Recent Advances in Denitrogenative Reactions of Pyridotriazoles
Ilya P. Filippov, Gleb D. Titov, Николай В. Ростовский
Abstract
Abstract Diazo compounds display versatile reactivity and therefore are widely used in organic synthesis. Diazo compounds bearing a 2-pyridyl or a related azine moiety on the diazo carbon exist in the form of fused 1,2,3-triazoles. In this short review, we summarize the recent advances in denitrogenative reactions of [1,2,3]triazolo[1,5-a]pyridines (‘pyridotriazoles’) and related fused 1,2,3-triazoles. Over the past decade, there has been a surge of activity in this field, with novel denitrogenative reactions of pyridotriazoles induced by metal compounds, light, and Brønsted and Lewis acids having been devised. As a result, heterocyclic compounds and functionalized α-picolines as well as bioactive molecules have been synthesized. In the review, emphasis is also placed on the mechanisms of the new reactions. 1 Introduction 2 Ring-Chain Isomerization of Pyridotriazoles 3 Metal-Catalyzed Reactions 3.1 Rh(II) Catalysis 3.2 Rh(III) Catalysis 3.3 Cu Catalysis 3.4 Pd Catalysis 3.5 Catalysis by Other Metals 4 Metal-Free Reactions 5 Conclusion