Recyclable Carbon Nitride Nanosheet‐Photocatalyzed Aminomethylation of Imidazo[1,2‐a]pyridines in Green Solvent

Abstract

Comprehensive Summary An efficient and eco‐friendly carbon nitride nanosheet (NM‐g‐C3N4)‐catalyzed decarboxylative coupling reaction of imidazo‐fused heterocycles (i.e., imidazo[1,2‐a]pyridines, benzo[d]imidazo[2,1‐b]thiazole) with N‐phenylglycines in dimethyl carbonate (DMC) has been developed. The toxic solvents, external oxidants, and restricted reaction conditions could be effectively avoided in this powerful and sustainable protocol. Remarkably, NM‐g‐C3N4 could be straightforwardly recovered by simple centrifugation and recycled and reused at least 7 times without an obvious decrease in catalytic activity.

In Situ Synthesis of Cu3P/P‐Doped g‐C3N4 Tight 2D/2D Heterojunction Boosting Photocatalytic H2 Evolution†

“…[ 6‐7 ] However, pristine g‐C 3 N 4 is generally unfavorable for photocatalytic H 2 evolution owing to its severe charge recombination and the lack of reaction activity sites. [ 8‐9 ] Accordingly, diversiform modification strategies have been developed to improve the photo‐activity of g‐C 3 N 4 , such as morphology control, heterostructure construction, element doping, co‐catalyst loading, etc . [ 6 ] Among these modification methods, constructing heterostructures with other semiconductors has been widely illustrated.…”

Electrochemical Decarboxylative Coupling of N‐Substituted Glycines under Air: Access to C3‐Aminomethylated Imidazo[1,2‐a]pyridines

“…For example, in 2019, Zhu and Le's group reported the first example in the absence of photosensitizer under the irradiation of blue light with a long reaction time (16–35 h), but the substrates were limited to N ‐aryl glycines [20] . Subsequently, Yu and co‐workers disclosed that CsPbBr 3 with white light [21] and graphitic carbon nitride (g‐C 3 N 4 ) with blue light [22] are suitable systems to obtain C3 aminomethylated imidazo[1,2‐ a ]pyridines. In addition, with the utilization of copper triflate and excess manganese dioxide in Yang's work, the amino acids could be extended to tertiary amines, but the reaction required a relatively high temperature (up to 120 °C) [23] .…”

Recent Developments in the Photochemical Synthesis of Functionalized Imidazopyridines

“…The same team went one step further by improving the protocol in a greener way. In 2021, Lv and Yu established an eco-compatible carbon nitride nanosheet (NM-g-C 3 N 4 ), which could catalyze under blue-LED irradiation the aminomethylation of imidazopyridines [ 51 ]. To fulfill the criteria of green chemistry, dimethyl carbonate was employed this time as the reaction solvent.…”