Synthesis of 5-Iodo-1,2,3-triazoles from Organic Azides and Terminal Alkynes­: Ligand Acceleration Effect, Substrate Scope, and Mechanistic Insights

Abstract

An improved method has been developed for the preparation of 5-iodo-1,2,3-triazoles directly from organic azides and terminal alkynes by a reaction mediated by copper(I) and iodinating agents generated in situ. The major methodological advance of the current procedure is that it provides a high conversion and good iodo/proto selectivity with a broad range of substrates without using an excess of the alkyne, which was required in the previous method. The use of an accelerating ligand is essential to the success of reactions involving unreactive azides or alkynes. New mechanistic insights are provided, including the confirmation that a 1-iodoalkyne is formed as a key intermediate under the established conditions for the reaction.

Synthesis and biological evaluation of ciprofloxacin – 1,2,3-triazole hybrids as antitumor, antibacterial, and antioxidant agents

“…Elemental analysis was performed at the University of Jordan. Aryl azides(6c-f) were prepared from the reaction of corresponding aryldiazonium salts with sodium azide [ 13 ], while p -fluorbenzyl azide(9a) and m -fluorobenzyl azide(9b) were prepared from the reaction of their corresponding benzyl bromide with sodium azide [ 14 ]. Organic azides were used directly without further purification and stored in the freezer at −20 °C.…”

Luminescence and Stability of 1,4,5‐Triaryl‐1,2,3‐Triazoles

“…All compounds listed in Figure 2 were prepared based on the strategies depicted in Scheme 1. Diaryl-substituted 6-1A4B and 7-1B4A were prepared via the CuAAC reaction (step a in Scheme 1), [6,18] while the triaryl-substituted triazoles were synthesized via the formation of 5-iodotriazole from an azide and an alkyne (step b), [7,19,20] followed by a Suzuki reaction with an aryl boronic acid (step c). [8] Two compounds that carry the benzyl group on the N1 position (14-1Bn4A5B and 15-1Bn4B5A), and the triphenyl-substituted control compound 16-1P4P5P are also studied.…”

Copper(ii) complexes of N-propargyl cyclam ligands reveal a range of coordination modes and colours, and unexpected reactivity

“…Accordingly, a convergent route to 14 was developed (Scheme 4b), with a view that an increased yield could be achieved if the CuACC was conducted in the absence of the cyclam. Bromide 16 was formed in two steps from benzyl azide, 49 and in the critical step, used to alkylate cyclam 1 in good yield (71%). The spectroscopic properties of 14 were investigated alongside 9 for comparison.…”