Ring Opening of Donor–Acceptor Cyclopropanes with N-Nucleophiles

Ring opening of donor–acceptor cyclopropanes with various N-nucleophiles provides a simple approach to 1,3-functionalized compounds that are useful building blocks in organic synthesis, especially in assembling various N-heterocycles, including natural products. In this review, ring-opening reactions of donor–acceptor cyclopropanes with amines, amides, hydrazines, N-heterocycles, nitriles, and the azide ion are summarized. 1 Introduction 2 Ring Opening with Amines 3 Ring Opening with Amines Accompanied by Secondary Processes Involving the N-Center 3.1 Reactions of Cyclopropane-1,1-diesters with Primary and Secondary Amines 3.1.1 Synthesis of γ-Lactams 3.1.2 Synthesis of Pyrroloisoxazolidines and -pyrazolidines 3.1.3 Synthesis of Piperidines 3.1.4 Synthesis of Azetidine and Quinoline Derivatives 3.2 Reactions of Ketocyclopropanes with Primary Amines: Synthesis of Pyrrole Derivatives 3.3 Reactions of Сyclopropane-1,1-dicarbonitriles with Primary Amines: Synthesis of Pyrrole Derivatives 4 Ring Opening with Tertiary Aliphatic Amines 5 Ring Opening with Amides 6 Ring Opening with Hydrazines 7 Ring Opening with N-Heteroaromatic Compounds 7.1 Ring Opening with Pyridines 7.2 Ring Opening with Indoles 7.3 Ring Opening with Di- and Triazoles 7.4 Ring Opening with Pyrimidines 8 Ring Opening with Nitriles (Ritter Reaction) 9 Ring Opening with the Azide Ion 10 Summary