Alkenylation of Imides and Activated Amides

The reaction of imides and activated amides with phosphoranes provides a simple route to enamides, bis[alkenyl]amines, and enamines. Experiments to determine the scope and limitations of these reactions are summarised in this review. Some of the results are taken from investigations with other aims. As well as the dependance on structure, configurational and tautomeric aspects of the reaction are described. The Wittig alkenylation of the imides is compared with other methods of alkenylation. 1. Introduction 2. Wittig Alkenylation of Imides 2.1. General Comments 2.2. Non-Stabilised Phosphoranes 2.3. Ethoxycarbonylmethylenetriphenylphosphorane and Cyanomethylenetriphenylphosphorane 2.3.1. Open Chain Imides 2.3.2. Five-Membered Ring Imides: Phthalimides, Succinimides, and Maleimides 2.3.3. Six-Membered and Larger Ring Imides 2.3.4. Bicyclic N-Bridgehead Imides 2.3.5. N-Acylimides 2.4. Benzoylmethylenetriphenylphosphorane 3. Alkenylation of Imides with the Wittig-Horner Reagent 4. Alkenylation of Activated Amides 4.1. N-Sulfonyllactams 4.2. N-Acylpyrroles 5. Conclusions