Computational Methods in Organometallic Catalysis. Yu Lan

for quantum chemical calculations.

      The description of organometallic structures and mechanisms is peppered with numerous calculations from the Lan group with relatively accurate density functionals. Part 2, the bulk of this book, is organized with a chapter for each of the most important metals used in organometallic chemistry: Ni, Pd, Pt, Co, Rh, Ir, Fe, Ru, Mn, Cu, Ag, and Au. The computational studies of the reactions of complexes of each of these metals are reviewed with great insights into mechanisms using computations.

The book will be a boon to organometallic chemists and computational chemists involved in the study of organometallic reactions. While a number of books on organometallic chemistry mechanisms are available, this is THE book describing the methods for computation and analysis of organometallic reactions using modern quantum mechanical methods.

      29 August 2020

       Kendall N. Houk

Preface

      A long time ago, when I first came into contact with science, I was fascinated by the unique charm of organic chemistry. The tetravalent carbon atoms and their tetrahedral structures impressed me with elegant simplicity. Through the broken and formation of covalent bonds, various new molecules that possess unique properties could be generated. By manipulating the reaction conditions, catalysts, and ligands in organic reactions, chemists can effectively synthesize plenty of complex natural product molecules and pharmaceutical molecules in high regioselectivity and enantioselectivity. When I was a teenager, I took every organic chemical reaction as a puzzle, and the reaction mechanism is like the answer to the puzzle. In this way, I found great pleasure in thinking about the mechanism of organic reactions. The development of organic chemistry also requires a comprehensive mechanistic understanding. Generally, a significant amount of information about reaction mechanisms could be obtained by experimental techniques. However, the experimental mechanistic study mainly focuses on the macroscopically observed experimental phenomena. Therefore, in many cases, pure experimental observation is not sufficient for revealing the complete reaction pathway and clarifying the origin of selectivity. During my doctoral study at Peking University, I was fortunate to work with my supervisor Professor Yun‐Dong Wu, from whom I learned how to use computational chemistry to investigate the organic reaction mechanisms. Theoretical calculations based on quantum mechanics, especially the density functional theory calculation, have constituted the most powerful tool for mechanistic study due to the development of supercomputer, computational theory, and corresponding software.

In the past several decades, one of the most important advances in organic chemistry has been the introduction of transition metal catalysts to organic synthesis. Transition metal species can react with organic compounds to generate intermediates that contain carbon–metal bonds. Subsequent conversion of these organometallic intermediates could enrich the synthetic approach toward new molecules. Different from organocatalysis, the organometallic catalysis usually goes through multiple steps and complicated catalytic cycles, which originated from the complex bonding pattern of organometallic catalysts and the variation of valance state of the central metal species. Thus, the utilization of theoretical calculation for understanding the reaction mechanism is imperative for the development of organic chemistry. My post‐doctoral research with Professor K. N. Houk was working with experimental chemists to explore the mechanism of organometallic reactions through the collaboration of theoretical calculation with experimental study. The promotion of theoretical study on experimental development could be summarized into “3D,” i.e. description, design, and direction. Based on the data obtained from experimental study, detailed descriptions of the organometallic reaction mechanisms could be fulfilled using theoretical calculation. The mechanistic study then provides further theoretical guidance for the rational design of new reactions, which points out the direction of experimental development.

      Over recent decades, massive experimental and theoretical investigations on organometallic catalysis have been reported. In those works, theoretical studies have been proved to be an indispensable technique for modern organic chemistry. Consequently, this book is written to summarize and generalize the theoretical advances in the mechanistic study of organometallic catalysis. This book comprises two parts, which are the general overview of organometallic catalysis and the computational studies of reaction mechanisms classified by transition metals. I hope this book could inspire the mechanistic studies of complex reactions for theoretical chemists, and enable a better understanding of reaction mechanisms for experimental chemists.

      29 July 2020

       Yu LanZhengzhou, P. R. China

Part I Theoretical View of Organometallic Catalysis

      It is time to write a book on computational organometallic chemistry.

      The first part of this book can be considered as the introduction to computational organometallic chemistry. It is a long history since organometallic catalysis has been applied in organic synthesis; however, the mechanism of those reactions is too complicated to understand. Indeed, computational chemistry provided a powerful tool to reveal the mechanism of organometallic reactions. During recent two decades, the combination of computational chemistry and organometallic chemistry has made a series of progress in mechanistic studies, which has led to a new discipline, computational organometallic chemistry.

      The first part would be composed of three chapters. In Chapter 1, a brief history of organometallics is given to reveal the significance of this chemistry. Computational chemistry, especially computational methods, is discussed in Chapter 2, which would be used in mechanism study of organometallic catalysis. Detailed processes for the familiar elementary reactions in organometallic catalysis discovered by theoretical calculations are summarized in Chapter 3.

1 Introduction of Computational Organometallic Chemistry

      This chapter provides a brief introduction of computational organometallic chemistry, which usually focuses on the reaction mechanism of homogeneous organometallic catalysis.

1.1 Overview of Organometallic Chemistry

      In this section, the historical footprint of organometallic chemistry is concisely given, which would help the readers better understand the role of computation in the mechanistic study of organometallic chemistry.

      1.1.1 General View of Organometallic Chemistry

      Creating new material is always entrusted with the important responsibility for the development of human civilization [1–3]. In particular, synthetic chemistry becomes a powerful tool for chemists, as it exhibits great value for the selective construction of new compounds [4–8]. Various useful molecules could be prepared by the strategies of synthetic chemistry, which provides material foundation, technological support, and drive force for science [9–20]. Synthetic chemistry is also the motivating force for the progress of material science, pharmaceutical science, energy engineering, agriculture, and electronics industry [21–41]. In this area, organic synthesis reveals broad interests from a series of research fields, which could target supply to multifarious functional molecules.

      The synthetic organic chemistry usually focuses on “carbon” to widen related research, which could afford various strategies for the building of molecular framework, functional group transformations, and controlling stereochemistry in more sophisticated molecules [9, 22, 42–50]. Therefore, selective formation of new covalent bond between carbon atom and some other atom involving nitrogen, oxygen, sulfur, halogen, boron, and phosphorus becomes one of the most important aims for synthetic organic chemistry. In particular, nucleophiles and electrophiles are important for the construction of new covalent bonds.

A nucleophile,