Carbon-Heteroatom Bonds Lab Report

Chapter 1

Oxidative Coupling Reactions for Carbon-Carbon and Carbon-Heteroatom Bond Formations

1.1. Introduction

A coupling reaction in organic chemistry is the coupling of two hydrocarbon fragments via a metal catalyst. Coupling reactions are important methods to produce molecules through specific bond formations. In addition to the C–C bonds, C–heteroatom bonds are the basis of many organic structures. Many efforts have been made in the development of new and versatile methods for various bond constructions. The advancement of coupling technology greatly affects the developments of organic synthesis, host–guest chemistry, functional materials etc. A number of coupling reactions between nucleophiles and electrophiles have been explored and

Only recently the oxidative and reductive coupling (Scheme 1.1, B and C) have attracted much attention. As nucleophiles are the most abundant chemicals applied in organic synthesis and widely exist in nature, the oxidative coupling between two nucleophiles would be the most attractive synthetic approach. Normally, nucleophiles can be divided into four classes: MX, CM, CH, and XH (Figure 1.1). In the MX group, salts such as NaI and NaF are employed as reactants to form carbon-halogen bonds. In the C-M group, a metal reagent is employed that is compatible with different kinds of functional groups, hence making transition metal catalyzed reactions accessible. For example, Grignard reactions have been well studied, for their advantages that include high activity, high selectivity, and low cost, which all provide a convenient means of predominating the performance of compounds produced. With CH nucleophiles, oxidative cross-coupling reactions are known to take place. Since C–H bonds are ubiquitous in nature, direct C–C formation via C–H functionalization will reduce the pre activation of substrates. It is one of the most widely accepted green chemical processes, with environmentally benign byproduct such as H2O or H2O2 formed when employing O2 as an

First, most electrophiles such as organohalides are directly or indirectly synthesized from their corresponding nucleophiles. Therefore, the direct engagement of abundant nucleophiles will minimize the waste production and will reduce the prefunctionalization of substrates. Second, the development of methodologies based on the direct coupling of nucleophiles can provide novel disconnections for a target molecule, which would be otherwise inaccessible by traditional methods. Finally, the studies of coupling between two nucleophiles could potentially lead to the discovery of novel reactions, which would enrich our knowledge of C–C bond formation. Accordingly, bond formations between two nucleophiles have tremendous potential in the area of sustainable chemistry and will benefit