Photocatalyzed redox-neutral decarboxylative alkylation of heteroaryl methanamines

Abstract

A redox-neutral decarboxylative radical–radical coupling reaction of heteroaryl methylamines with NHPI esters has been developed by employing a copper complex as a photocatalyst with blue LED irradiation.

Photocatalytic Redox-Neutral Approach to Diarylmethanes

“…In 2021, our group developed a radical–radical cross coupling reaction of NHPI esters with heteroaryl methylamines. This photocatalyzed redox-neutral alkylation reaction proceeded by one-electron reduction of NHPI esters and one-electron oxidation of heteroaryl methenamines in one photoredox catalytic cycle to form two radical intermediates that recombined subsequently to form new C–C bonds (Scheme , lower part) …”

Oxidative Cyclization of N‐Aryl Heteroaryl Methanamines with Arylalkenes

“…The effective synthetic methods for the modification of the skeleton are very high in demand. In 2021, we developed a redox‐neutral decarboxylative coupling reaction of this kind of compounds with N‐hydroxyphthalimide (NHPI) esters [11] . Encouraged by these advances, we questioned whether the oxidative Pavarov reaction of the N‐aryl heteroaryl methylamines with alkenes was possible.…”

“…According to Le Chatelier's principle, a temperature change, adding or removing of heat, shifts the chemical equilibrium toward the products or reactants. We found 60 °C was optimal for this transformation (Table 1, entries [10][11]. Solvents have a profound effect on the reaction outcome too (Table 1, entries [12][13][14][15].…”

Visible-light-driven C(sp3)–H alkylation of heterobenzylic amines via electron donor–acceptor complexes

“…In 2021, Huo and co-workers described a photocatalytic α-C(sp 3 )–H alkylation of 5-aryl-1,3,4-oxadiazole-2-methylamines, which required the addition of copper as a photoredox catalyst to reduce the redox-active esters via single electron transfer (SET). 16 Despite this progress, the transition-metal-free strategy for this transformation, while highly desirable, has still not been realized.…”