl Sulfone (Type III Alkene)]. 228
(5
R
,6
S
)‐5‐((
Z
)‐2‐Butoxyvinyl)‐2,2,3,3,8,8,9,9‐octamethyl‐6‐vinyl‐4,7‐dioxa‐3,8‐disiladecane [AROCM of a Vinyl Ether (Type III Alkene)]. 339
3‐Benzyloxy‐2,4‐dimethyl‐1‐(1
H
‐pyrrol‐2‐yl)nona‐5,8‐diene‐1,7‐dione [Tandem ROCM of a Cyclopropenone Ketal (Type II Alkene)]. 340
4‐Phenyl‐2‐butenyl Acetate [Cross‐Metathesis in Water]. 32, 341
(2
S
,6
R
,
E
)‐7‐(
tert
‐Butyldimethylsilyloxy)‐2‐hydroxy‐2,6‐dimethylhept‐3‐enyl Benzoate [Cross‐Metathesis in a Fluorinated Solvent]. 342
(
E
/
Z
)‐Ethyl 3‐(3‐Acetoxyprop‐1‐enyl)‐2,2‐dimethylcyclopropanecarboxylate [Cross‐Metathesis Assisted by Microwave Irradiation]. 40
Dimethyl 4,4′‐Stilbenedicarboxylate [Mechanochemically Induced Cross‐Metathesis]. 343
TABULAR SURVEY
Chart 1. Ruthenium Catalysts Used in the Tables
Chart 2. Molybdenum Catalysts Used in the Tables
Chart 3. Tungsten Catalysts Used in the Tables
TYPE I (ACCORDING TO GRUBBS)
Table 1. Cross-Metathesis of Unsaturated Compounds with Functional Groups in Homoallylic and More Distant Positions
A. Ethylene and Compounds with a Terminal Double Bond
B. Compounds with an Internal Double Bond
C. Compounds with Conjugated Double Bonds
Table 2. Cross-Metathesis of Allylic Boronates
Table 3. Cross-Metathesis of Allylic Amines (Not Including Amines with a Substituted Carbon in the α-Position)
A. Primary Amines
B. Secondary Amines
C. Tertiary Amines
Table 4. Cross-Metathesis of Primary Allylic Alcohols and Derivatives
A. Allylic Alcohols
B. Allylic Ethers
C. Allylic Esters
Table 5. Cross-Metathesis of Primary Allylic Halides and 1,4-Dihalobut-2-enes
Table 6. Cross-Metathesis of Allylsilanes
Table 7. Cross-Metathesis of Allylic Organophosphorus Compounds
A. Allylphosphonates
B. Allyl Phosphine Oxides
C. Allyl Phosphine Boranes
Table 8. Cross-Metathesis of Primary Allylic Organosulfur and Organoselenium Compounds
A. Allylic Sulfides and Selenides
B. Sulfonium Salts
C. Allylic Sulfoxides, Sulfones, and Sulfonamides
TYPE II (ACCORDING TO GRUBBS)
Table 9. Cross-Metathesis of Vinyl-Substituted Heteroaromatic Compounds
Table 10. Cross-Metathesis of Vinyl-Substituted Aromatic Compounds
Table 11. Cross-Metathesis of Vinyl Boronic Compounds
A. Vinyl Boronic Acids
B. Vinyl Boronic Esters
Table 12. Cross-Metathesis of Allylic Amines (Amines Substituted on the α-Carbon)
A. Primary Amines
B. Secondary Amines
C. Tertiary Amines
Table 13. Cross-Metathesis of Secondary Allylic Alcohols and Derivatives
A. Allylic Alcohols
B. Allylic Ethers
C. Allylic Esters
D. Acetals
Table 14. Cross-Metathesis of Tertiary Allylic Alcohols and Derivatives
Table 15. Cross-Metathesis of Vinyl Epoxides
Table 16. Cross-Metathesis of α, β-Unsaturated Aldehydes
Table 17. Cross-Metathesis of α, β-Unsaturated Ketones
Table 18. Cross-Metathesis of α, β-Unsaturated Acrylic Acids
Table 19. Cross-Metathesis of Acryloyl Chloride
Table 20. Cross-Metathesis of α, β-Unsaturated Esters and Thioesters
A. Esters
B. Thioesters
Table 21. Cross-Metathesis of α, β-Unsaturated Amides
Table 22. Cross-Metathesis of Secondary Allylic Halides
Table 23. Cross-Metathesis of Allylstannanes
TYPE III (ACCORDING TO GRUBBS)
Table 24. Cross-Metathesis of Alkenes with Quaternary Allylic Carbon Centers
Table 25. Cross-Metathesis of Geminal-Disubstituted Compounds
A. Alkenes with Functional Groups in Allylic and More Distant Positions
B. Boronic Esters
C. Lactones with an Exocyclic C–C Double Bond
D. Lactams with an Exocyclic C–C Double Bond
E. α-Methacrylates
Table 26. Cross-Metathesis of Allylic Nitro Compounds
Table 27. Cross-Metathesis of Acrylonitrile and Methacrylonitrile
Table 28. Cross-Metathesis of Vinyl Ethers and Esters
A. Vinyl Ethers
B. Vinyl Esters
Table 29. Cross-Metathesis of Vinylic Compounds with a Perfluorinated Carbon Chain
Table 30. Cross-Metathesis of Vinyl Halides
Table 31. Cross-Metathesis of Vinyl Silanes and Siloxanes
A. Vinyl Silanes
B. Vinyl Siloxanes
Table 32. Cross-Metathesis of Vinylic Organophosphorus Compounds
A. Vinyl Phosphonates
B. Vinyl Phosphine Oxides
C. Vinyl Phosphine Boranes
Table 33. Cross-Metathesis of Vinylic Organosulfur Compounds
A. Vinyl Thioethers
B. Vinyl Sulfones
C. Vinyl Sulfonamides
Table 34. Asymmetric Cross-Metathesis
Table 35. Ring-Opening Cross-Metathesis
Table 36. Asymmetric Ring-Opening Cross-Metathesis
REFERENCES
ACKNOWLEDGMENTS
A. K. thanks the Foundation for Polish Science for a Homing Plus grant (HOMING PLUS/2013‐7/6). K. G. thanks the Foundation for Polish Science for a “Wyjazdowe Stypendium Naukowe” (WSN‐2016) Professorship. J. C.‐J. thanks the Foundation for Polish Science for a Ventures grant (Ventures/2011–7/3).
0
INTRODUCTION
The term metathesis means “transposition” and comes from the Greek words μετα (“meta”, meaning “change”) and θεσις (“thesis”, meaning “position”). The term “olefin metathesis” was coined in 19671 and refers to the metal‐catalyzed redistribution of carbon–carbon double bonds. Thus, in olefin metathesis, carbons at the termini of two alkenes are exchanged to afford two new alkenes (Scheme 1).
Scheme 1
Transition‐metal‐catalyzed olefin metathesis is one of the most powerful tools in organic chemistry for the formation of carbon–carbon double bonds.2–4 This method has revolutionized the synthesis of a wide variety of useful organic molecules, with far‐reaching applications in natural product synthesis,5–8 medicinal chemistry,9 macromolecular architectures,10,11 solid‐phase chemistry,12,13 polymerization,14–17 fine chemicals,18 and target‐oriented synthesis.19 The spectacular success of this reaction culminated in the 2005 Nobel Prize in Chemistry being awarded to three primary contributors to this field: Grubbs, Schrock, and Chauvin.20
Types of Olefin Metathesis
The main advantage of this method is that several types of olefin metathesis transformations can be performed with the same catalysts, depending on the reaction conditions and on the structural features of the substrates, as illustrated in Scheme 2.3,7,19,22 Since the metathesis process is energetically neutral and reversible, a mixture of both starting substrates and products is obtained at equilibrium. Nevertheless, this intrinsic problem can be circumvented by the judicious choice of substrates and/or reaction conditions, so that one product type can be prepared selectively.
Scheme 2
To date, the most widely used olefin metathesis reaction among synthetic organic chemists is the ring‐closing metathesis (RCM) of dienes.10,23–26 The formation of a ring is usually accompanied by the production of an equivalent of a volatile alkene (e.g., ethylene), which can be easily removed, thereby shifting the equilibrium toward the desired product. RCM facilitates the formation of many ring sizes, from five‐membered rings to macrocycles of greater than 20 atoms.
The energy gained upon release of strain with cyclic alkenes (e.g., norbornene derivatives) is the driving force behind ring‐opening metathesis polymerization (ROMP).14,16,27 In many cases, the ROMP of strained cyclic alkenes initiated by metal alkylidene complexes exhibits the characteristic features of a living polymerization, and therefore, block copolymers can be prepared by sequential addition of different alkene monomers.
Acyclic diene metathesis polymerization (ADMET) is a second metathetical method for making polymers.28–31 Dienes are polymerized with concomitant release of a low‐molecular‐weight, volatile alkene, usually ethylene. The polymer chain can grow further, usually in a living manner, by reaction with the double bond of a second diene molecule. ROMP and ADMET have been used to construct polymeric materials with a wide range of properties, including those with biological activity.
Intermolecular mutual exchange of alkylidene (or carbene) fragments between two alkene partners is known as cross‐metathesis (CM).32–36 The biggest challenge in cross‐metathesis is the chemo‐ and stereoselective formation of the desired compound from several potential reaction products. There are a few variations on the theme of cross‐metathesis (Scheme 3): (1) cross‐metathesis, (2) ring‐opening cross‐metathesis (ROCM),37,38 and (3) enyne metathesis.
Scheme 3
Enyne metatheses are unique and interesting transformations that involve the reaction of an alkene and an alkyne. Two main types of enyne metathesis exist, namely, intermolecular and intramolecular variations. The products from these processes are synthetically useful butadiene derivatives, which lend themselves to structural elaboration, for example by Diels–Alder reactions and other cycloaddition processes. The intramolecular variant (sometimes called metathetical cycloisomerization of enynes) leads to cyclic products, including four‐membered rings.39,40
Compounds containing several double and triple carbon–carbon bonds can undergo sequential or domino metathesis.41–44
Due to the importance of cross‐metathesis reactions, several reviews have appeared on this topic.45–50 Reviews by Blechert,45 Astruc,2,51 Fürstner,19,52 and Grela47 discuss olefin metathesis in general, whereas reviews by Grubbs,46 Blechert,34 Grela,48,49 and O'Leary50 address only cross‐metathesis. This chapter focuses on state of the art methods in cross‐metathesis, and the Tables provide examples through March 2020.
Metathesis (Pre)‐Catalysts
Olefin metathesis catalysts are based on tungsten, molybdenum, and ruthenium. In general, ruthenium complexes are more stable towards air and moisture, while tungsten and molybdenum catalysts are more active and more resistant towards ethylene (the ruthenium methylidene complexes, [Ru]=CH2, are relatively short‐lived).53–56 The most commonly used metathesis catalysts are presented in Figure 1 and are described in detail in “Metathesis Catalysts”.
Figure 1 Grubbs (Ru‐1, Ru‐4), Hoveyda–Grubbs (Ru‐2, Ru‐5), indenylidene (Ru‐3, Ru‐6) and Schrock (Mo‐1) complexes.
MECHANISM AND STEREOCHEMISTRY
General Mechanism for Olefin Metathesis
Several mechanistic hypotheses were proposed during early olefin metathesis exploration.1,57,58 The commonly accepted mechanism involves first an alkylidene exchange between two reacting alkenes mediated by a transition‐metal complex through formation of metallacyclobutanes as the pivotal intermediates (Scheme 4). The CM reaction is initiated when a metal alkylidene (methylidene) of type 4—the active catalyst—reacts with the alkene substrate (1). Metallacyclobutane 5 is formed as an intermediate, in turn producing either ethylene and a new metal alkylidene 6
