Photochemical Synthesis of Azaheterocycles

Synthetic organic photochemistry is a field that continues to offer unique routes to organic structures not typically accessed from thermal reactions. In this review, the photochemical synthesis of five-, six-, seven-, and eight-membered-ring azaheterocycles, as well as some aza-macrocycles, is discussed. The discussion will focus on methods where heterocycle formation occurs during or as a result of a photochemical event. Reaction mechanisms will be discussed also, as these provide a rationale for understanding the synthetic results. 1 Introduction 2 Five-Membered Rings 2.1 Cyclization Reactions 2.2 Cycloadditions 2.3 From Aromatic and Vinyl Azides 2.4 earrangements 2.5 Other Individual Methods 3 Six-Membered Rings 3.1 Cyclization Reactions 3.2 Isocyanide Insertions 3.3 Cycloadditions 4 Seven-Membered Rings and Larger 5 Conclusion