Electrocatalytic Intermolecular C(sp³)–H/N–H Coupling of Methyl N-Heteroaromatics with Amines and Amino Acids: Access to Imidazo-Fused N-Heterocycles

Abstract

An efficient NH 4 I-mediated intermolecular annulation of methyl N-heteroaromatics with amines/amino acids was developed by virtue of anodic oxidation, providing a variety of functionalized imidazo-fused N-heterocycles with good to excellent yields. The practicality of this protocol was demonstrated by the readily available starting materials, broad substrate scope, water tolerance, scalability, and the diverse transformations of the electrolysis product.

Photochemical and Electrochemical Strategies towards Benzylic C−H Functionalization: A Recent Update

“…Moreover, control studies using the electron-poor pyridine analogue, that failed at giving the desired product, showed that in this case oxidation of the sulphonamide happens first, hampering the overall reaction. The same year Wang and collaborators reported an electrocatalysed intermolecular synthesis of imidazofused N-heterocycles [83] (Scheme 39). Methyl N-heteroaromatics reacted with benzylamines or α-amino acids with the tandem formation of two CÀ N bonds to give the cyclised imidazoquinoline.…”

“…The same year Wang and collaborators reported an electrocatalysed intermolecular synthesis of imidazo‐fused N‐heterocycles [83] (Scheme 39). Methyl N ‐heteroaromatics reacted with benzylamines or α‐amino acids with the tandem formation of two C−N bonds to give the cyclised imidazoquinoline.…”

Oxidative Copper‐Catalyzed Regioselective Trifluoromethylation of Fused Imidazo[1,5‐a]‐N‐heteroarenes using Langlois Reagent

“…All the solvents were obtained from commercial sources and purified using standard methods. All 1 H, 13 C NMR spectra were recorded on Avance-300, Avance-400, and Avance-500 MHz Spectrometer. Chemical shifts (δ) are reported in ppm, using TMS (δ = 0) as an internal standard in CDCl 3 .…”

“…[12] Therefore, significant attention has been paid to the synthesis and functionalization of these structural units. [13] It is well-known that the installation of fluorine atoms or fluorine-containing groups into biologically active molecules increases their bioactivities. Hence, we turned our focus on the synthesis of biologically relevant trifluoromethylated imidazo[1,5-a]N-heteroarenes.…”

Electrochemical Synthesis of 1,2,4‐Thiadiazoles through Intermolecular Dehydrogenative S‐N Coupling

“…Initially, an iodide anion undergoes electro‐oxidation in a platinum anode, generating an iodine molecule, I 2 . Then 2‐aminopyridine ( 2 a ) tautomerizes to generate an imine form I , and reacts with iodine to give N ‐iodopyridin‐2‐amine ( II ), which resembles the reaction of 2‐methylquinolines with iodine . The active species II is subjected to a [3+2] annulation with an isothiocyanate 1 via deiodination and deprotonation to afford a 1,2,4‐thiadiazole 3 .…”