Construction of 1,2,4-triazole-fused heterocycles via an amine oxidase-inspired catalyst

Abstract

1,2,4-Triazoles are ubiquitous in pharmaceuticals, natural products, coordination chemistry, agrochemicals, and material science research. Herein we report a practical regioselective synthesis of 1,2,4-triazoles utilizing an amine oxidase-inspired catalysis. An o-quino-enzyme...

Synthesis of Furo- and Thienoquinolines by Using an Amine Oxidase-Inspired Catalyst

“…An electron-withdrawing group on the aryl ring facilitates cyclization by increasing the electrophilicity of the imine. We propose, by analogy to our previous studies, 13a b that the secondary-amine intermediate 12ab′ undergoes oxidation by an addition–elimination mechanism. The reaction of 12ab’ with Fe(phd) 2 Cl 3 produces the hemiaminal intermediate V , which eliminates the product 3ab .…”

Molybdenum‐Catalyzed One‐Pot Multi‐Step Synthesis of N‐Polyheterocycles from Nitroarenes and Glycols

“…In 2016, Bhattacharya reported the synthesis of furo[3,2‐ c ]quinolines via the Pictet‐Spengler reaction of the o ‐(3‐furyl)anilines, which were obtained from the corresponding nitro derivatives, and an aldehyde catalyzed by FeCl 3 [41] . Moreover, Maji developed a new route for accessing furoquinolines from the corresponding 2‐(furan‐3‐yl)aniline with arylamines [12d] . However, most of these methods suffer from certain drawbacks, including multi‐step processes and tedious procedures.…”

Sequential, Electrochemical‐Photochemical Synthesis of 1,2,4‐Triazolo‐[4,3‐a]pyrazines

“…[8][9][10][11][12]14,25,26] Recently, Maji et al, published on the regioselective synthesis of,1,2,4-triazoles and 1,2,4-triazolo-[4,3-a]pyrazines using an o-quino-enzyme to catalyze the cyclization of hydrazine substituted heterocycles with primary amines in the presence of FeCl 3 as a Lewis acid cocatalyst and O 2 as an oxidant. [27] Although effective, these procedures require hydrazine, as well as a chlorinated starting material to obtain the desired heterocyclic starting material. An alternative route that avoids direct formation of the hydrazinesubstituted pyrazine via chlorinated precursors is via the ring opening of a 1,2,4-oxadiazole with ethylenediamine to obtain the hydrazine-substituted piperazine.…”