5-Iodo-1H-1,2,3-triazoles as Versatile Building Blocks

Abstract

Copper-catalyzed azide–alkyne cycloaddition is a useful tool for the synthesis of both 1,2,3-triazoles and 5-iodo-1H-1,2,3-triazoles starting from either terminal alkynes or iodoalkynes. 5-Iodotriazoles have been recognized as very useful building blocks for the synthesis of diverse 1,4,5-trisubstituted 1,2,3-triazoles. Synthetic application of 5-iodo-1,2,3-triazoles through the creation of a new C–C, C–heteroatom, or C–D(T) bond along with the application areas of both iodotriazoles and products of their modification including radiolabeled compounds are discussed.1 Introduction2 Synthetic Approaches to 5-Iodo-1H-1,2,3-triazoles3 5-Iodotriazoles in C–C Bond Formation3.1 Intermolecular C–C Cross-Coupling3.2 Intramolecular Cross-Coupling: Direct Arylation and C–I/C–I Homocoupling­3.3 Other Transformations4 5-Iodotriazoles in Radiolabeling, Halogen Exchange, and Heterocoupling Reactions5 Summary

Cu-catalyzed cycloaddition of aryl azides to 1-iodobuta-1,3-diynes: an experimental and quantum chemical study of unusual regiochemistry

“…1C). [28][29][30][31][32] It is important that the replacement of Cu(I)catalysts by Ru(II)-catalysts does not invert the regioselectivity, in contrast with terminal alkynes, and gives only 5-halogen-1,4disubstituted triazoles (Fig. 1C).…”

Divergent cyclization of 2-(5-iodo-1,2,3-triazolyl)benzamides toward triazole-fused lactams and cyclic imidates

“…The development of simple and efficient access to 5-iodotriazoles via Cu-catalyzed cycloaddition of azides to 1-iodoalkynes provided another universal approach to polysubstituted triazoles 17 due to the ease of further functionalization by Pd and Cu-catalyzed chemistry. Thus, the preparation of triazoles, fused to 5–9 membered rings, was accomplished in Heck reaction (Scheme 1A-6) 18 and multicomponent cascades involving post-Ullmann chemistry (Scheme 1A-7).…”

An FeCl3-catalyzed three-component reaction for the synthesis of β-(1,2,3-triazolyl)-ketones using DMF as a one-carbon source

“…1,2,3-Triazoles constitute a significant category of heterocyclic compounds extensively employed in diverse fields, including synthetic chemistry, pharmaceuticals, and functional materials. 1 Since the introduction of the concept of “click chemistry”, the synthesis of 1,2,3-triazoles has emerged as a prominent exemplar within this domain. 2 Over the years, several synthetic approaches for 1,2,3-triazoles, such as Cu- or Ru-catalyzed AAC (azide–alkyne cycloaddition) reactions 3 and SP (strain-promoted) AAC reaction, 4 have been developed.…”