Asymmetric Functionalization of C-H Bonds (RSC Catalysis, 25, Band 25) - Hardcover

Hardcover

ISBN 10: 1782621024 ISBN 13: 9781782621027

Verlag: Royal Society of Chemistry, 2015

Inhaltsangabe

Asymmetric C-H direct functionalization reactions are one of the most active and fascinating areas of research in organic chemistry due to their significance in the construction of molecular complexity without pre-activation, and the step economy and atom economy features in potential synthetic application. Distinguishing the reactivity among numerous C-H bonds in one single molecule represents one of the most challenging issues in organic synthesis and requires precise reaction design. As such, this field is now receiving increasing attention from researchers.

This book provides the first comprehensive review of this field, summarizing the origin, mechanism, scope and applications of the asymmetric C-H bond functionalization reaction. It covers organocatalytic reactions and transition-metal-catalyzed reactions, as well as asymmetric C-H functionalization reactions not described in other books.

Written by a leading expert in this field, the book is ideal for postgraduates and researchers working in organic synthesis, catalysis, and organometallic chemistry.

Über diesen Titel

Über die Autorin bzw. den Autor

Shu-Li You is Professor of Chemistry at the Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, China. His research interests mainly focus on enantioselective direct C-H bond functionalization and catalytic asymmetric dearomatization (CADA) reaction. Professor You has received numerous awards and is a member of the Advisory Board for several journals, including Chemical Society Reviews, Chemical Communications, Organic & Biomolecular Chemistry, and ACS Catalysis.

Von der hinteren Coverseite

Asymmetric C-H direct functionalization reactions are one of the most active and fascinating areas of research in organic chemistry due to their significance in the construction of molecular complexity without pre-activation, and the step economy and atom economy features in potential synthetic application. Distinguishing the reactivity among numerous C H bonds in one single molecule represents one of the most challenging issues in organic synthesis and requires precise reaction design. As such, this field is now receiving increasing attention from researchers.

This book provides the first comprehensive review of this field, summarizing the origin, mechanism, scope and applications of the asymmetric C-H bond functionalization reaction. It covers organocatalytic reactions and transition-metal-catalyzed reactions, as well as asymmetric C-H functionalization reactions not described in other books.

Written by a leading expert in this field, the book is ideal for postgraduates and researchers working in organic synthesis, catalysis, and organometallic chemistry.

Aus dem Klappentext

Asymmetric C-H direct functionalization reactions are one of the most active and fascinating areas of research in organic chemistry due to their significance in the construction of molecular complexity without pre-activation, and the step economy and atom economy features in potential synthetic application. Distinguishing the reactivity among numerous C H bonds in one single molecule represents one of the most challenging issues in organic synthesis and requires precise reaction design. As such, this field is now receiving increasing attention from researchers.

This book provides the first comprehensive review of this field, summarizing the origin, mechanism, scope and applications of the asymmetric C-H bond functionalization reaction. It covers organocatalytic reactions and transition-metal-catalyzed reactions, as well as asymmetric C-H functionalization reactions not described in other books.

Written by a leading expert in this field, the book is ideal for postgraduates and researchers working in organic synthesis, catalysis, and organometallic chemistry.

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Asymmetric Functionalization of C-H Bonds

By Shu-Li You

The Royal Society of Chemistry

Copyright © 2015 The Royal Society of Chemistry
All rights reserved.

ISBN: 978-1-78262-102-7

Contents

Chapter 1 Asymmetric C — H Bond Insertion Reactions Wen-Ting Wu, Ze-Peng Yang, and Shu-Li You, 1, 
Chapter 2 Asymmetric Cross-Dehydrogenative Coupling (CDC) Reactions Shou-Guo Wang and Shu-Li You, 67, 
Chapter 3 Asymmetric Oxidative Biaryl Coupling Reactions Chao Zheng and Shu-Li You, 92, 
Chapter 4 Asymmetric [1,5]-Hydride Transfer Reactions Xiao-Wei Liang, Chao Zheng, and Shu-Li You, 126, 
Chapter 5 Asymmetric Functionalization of C — H Bonds via a Transient Carbon–Metal (C — M) Species De-Wei Gao, Jun Zheng, Ke-Yin Ye, Chao Zheng, and Shu-Li You, 141, 
Chapter 6 Asymmetric Friedel–Crafts Alkylation Reactions Qiang Kang and Shu-Li You, 214, 
Chapter 7 N-Heterocyclic Carbene-Catalyzed Asymmetric Functionalization of Aldehyde C — H Bonds Yi Li and Shu-Li You, 283, 
Chapter 8 Asymmetric Hydroacylation Reactions Qing-Long Xu and Shu-Li You, 358, 
Chapter 9 Asymmetric Hydrovinylation Reactions Qing-Long Xu and Shu-Li You, 384, 
Subject Index, 405, 

CHAPTER 1

Asymmetric C — H Bond Insertion Reactions

WEN-TING WU, ZE-PENG YANG, AND SHU-LI YOU

1.1 C — H Bond Insertion by Metal Carbenoids

1.1.1 Introduction

It has been recognized for over 70 years that C — H bond functionalization can be realized through carbene insertion reactions. In recent years, many outstanding works including asymmetric reactions have appeared in this area.

Considering metal carbenoid-induced C — H bond insertions, there exists a general pattern, as shown in Scheme 1.1. The catalytic cycle is initiated by a metal complex via the decomposition of diverse carbene precursors (such as diazo compounds) to deliver a transient metal carbenoid intermediate in situ. Subsequently, the highly reactive metal carbenoid intermediate inserts into the C — H bond to afford the corresponding product and readily regenerates the metal complex to complete the catalytic cycle. Note that the metal atom is not thought to interact with the C — H bond directly. Moreover, since the transient metal carbenoid intermediate is highly reactive, the reaction conditions are typically mild and pH neutral, which renders this method compatible with a range of functional groups, like halides, triflates, and boronates.

However, the extraordinary reactivity of the carbenoid intermediates, in general, also makes them open to many possible reaction scenarios. Thus, reactivity control has been the essential need when working towards a synthetically useful methodology. Crucial breakthroughs are beginning to be made for the intramolecular approach and a handful of reviews have summarized the progresses on this topic. For intermolecular reactions, reactivity control is more challenging. Besides the intrinsic selectivity of diverse substrates, the key to solving this problem is being able to rely on the metal carbene precursors which, in general, determine the reactivity of the generated metal carbenoid intermediates. Along with the involvement of carbene precursors, especially the diazo compounds, the reactivity of metal carbenoid intermediates can be tunable, and thus an intermolecular approach can be achieved. According to the characteristics of the substituents on the carbene precursors, they can be classified into three major groups: acceptor carbenoid, acceptor/acceptor carbenoid, and donor/acceptor carbenoid (Figure 1.1). The electrophilic properties of the substituents at the metallo-carbenoid carbon center play a significant role in the reactivity and selectivity of the insertion reaction. Generally, an electron-withdrawing group, typically a carbonyl moiety, causes the carbenoid intermediate to be highly electrophilic and reactive, while an electron-donating group stabilizes the carbenoid intermediate. As far as acceptor carbenoids and acceptor/acceptor carbenoids are concerned, an electron-withdrawing group can both make the carbene precursor too stable to be decomposed by a metal complex and render the carbenoid intermediate highly reactive and susceptible to other competing processes. In that case, it is not so hard to understand they are apt to dimerization or hydride transfer to form zwitterionic intermediates, which can be overcome by intramolecular design. However, the donor/ acceptor carbenoids, as late arrivals to the field of metal carbenoid chemistry, revolutionized the situation dramatically and show great potential in highly selective intermolecular C — H bond functionalization; this is because the donating groups present, such as vinyl and aryl, can stabilize the carbenoid through resonance. Meanwhile, the aryl and vinyl groups also make the diazo precursors stable. In this case, highly active catalysts are required to effectively decompose this type of diazo compounds.

Rh and Cu complexes are commonly employed in metal carbenoid-involved asymmetric C — H bond functionalization while chiral catalysts based on Ir, Ru, and Fe as well as Lewis acids came into this area recently. This section aims to introduce the recent developments in asymmetric C — H bond functionalization achieved by metal carbenoids.

1.1.2 C — H Bond Insertion by Rh Carbenoids

Rh-catalyzed asymmetric C — H bond functionalization via a carbene insertion reaction was extensively documented in the early days, especially the intramolecular reactions. Thanks to enormous efforts from the groups of Davies and Doyle, asymmetric intramolecular C — H bond insertion by Rh carbenoids has become a reliable methodology and has been employed frequently in the total synthesis of complex natural products.

One important advantage of the intermolecular carbene insertion reactions is that simple starting materials can be employed and accordingly there is no need for the construction of complex substrates in advance. However, the intermolecular process requires a delicate balance between electronic and steric effects for metal carbenoids. On the other hand, there are several obstacles to be overcome, including chemo-, regio-, and enantioselectivity. Fortunately, great efforts have been devoted in the past decade and a series of carbene precursors and chiral Rh catalysts have been developed, so satisfactory yields and ee can be obtained in some catalytic systems. Generally, suitable carbene precursors, such as donor/acceptor diazo compounds, could reduce the chance of side product formation due to carbene dimerization. On the other hand, the dirhodium bridge caged within a "lantern" structure is thought to be essential to the success of dirhodium complexes in which two rhodium atoms are surrounded by four ligands in a nominal D4 symmetry. Both computational studies and characterization of dirhodium car-benoid intermediates suggested that the intermediate adopts a Rh — Rh=C framework. In another word, two rhodium atoms are bound to one carbene center, and the bonding scenario obeys the three-center orbital paradigm. As such, metal carbenoids derived from chiral RhII complexes and donor/ acceptor diazo compounds are routinely utilized.

Based on initial findings from the studies on achiral catalysts, chiral RhII complexes which have been developed for enantioselective C — H bond functionalization can be classified into four categories: RhII carboxylates, RhII carboxamidates, RhII phosphates, and...

Details zur Ausgabe

• Verlag: Royal Society of Chemistry
• Erscheinungsdatum: 2015
• Sprache: Englisch
• ISBN 10: 1782621024
• ISBN 13: 9781782621027
• Einband: Gebundene Ausgabe
• Anzahl der Seiten: 432
• Herausgeber: You Shu-Li
• Kontakt zum Hersteller: Nicht verfügbar
• Verantwortliche Person: gpsr@libri.de; gpsr@libri.de; ; Europaallee 1; Bad Hersfeld; 36244; Deutschland