A covalent organic framework-catalyzed visible-light-induced three-component cascade synthesis of trifluoroalkyl and trifluoroalkenyl quinoxalin-2(1H)-one derivatives

Abstract

Herein, we report a visible-light-induced three-component cascade reaction of alkenes or alkynes with CF3SO2Na and quinoxalin-2(1H)-ones. In this reaction, a photoactive two-dimensional imine-linked covalent organic framework (2D-COF-5) was employed as...

Recent Advances in Visible Light‐Mediated Radical Fluoro‐alkylation, ‐alkoxylation, ‐alkylthiolation, ‐alkylselenolation, and ‐alkylamination

“…This approach employs a reductive SET of the NHC‐mediated acylazolium intermediate, a pathway that has not been well explored in the literature. Another multicomponent synthesis incorporating 22 is reported by Bu, Tian, Yang and coworkers [88] . By utilizing photoactive 2D Covalent Organic Frameworks (2D‐COF) with extended π‐conjugation, trifluoromethylated and trifluoroalkenylated quinoxalin‐2(1 H )‐one derivatives were formed under visible light.…”

“…Another multicomponent synthesis incorporating 22 is reported by Bu, Tian, Yang and coworkers. [88] By utilizing photoactive 2D Covalent Organic Frameworks (2D-COF) with extended π-conjugation, trifluoromethylated and trifluoroalkenylated quinoxalin-2(1H)-one derivatives were formed under visible light. This heterogeneous protocol enables a greener alternative to traditional photocatalyst-mediated radical generations; the 2D-COF was demonstrated by the authors to maintain comparable efficacy even after eight recycled runs.…”

Visible Light Induced Three‐Component 1,2‐Dicarbofunctionalization of Alkenes and Alkynes

“…Different research groups have approached using different methodologies to synthesize and functionalization of quinoxalin‐2(1 H )‐ones. In this regard, a new methodology was introduced by Yang and co‐workers [31] in 2022 (Scheme 13). They reported a 2D‐COF‐5 two‐dimensional imine‐linked covalent organic framework (COF) catalyzed visible‐light‐promoted three‐component cascade reaction involving alkenes/alkynes, sodium triflate and quinoxalin‐2(1 H )‐one derivatives in dioxane solvent.…”

Visible Light-Driven Flexible Synthesis of α-Alkylated Glycine Derivatives Catalyzed by Reusable Covalent Organic Frameworks

“…Photoactive covalent organic frameworks (COFs), possessing long π-conjugated systems, highly ordered layer structures, and considerable stability, have become a qualified heterogeneous photocatalyst for visible light-driven organic transformations, featuring additional sustainability and workup simplicity of these processes. − Various functional organic monomers bestow unlimited design ability on photoactive COFs, extending their catalytic power to various visible light-driven organic processes. , To date, many organic reactions, including oxidation, − reduction, , radical cyclization, − C–H bond functionalization, − E – Z isomerization, and cross-coupling, − were compatible with photoactive COFs, proceeding elegantly and fruitfully under visible light irradiation. COFs always played the following three primary roles in the above catalytic cycles.…”

“…Based on our prior studies of photoactive 2D-COF-catalyzed organic transformations, ,,,− we would like to report a β-ketoenamine-linked covalent organic framework (2D-COF-4) catalyzed visible light-driven α-C­(sp 3 )–H bond alkylation of glycine derivatives, shining our new understandings on photoactive COF applications (Scheme b). Given the appropriate redox potential of photoexcited 2D-COF-4 and the augmented blue light absorption of the reaction mixture (Figures S22 and S23, see the Supporting Information), the present visible light-driven α-C­(sp 3 )–H bond alkylation proceeded successfully and precisely, producing a wide range of α-alkylated glycine derivatives and peptides with good yields.…”