Organic Reactions, Volume 107 E-Book
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- Herausgeber: John Wiley & Sons
- Kategorie: Wissenschaft und neue Technologien
- Serie: Organic Reactions
- Sprache: Englisch
The 107th volume in this series for organic chemists in academia and industry presents critical discussions of the following widely used organic reactions: ENANTIOSELECTIVE HYDROFORMYLATION Toshiki Tazawa, Andreas Phanopoulos, and Kyoko Nozaki HAUSER KRAUS, SAMMES, STAUNTON WEINREB, AND TAMURA ANNULATIONS Charles B. de Koning, Kathy Hadje Georgiou, Joseph P. Michael, and Amanda L. Rousseau
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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 107
DR. DEBRA D. DOLLIVER 1960–2021
CHAPTER 1: ENANTIOSELECTIVE HYDROFORMYLATION
INTRODUCTION
MECHANISM AND STEREOCHEMISTRY
SCOPE AND LIMITATIONS
APPLICATIONS TO SYNTHESIS
COMPARISON WITH OTHER METHODS
EXPERIMENTAL CONDITIONS
EXPERIMENTAL PROCEDURES
TABULAR SURVEY
References
CHAPTER 2: HAUSER–KRAUS, SAMMES, STAUNTON–WEINREB, AND TAMURA ANNULATIONS
ACKNOWLEDGMENTS
INTRODUCTION
MECHANISM
SCOPE AND LIMITATIONS
APPLICATIONS TO SYNTHESIS
COMPARISON WITH OTHER METHODS
EXPERIMENTAL CONDITIONS
EXPERIMENTAL PROCEDURES
TABULAR SURVEY
References
Additional Supplemental References
CUMULATIVE CHAPTER TITLES BY VOLUME
Author Index, volumes OR 1–107
CHAPTER AND TOPIC INDEX, VOLUMES 1–107
End User License Agreement
List of Tables
Chapter 1
Table A . Examples of asymmetric hydroformylation of heterocyclic alkenes usi...
List of Illustrations
Chapter 1
Scheme 1
Scheme 2
Figure 1 The binaphyl moiety featuring two linked naphthal groups.
Scheme 3
Scheme 4
Scheme 5
Scheme 6
Scheme 7
Figure 2 Favored regio‐determining reaction pathways for vinyl arenes and vi...
Figure 3 Stabilizing interactions that prevent linear aldehyde formation.
Figure 4 Quadrant model for stereoinducing transition step.
Scheme 8
Scheme 9
Scheme 10
Scheme 11
Scheme 12
Scheme 13
Scheme 14
Scheme 15
Scheme 16
Figure 5 Chiral α,ω‐bisphosphite ligands with polyether linkers used in conj...
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
Figure 6 Structural formula of tedanolide C.
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
Chapter 2
Scheme 1
Scheme 2
Scheme 3
Scheme 4
Scheme 5
Scheme 6
Scheme 7
Scheme 8
Scheme 9
Scheme 10
Scheme 11
Scheme 12
Scheme 13
Scheme 14
Scheme 15
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
Figure 1 Nucleophilic partners for Hauser–Kraus annulations: (a) phthalides;...
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
Scheme 66
Scheme 67
Scheme 68
Scheme 69
Scheme 70
Scheme 71
Scheme 72
Scheme 73
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Scheme 75
Scheme 76
Scheme 77
Scheme 78
Scheme 79
Scheme 80
Scheme 81
Scheme 82
Scheme 83
Scheme 84
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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
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Scheme 100
Scheme 101
Scheme 102
Scheme 103
Scheme 104
Scheme 105
Scheme 106
Scheme 107
Scheme 108
Scheme 109
Scheme 110
Scheme 111
Scheme 112
Scheme 113
Scheme 114
Scheme 115
Scheme 116
Scheme 117
Scheme 118
Scheme 119
Scheme 120
Scheme 121
Scheme 122
Scheme 123
Scheme 124
Scheme 125
Scheme 126
Scheme 127
Scheme 128
Scheme 129
Scheme 130
Scheme 131
Scheme 132
Scheme 133
Scheme 134
Scheme 135
Scheme 136
Scheme 137
Scheme 138
Scheme 139
Scheme 140
Scheme 141
Scheme 142
Scheme 143
Scheme 144
Scheme 145
Scheme 146
Scheme 147
Scheme 148
Scheme 149
Scheme 150
Scheme 151
Scheme 152
Figure 2 Heterocyclic esters that participate in Staunton–Weinreb annulation...
Scheme 153
Scheme 154
Scheme 155
Scheme 156
Scheme 157
Scheme 158
Scheme 159
Scheme 160
Scheme 161
Scheme 162
Scheme 163
Scheme 164
Scheme 165
Scheme 166
Scheme 167
Scheme 168
Scheme 169
Scheme 170
Scheme 171
Scheme 172
Scheme 173
Scheme 174
Scheme 175
Scheme 176
Scheme 177
Scheme 178
Scheme 179
Scheme 180
Scheme 181
Scheme 182
Scheme 183
Scheme 184
Scheme 185
Scheme 186
Scheme 187
Scheme 188
Scheme 189
Scheme 190
Scheme 191
Scheme 192
Scheme 193
Scheme 194
Scheme 195
Scheme 196
Scheme 197
Scheme 198
Scheme 199
Scheme 200
Scheme 201
Scheme 202
Scheme 203
Scheme 204
Scheme 205
Scheme 206
Scheme 207
Scheme 208
Scheme 209
Figure 3 Cyclic anhydrides that participate in Tamura annulations.
Scheme 210
Scheme 211
Scheme 212
Scheme 213
Scheme 214
Scheme 215
Scheme 216
Scheme 217
Scheme 218
Scheme 219
Scheme 220
Scheme 221
Scheme 222
Scheme 223
Scheme 224
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Scheme 226
Scheme 227
Scheme 228
Scheme 229
Scheme 230
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Scheme 232
Scheme 233
Scheme 234
Scheme 235
Scheme 236
Scheme 237
Scheme 238
Scheme 239
Scheme 240
Scheme 241
Scheme 242
Scheme 243
Scheme 244
Scheme 245
Scheme 246
Scheme 247
Scheme 248
Scheme 249
Scheme 250
Scheme 251
Scheme 252
Scheme 253
Figure 4 Phthalide and homophthalic anhydride numbering.
Guide
Cover Page
Editors
Title Page
Copyright
INTRODUCTION TO THE SERIES BY ROGER ADAMS, 1942
INTRODUCTION TO THE SERIES BY SCOTT E. DENMARK, 2008
PREFACE TO VOLUME 107
Dr. DEBRA D. DOLLIVER 1960–2021
Table of Contents
Begin Reading
CUMULATIVE CHAPTER TITLES BY VOLUME
AUTHOR INDEX, VOLUMES OR 1–107
CHAPTER AND TOPIC INDEX, VOLUMES 1–107
WILEY END USER LICENSE AGREEMENT
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FORMER MEMBERS OF THE BOARDOF 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 BOARDNOW 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 107
EDITORIAL BOARD
P. ANDREWEVANS, Editor‐in‐Chief
STEVEN M. WEINREB, Executive Editor
DAVID
B.
BERKOWITZ
STEFAN
LUTZ
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
JEFFREY
N.
JOHNSTON
BARRY B. SNIDER, Secretary
JEFFERY B. PRESS, Treasurer
DANIELLESOENEN, Editorial Coordinator
DENALINDSAY, Secretary and Processing Editor
LANDY K. BLASDEL, Processing Editor
DEBRADOLLIVER, Processing Editor
ENGELBERTCIGANEK, Editorial Advisor
ASSOCIATE EDITORS
CHARLES B. DE KONING
KATHYHADJEGEORGIOU
JOSEPH P. MICHAEL
KYOKONOZAKI
ANDREASPHANOPOULOS
AMANDA L. ROUSSEAU
TOSHIKITAZAWA
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978‐1‐119‐77126‐5
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 107
Life isn't just addition and subtraction.
There is also the accumulation, the multiplication, of loss, of failure.
Julian Barnes, 2011
The Sense of an Ending
The two chapters in this volume of Organic Reactions reflect the notion of addition and subtraction, which are formally two sides of the same coin. For example, the addition of HX to an alkene gives a haloalkane with loss of the double bond, whereas the elimination of HX from a haloalkane does the converse. Indeed, this sentiment is the very cornerstone of designing a successful sequence of bond‐forming reactions that culminate in the conversion of one functional group into another in an orchestrated series of events to deliver a specific target with the desired properties. Hence, addition and subtraction are omnipresent in a particular sequence of reactions, irrespective of the nature and complexity of the transformations involved. The second line of the quote could pertain to the toil of discovery, in which the accumulation and multiplication of loss and failure are a prerequisite for the development of a new process. Indeed, any chemist can attest to the anguish and euphoria involved in developing a new transformation or synthetic route. Nevertheless, one critical facet of organic chemistry is the ability to convert failure into success and thus generate a body of work that disguises the many hours of loss and failure in the pursuit of success. A particularly attractive feature with the Organic Reactions series is the collation of this work in a single chapter to permit the chemist to compare and contrast these variations to provide confidence in selecting specific reaction conditions for a new application that mitigate the chances of failure. The two chapters in this volume focus on transformations connected by the addition and subtraction of functional groups that lead to more complex and valuable entities. The first chapter deals with the venerable hydroformylation reaction, and the second chapter delineates the Hauser–Kraus, Sammes, Staunton–Weinreb, and Tamura Annulations. Although both reactions involve olefin addition reactions, the latter is formally a cycloaddition of a 1,4‐dipole.
The first chapter by Toshiki Tazawa, Andreas Phanopoulos, and Kyoko Nozaki is an excellent treatise on the enantioselective hydroformylation reaction, which is the net addition of a formyl group and a hydrogen atom to an olefin catalyzed by a chiral late transition‐metal catalyst. Otto Roelen serendipitously discovered the hydroformylation reaction in 1938 during investigations of the Fischer‐Tropsch process. Remarkably, the reaction has become an important industrial process responsible for the annual global production of more than 10 million tons of so‐called “oxo” products. Although the reaction delivers both branched and linear aldehydes, it is the preparation of branched chiral nonracemic aldehydes that has recently attracted considerable attention, largely because chiral aldehydes are important intermediates for pharmaceuticals, agrochemicals, flavors, fragrances, and other fine chemicals. This chapter delineates the development of the enantioselective hydroformylation reaction from preliminary work with platinum catalysts to the more reactive rhodium variants, thereby complementing and updating an earlier chapter by Iwao Ojima, Chung‐Ying Tsai, Maria Tzamarioudaki, and Dominique Bonafoux (Volume 56, 2000) that primarily focused on the preparation of achiral linear aldehydes. The Mechanism and Stereochemistry section focuses entirely on the rhodium‐catalyzed reaction, providing an insightful account into the general catalytic cycle and the origin of regio‐ and enantioselectivity. For instance, the general catalytic cycle details Wilkinson's dissociative mechanism in the context of mono‐ and bidentate phosphine ligands, which includes different sources of hydrogen and carbon monoxide. The origin of regio‐ and enantioselectivity is discussed in the context of reaction conditions that render this process irreversible, namely pressure, temperature, etc., using the insight gleaned from both experimental and computational studies. The Scope and Limitations component is organized using the alkene as the primary rubric, namely vinyl arenes, aliphatic acyclic alkenes, heteroatom‐substituted acyclic alkenes, α,β‐unsaturated carbonyl compounds, allylic‐ and homoallylic‐substituted acyclic alkenes, conjugated dienes, and cyclic alkenes. The Applications to Synthesis section describes several applications to natural product syntheses, and the Comparison with Other Methods section provides a critical assessment of more classical methods that are commonly deployed for the construction of aldehydes bearing α‐ and β‐stereogenic centers. The Tabular Survey incorporates reactions reported up to June 2020 and mirrors the Scope and Limitations section to permit the reader to easily identify a specific reaction combination of interest. The authors have applied a lower limit of enantioselectivity to primarily focus on examples of practical interest while maintaining the necessary scholarship to define the limitations in a valuable and informative manner. Overall, this excellent chapter on a fundamentally important reaction, that continues to generate considerable interest provides a valuable resource for practicing synthetic chemists in both academia and industry.
The second chapter by Charles B. de Koning, Kathy Hadje Georgiou, Joseph P. Michael, and Amanda L. Rousseau delineates the development of the Hauser–Kraus, Sammes, Staunton–Weinreb, and Tamura Annulations. These annulations are all closely related and date back to Schmid's early work in the mid‐1960s, which employed an ester‐stabilizing group to generate the enolate using sodium in ethanol. Further studies in the late 1970s and early 1980s initiated a series of adaptations that permit access to similar annulated products, albeit with the newly formed ring at different oxidation states. This class of annulation reactions is based on the addition of a 1,4‐dipole equivalent to a Michael acceptor with a concomitant Dieckmann or Claisen condensation to complete the annulation. The chapter independently catalogs the development of each of these variants, which provides a versatile strategy for constructing annulated six‐membered rings. The Mechanism section outlines the two most common mechanistic scenarios for this type of process, which either proceed through the stepwise addition of the formal 1,4‐dipole or a [4+2] cycloaddition of the dienolate mesomer with the requisite electrophilic acceptor. The section delineates the oxidation‐state differences in the products, which is primarily derived from the differences in C3 substitution in the 1,4‐dipole/1,3‐diene component. There is also evidence for one mechanism over the alternative in some cases. The Scope and Limitations section details each annulation separately, which permits the direct comparison to provide context for which version might prove superior for a particular application. The authors have described the preparation of the 1,4‐dipole equivalents in specific cases, which include variations in the nucleophilic phthalide and homophthalide components and their reactions with a variety of acyclic and cyclic Michael acceptors (enones, cyclohexadienes, quinones, and arynes). A particularly notable feature of this section is the discussion of the knowledge gaps in each of the four processes, which enable future areas of investigation to be easily identified. The Applications to Synthesis section describes an expansive array of applications to the construction of particularly challenging and important natural products, which certainly highlights the utility of this approach as an enabling transformation. The targets illustrate why this process has become so important for preparing complex bioactive agents. The section on Comparison with Other Methods is primarily focused on the examination of other cycloaddition and annulation reactions that deliver similar adducts. The Tabular Survey organization follows the Scope and Limitations, wherein the specific type of annulation is listed separately to permit the reader to compare and contrast the kind of annulation of interest. A particularly interesting facet of this chapter is that one of the variants is named after our esteemed colleague, Dr. Steven M. Weinreb, who ironically served as the Responsible Editor for this chapter. Overall, this is an outstanding chapter on a particularly important and useful process that will be a valuable resource to the synthetic community.
This volume of Organic Reactions is dedicated to Dr. Debra D. Dolliver, who sadly passed away in January of this year. Debra joined Organic Reactions as a Processing Editor in 2018 and worked on many important chapters, including the Nozaki chapter in this volume. She quickly learned the organization's nuances and contributed to several of the previous volumes that have been published in recent years. We acknowledge her contributions to the series in her short tenure, and we offer our deepest condolences to her husband, Dr. Artie McKim. A more detailed obituary is included at the beginning of this volume written by Arty McKim and Kevin H. Shaughnessy. The obituary paints a picture of a talented and deeply caring individual. I was unaware that Debra was also an artist and specialized in watercolors. If you are interested, I recommend visiting her website, where there are some beautiful examples of landscapes, still life subjects, and her dogs (dolliverart.com). I also selected the quotation with the loss of Debra in mind, which is meant to pertain to the life cycle and the pain of losing individuals. The events of 2020 have brought the value of human life and the expectation of its longevity to the fore. We therefore honor Dr. Debra D. Dolliver in this volume and recognize her contributions to our profession; she is sadly missed.
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 Donna M. Huryn (Chapter 1) and Steven M. Weinreb (Chapter 2), who served as the Responsible Editors to marshal the chapters through the various phases of development. I am also deeply indebted to Dr. Danielle Soenen for her continued and 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 contributions of the authors, editors, and publisher. 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 the late Dr. Debra Dolliver (Processing Editor). I would also like to acknowledge Dr. Barry B. 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 Board of Directors for ensuring the enduring quality of Organic Reactions. The unique format of the chapters, in conjunction with the collated tables of examples, makes this series of reviews both unique and exceptionally valuable to the practicing synthetic organic chemist.
P. Andrew Evans
Kingston
Ontario, Canada
Dr. Debra D. Dolliver
1960–2021
Dr. Debra D. Dolliver was born and raised in Snyder, Texas. She earned a BA in English from the University of North Texas in 1985 and then returned to school to earn a BS in Chemistry in 1994 at Texas Woman's University. After earning a MS in Organic Chemistry at TWU, she enrolled in the PhD program in chemistry at the University of North Texas. Her dissertation was co‐directed by Prof. Michael McAllister from UNT and Prof. James Johnson at TWU. Her PhD research focused on the nucleophilic addition/elimination mechanisms of imidoyl halides and (Z)/(E)‐isomerization of N‐alkoxyimines.
After completing her PhD in 2001, Debra was hired as an instructor at Southeastern Louisiana University. In 2003, she was promoted to assistant professor at SELU where she rose through the ranks to full professor in 2014. Debra made significant contributions to the teaching, research, and service missions at SELU. She was recognized with the SELU President's Award of Excellence in teaching (2010) and in service (2014). She led several successful efforts to receive research instrumentation funding from the State of Louisiana and the National Science Foundation. Debra was also responsible for the Career Paths in the Physical Sciences (CAPPS) for several years. The CAPPS program exposed college and high school students to career opportunities in the sciences.
Debra Dolliver was an active mentor to undergraduate research students at SELU. Her research focused on the synthetic applications of imidoyl halides. Her group showed that these could be used in the stereoselective synthesis of N‐alkoxyimine products. Bisamidoximes synthesized using Dolliver's methodology were shown to have high activity against human breast, colon, and lung cancer cell lines. Debra's research was supported by grants from the ACS‐PRF and NSF, as well as internal and state funding sources. Debra's students gave nearly 100 presentations at chemistry conferences during her time at SELU and she published 9 papers with undergraduate coauthors. Her students went on to numerous chemistry PhD programs, including at Duke, Michigan, Purdue, and Washington, as well as students who went on to medical school or careers in the chemical industry.
In 2016, Debra retired from SELU and joined her husband, Dr. Artie McKim, in Tuscaloosa, Alabama, where he serves as Technical Director for Gaylord Chemical's DMSO plant. Debra served as an instructor at The University of Alabama from 2016–2018. She also used her English and chemistry training as a freelance science writer for clients in the chemical industry. In 2018, Debra joined Organic Reactions as a processing editor.
Debra was a talented artist specializing in watercolors of landscape and still life subjects. She, along with many members of her family, gained her passion for art from her mother. The family's artistic creations are displayed at dolliverart.com.
Debra Dolliver had an engaging and caring personality that made her a popular source of advice for students and colleagues. At our journal, Debra's skills and enthusiasm quickly made her a valued member of the editorial team. She will be deeply missed by her husband, Artie, her colleagues, and her former students.
CHAPTER 1ENANTIOSELECTIVE HYDROFORMYLATION
TOSHIKI TAZAWA, ANDREAS PHANOPOULOS, KYOKO NOZAKI AND DONNA M. HURYN
Department of Chemistry and Biotechnology, Graduate School of Engineering, The University of Tokyo, 7‐3‐1 Hongo, Bunkyo‐ku, Tokyo, 113‐8656, Japan
Edited by DONNA M. HURYN
CONTENTS
INTRODUCTION
Rhodium Complexes with Chiral Ligands
Platinum Complexes with Chiral Ligands
MECHANISM AND STEREOCHEMISTRY
General Catalytic Cycle
Regioselectivity‐Determining Step
Enantioselectivity‐Determining Step
SCOPE AND LIMITATIONS
Classification of Substrates
Enantioselective Hydroformylation of Vinyl Arenes (Styrene, Substituted Styrenes, Vinylnaphthalene, Substituted Vinylnaphthalenes, and Vinyl Heteroarenes)
Enantioselective Hydroformylation of Aliphatic Acyclic Alkenes
Enantioselective Hydroformylation of Heteroatom‐Substituted Acyclic Alkenes
Enantioselective Hydroformylation of α,β‐Unsaturated Carbonyl Compounds
Enantioselective Hydroformylation of Allylic‐ and Homoallylic‐Substituted Acyclic Alkenes
Enantioselective Hydroformylation of Conjugated Dienes
Enantioselective Hydroformylation of Cyclic Alkenes
APPLICATIONS TO SYNTHESIS
1β‐Methylcarbapenem
2‐Methyl‐4‐aminobutanol
(+)‐Ambruticin
Tedanolide C
COMPARISON WITH OTHER METHODS
β‐Chiral Aldehyde Syntheses
α‐Chiral Aldehyde Syntheses by Chiral Auxiliary Group Strategies
α‐Chiral Aldehyde Syntheses by Intramolecular α‐Alkylation and α‐Arylation
α‐Chiral Aldehyde Syntheses by Intermolecular α‐Allylation
α‐Chiral Aldehyde Syntheses via Hydroboration
Hydrocarbohydroxylation and Hydrocarbalkoxylation (Hydroesterification)
Hydrocyanation
EXPERIMENTAL CONDITIONS
Carbon Monoxide
Hydrogen Gas (H
2
)
Syngas (CO/H
2
)
EXPERIMENTAL PROCEDURES
(
R
)‐2‐Phenylpropanal [Rhodium‐Catalyzed, Enantioselective Hydroformylation of Styrene (a Vinyl Arene)].
(α
R
)‐α‐Methyl‐3‐furanacetaldehyde [Rhodium‐Catalyzed, Enantioselective Hydroformylation of 3‐Vinylfuran (a Vinyl Heteroarene)].
(
S
)‐2‐Methylhexanal [Rhodium‐Catalyzed, Enantioselective Hydroformylation of 1‐Hexene (an Aliphatic Acyclic Alkene)].
(
S
)‐Acetic Acid 1‐Methyl‐2‐oxo‐ethyl Ester [Rhodium‐Catalyzed, Enantioselective Hydroformylation of Vinyl Acetate (a Heteroatom‐Substituted Acyclic Alkene)].
(
S
)‐
N
,
N
‐Diethyl‐2‐methyl‐3‐oxopropanamide [Rhodium‐Catalyzed, Enantioselective Hydroformylation of
N
,
N
‐Diethylacrylamide (an α,β‐Unsaturated Carbonyl Compound)].
(
R
)‐3‐Methyl‐4‐oxobutanenitrile [Rhodium‐Catalyzed, Enantioselective Hydroformylation of Allyl Cyanide (an Allylic Acyclic Alkene)].
(
R
)‐2‐(1‐Cyclohexenyl)propanal [Rhodium‐Catalyzed, Enantioselective Hydroformylation of 1‐Vinylcyclohexene (a Conjugated Diene)].
exo
‐2‐Norbornanecarbaldehyde [Platinum‐Catalyzed, Enantioselective Hydroformylation of Norbornene (a Cyclic Alkene)].
TABULAR SURVEY
Chart 1. Catalysts and Ligands Used in the Tables
Table 1A. Enantioselective Hydroformylation of Styrene
Table 1B. Enantioselective Hydroformylation of Substituted Styrenes
Table 1C. Enantioselective Hydroformylation of Vinyl Naphthalene and Substituted Vinyl Naphthalenes
Table 1D. Enantioselective Hydroformylation of Vinyl Heteroarenes
Table 2. Enantioselective Hydroformylation of Aliphatic Acyclic Alkenes
Table 3A. Enantioselective Hydroformylation of Vinyl Esters
Table 3B. Enantioselective Hydroformylation of Other Heteroatom-Substituted Acyclic Alkenes
Table 4. Enantioselective Hydroformylation of α,β-Unsaturated Carbonyl
Compounds
Table 5A. Enantioselective Hydroformylation of Allyl Cyanide
Table 5B. Enantioselective Hydroformylation of Other Allylic or Homoallylic Alkenes
Table 6. Enantioselective Hydroformylation of Conjugated Dienes
Table 7. Enantioselective Hydroformylation of Cyclic Alkene
References
INTRODUCTION
Hydroformylation is a general term used to describe the addition of both a hydrogen and a formyl group to an unsaturated bond, most commonly an alkene. In a typical hydroformylation reaction, alkenes react with carbon monoxide and hydrogen to form aldehydes (Scheme 1). The production of aldehydes from alkenes via hydroformylation annually amounts to the global production of more than 10 million tons of so‐called “oxo” products.1 As such, it is one of the most extensively studied homogeneous catalytic processes in both academia and industry. When carbon monoxide reacts with an appropriately substituted alkene to form a branched chiral aldehyde, a new stereocenter is generated, and indeed, enantioselective hydroformylation has attracted considerable attention, as chiral aldehydes are important intermediates for pharmaceuticals, agrochemicals, flavors, fragrances, and other fine chemicals.2 Furthermore, chiral aldehydes can be easily converted into alcohols, amines, and carboxylic acids and their derivatives, all of which are useful intermediates for the synthesis of biologically active compounds and for further synthetic transformations.3, 4
Scheme 1
The most common problem encountered during hydroformylation is over‐reduction of the initial aldehyde products to generate alcohols. For instance, many hydroformylation catalysts are also effective hydrogenation catalysts, and in the presence of excess hydrogen gas, the aldehyde is susceptible to further reaction. The simultaneous control of chemo‐, regio‐, and enantioselectivity in hydroformylation reactions has been challenging, as catalysts that ensure high selectivity in one aspect often afford poor selectivity in others. When the control of these factors is coupled with the desire for high yields and fast reaction rates, the number of catalysts that can perform enantioselective hydroformylation remains limited for both industrial and academic applications. Nevertheless, recent developments have resulted in improved hydroformylation catalysts that provide very good control of chemo‐ and regioselectivity, while also furnishing highly enantiomerically enriched aldehydes.
In general, transition‐metal catalysts are required for hydroformylation reactions. The first highly enantioselective example of asymmetric hydroformylation was reported in the early 1990s and used styrene as the substrate with a platinum/tin/phosphorus‐ligand system as the catalyst (Scheme 2). In contrast, the related rhodium complexes, which are typically the metal of choice for hydroformylation, gave disappointing results from a preparative standpoint.5, 6 Nevertheless, the platinum catalysts have several disadvantages, including low reaction rates and low regioselectivity for branched aldehydes, as well as issues with competing substrate hydrogenation (i.e., low chemoselectivity). More recently, rhodium/chiral‐phosphorus‐ligand systems have been developed to attain high conversions to aldehydes, with concomitant high regioselectivities (branched/linear ratios) and enantioselectivities.
Scheme 2
In the context of the substrates, terminal alkenes are the most widely studied because the double bond is more sterically accessible. Internal alkenes can also be used but exhibit slower rates from the increased stability of the double bond and the less favorable coordination insertion due to steric shielding. Additionally, internal alkenes often provide poor regioselectivity because both carbons often possess similar stereoelectronic properties.
Certain functional groups that are substituted alpha to the double bond may be used for enantioselective hydroformylation, because they show an intrinsic preference to form chiral branched aldehydes. In general, monosubstituted alkenes with an α‐aryl or α‐ester functional group are widely used (vide supra), but 1,2‐disubstituted alkenes with these functional groups can also be employed, but they exhibit slower rates of reaction. Styrene and vinyl acetate are often used as benchmark substrates to evaluate new catalysts, since these compounds form unusually stable branched rhodium–alkyl species compared to their linear analogues (see the “Regioselectivity‐Determining Step” section for more details). The branched rhodium–alkyl species required to generate the desired stereogenic centers from these substrates is unusually stable compared to the linear counterpart, thereby providing a favorable starting point for ligand and catalyst evaluation.
Enantioselective, catalytic hydroformylations generally employ homogeneous transition‐metal catalysts, such as rhodium or platinum complexes with chiral ligands. Rhodium catalysts are more reactive, and are therefore preferred over platinum complexes. In order to improve chemo‐, regio‐, and enantioselectivity, a variety of chiral ligands have been developed, the majority of which are bidentate ligands that incorporate two coordinating phosphorus moieties. Phosphorus ligands can be classified according to the three atoms that are attached to the central phosphorus: phosphine (P–C,C,C), phosphite (P–O,O,O), phosphinite (P–C,C,O), phosphonite (P–C,O,O), phosphoramidite (P–N,O,O), and phosphorodiamidite (P–N,N,O). Although diphosphines, diphosphites, and phosphine–phosphites have historically been used as ligands for enantioselective hydroformylation, newer types of phosphorus ligands, including phosphine–phosphorodiamidites, phosphine–phosphoramidites, phosphine–phosphonites, and diphosphonites, have been developed in the last decade.7–10
Although homogeneous catalysts are most frequently used, immobilized heterogeneous catalysts are more convenient in terms of product separation and catalyst recycling. Several examples of polymer‐supported catalysts11–15 and catalysts immobilized on SiO216 or mesoporous materials such as MCM‐4117 have been reported.
Rhodium Complexes with Chiral Ligands
In general, the most successful rhodium‐based hydroformylation catalysts feature at least one phosphorus atom directly bonded to non‐carbon atoms (phosphites, phosphoramidite, phosphorodiamidite and phosphonites). A common backbone motif among successful ligands is a binaphthyl moiety (Figure 1). Although the binaphthyl motif does not contain a stereogenic atom, it has axial chirality because of restricted rotation (atropisomerism) about the naphthyl–naphthyl bond. One of the most efficient phosphine–phosphite ligands for asymmetric hydroformylation of various alkenes that incorporates binaphthyl moieties is (R,S)‐BINAPHOS, which can work effectively at substrate/catalyst molar ratios (S/C) as low as 5000 (Scheme 3).18 The (R,S)‐BINAPHOS–rhodium(I) catalyst affords branched aldehydes with high conversion and good regio‐ and enantioselectivity for several substrates, including styrene and vinyl acetate.
Figure 1 The binaphyl moiety featuring two linked naphthal groups.
The types of ligands that tend to work well with rhodium complexes for enantioselective hydroformylation are not limited to phosphine–phosphite structures; for example, diphosphite 1, derived from homochiral (2R,4R)‐pentane‐2,4‐diol, provides a product with 93.5:6.5 er using styrene as the substrate.19 In some cases, phosphine ligands are also highly effective despite being less prevalent than phosphites, the latter of which are more capable of maintaining catalytic activity at the low temperatures favored by asymmetric hydroformylation. For instance, BisDiazaphos ligand 2, a diphosphine ligand, achieves high regio‐ and enantioselectivity for styrene20, 21 and other substrates, including 1,2‐disubstituted alkenes.22
Platinum Complexes with Chiral Ligands
Platinum‐catalyzed asymmetric hydroformylation reactions suffer from lower conversion compared to their rhodium counterparts and generally require a cocatalyst, such as tin(II) chloride, to activate the metal center. Platinum/tin systems show a higher tendency for alkene isomerization and undesirable hydrogenation of the starting material in comparison to their rhodium analogues.23 In general, the same ligand scaffolds can be utilized for either rhodium or platinum, making rhodium the current metal of choice when evaluating new ligands.
Scheme 3
This review covers the literature on enantioselective hydroformylation through June 2020 and discusses representative catalysts and chiral ligands. The general catalytic cycle proposed in the literature is described, as well as how it applies to typical substrates. The Tabular Survey includes all examples in the literature through June 2020, excluding those with extremely low er (<60:40) or low conversion (<20%).
Many excellent reviews on enantioselective hydroformylation have been reported, and the reader is also directed to these accounts.3, 7, 9, 24–33
MECHANISM AND STEREOCHEMISTRY
General Catalytic Cycle
The generally accepted mechanism for rhodium‐catalyzed hydroformylation is shown in Scheme 434 which is consistent with Wilkinson's so‐called dissociative mechanism.35–37 A greater understanding of the mechanism has been made possible through meticulous observations and structural characterization of various intermediates and catalyst resting states by in situ spectroscopic techniques, including high‐pressure IR and NMR (HP‐IR and HP‐NMR, respectively).27, 28
Scheme 4
When triphenylphosphine is used as the ligand, a common starting complex is RhH(CO)(PPh3)3 (3; L = PPh3). Under 1 bar of carbon monoxide, 3 is converted to complexes 4a and 4b (via 5a/b), which contain either two phosphine ligands in equatorial positions (complex 4b) or one phosphine ligand in an apical position and the other in an equatorial position (complex 4a). Dissociation of L from 3 or equatorial CO from 4 leads to the square‐planar intermediates 5a and
