Norbornene in Organic Synthesis

Abstract The norbornene skeleton possesses an alkene functionality with a fixed conformation, and represents unique reactivity. The use of norbornene and analogues as substrates is overviewed; reactivities are discussed as well as the role of norbornenes as ligands assisting modern organic transformations. 1 Introduction 2 Synthesis of Substituted Norbornenes 2.1 Preparation of Functionalized Norbornenes by Deprotonation and Substitution Reactions 2.2 Preparation of Functionalized Norbornenes under Palladium-Catalyzed­ Reaction Conditions 2.3 Alkylation of Norbornene 2.4 Multistep Synthesis 3 Synthesis of Substituted Norbornanes 3.1 Three-Membered-Ring Formation 3.2 Formation of Four-Membered Rings 3.3 Five- and Six-Membered Ring Formation 3.4 Syntheses of Difunctionalized Norbornanes 4 Synthesis of Cyclopentanes 4.1 Oxidation Reactions 4.2 Ring-Opening Cross Metathesis (ROCM) 4.3 Ring-Opening Metathesis Polymerization (ROMP) 4.4 Palladium-Catalyzed Ring-Opening of Norbornene 5 Norbornene-Mediated Reactions 5.1 Palladium Insertion into Carbon–Halide Bonds 5.2 Palladium Insertion into N–H and C–H Bonds 5.3 Norbornene as Ligand in Mediated Reactions 6 Conclusion