Trichloroisocyanuric acid-mediated synthesis of 1,5-fused 1,2,4-triazoles from N-heteroaryl benzamidines via intramolecular oxidative N–N bond formation

Recent advances in the chemistry of 1,2,4-triazoles: Synthesis, reactivity and biological activities

“…Such targets can be readily obtained from 2hydrazinopyridines and various carboxaldehydes under mild electrolytic conditions. 19 An elegant alternative was recently developed by Bhatt et al 20 involving N-heteroaryl benzamidines as starting material and direct metal-free oxidative N-N bond formation promoted by trichloroisocyanuric acid (TCCA) (Scheme 6). This high yielding method takes advantage on a high functional group tolerance and a possible extension to pyrimidine substrates.…”

Emerging trends in the sustainable synthesis of N–N bond bearing organic scaffolds

“…The required 1,2,4-triazole product is obtained by further cleavage of the N -Cl bond, followed by deprotonation and rearomatization (Scheme 37). 72 Suzenet et al developed the synthesis of fused triazapentalene frameworks using the iodine( iii ) reagent, in the presence of a base, under mild reaction conditions. Amido anion A is produced in the catalytic pathway when the substrate is treated with the base.…”

Microwave-Mediated, Catalyst-Free Synthesis of 1,2,4-Triazolo[1,5-a]pyridines from Enaminonitriles

“…This cascade reaction proceeds via C-N coupling, followed by Boulton–Kartritzky rearrangement [ 27 ]. In 2022, Cao and coworkers reported the reaction of N -iminoisoquinolinium ylides with dioxazolone as an acyl nitrile source in the presence of copper acetate, providing 1,2,4-triazolo[1,5- a ]pyridines via C-H amidation and cyclization [ 28 ], and so on [ 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 ]. Despite the efficiency of these methods in several aspects, there are still some limitations, including the use of solvent in large quantities, longer reaction times, multistep processes, and, in several cases, the requirement for either metal or external catalysts, which will come out as chemical hazards.…”