New Strategies for the Synthesis of Aliphatic Azides.

Aliphatic azides are a versatile class of compounds found in a variety of biologically active pharmaceuticals. These compounds are also recognized as useful precursors for the synthesis of a range of nitrogen-based scaffolds of therapeutic drugs, biologically active compounds, and functional materials. In light of the growing importance of aliphatic azides in both chemical and biological sciences, a vast array of synthetic strategies for the preparation of structurally diverse aliphatic azides have been developed over the past decades. However, to date, this topic has not been the subject of a dedicated review. This review aims to provide a concise overview of modern synthetic strategies to access aliphatic azides that have emerged since 2010. The discussed azidation reactions include (a) azidation of C-C multiple bonds, (b) azidation of C-H bonds, (c) the direct transformation of vinyl azides into other aliphatic azides, and (d) miscellaneous reactions to access aliphatic azides. We critically discuss the synthetic outcomes and the generality and uniqueness of the different mechanistic rationale of each of the selected reactions. The challenges and potential opportunities of the topic are outlined.