α‐Diazo Sulfonium Triflates: Synthesis, Structure, and Application to the Synthesis of 1‐(Dialkylamino)‐1,2,3‐triazoles

Abstract

The one‐pot synthesis of a series of sulfonium salts containing transferable diazomethyl groups is described, and the structure of these compounds is elucidated by X‐ray crystallography. Under photochemical conditions, reaction of these salts with N,N‐dialkyl hydrazones affords 1‐(dialkylamino)‐1,2,3‐triazoles via diazomethyl radical addition to the azomethine carbon followed by intramolecular ring closure. The straightforward transformation of the structures thus obtained into mesoionic carbene–metal complexes is also reported and the donor properties of these new ligands characterized.

Trifluoromethyl Rhodium‐Carbynoid in [2+1+2] Cycloadditions

“…However, its equivalent, diazotrifluoroethyl radical [ A or B , CF 3 C(⋅)N 2 ] generated from hypervalent iodine (III) reagent via photoredox catalysis, was discovered in 2018 by Suero [4] . After that, the group of Alcarazo developed a general synthetic protocol towards α‐diazo sulfonium triflate, which could also be transformed into A or B under photochemical conditions [5] . Considering the importance of trifluoromethyl in medicinal chemistry [6] and our continued interest in fluorine chemistry, [7] we further applied this equivalent for visible‐light‐induced [3+2] cycloaddition in 2021 [8] .…”