Visible-light-promoted/PIFA-mediated direct C–H acylation of quinoxalin-2(1H)-ones with aldehydes

Abstract

With aldehydes as the radical precursors under visible-light irradiation, a simple and mild PIFA-mediated C–H acylation reaction of quinoxalin-2(1H)-ones has been achieved.

Photoredox Catalysis with Visible Light for Synthesis of Thioxanthones Derivatives

“…The Supporting Information is available free of charge at https://pubs.acs.org/doi/10.1021/acs.orglett.3c02253. Materials, instruments, synthetic procedures, measurements, detailed results including the 1 H NMR, 13…”

“…Additionally, we investigated by using phenyliodine(III) bis(trifluoroacetate) (PIFA) with undesirable yield (15%) (entries 4−7). 13 We further tried different photosensitizers as PCs phenanthraquinone (PQ) 14 and camphorquinone (CQ) 15 and investigated the yield of 1a in the presence of different oxidants (NH 4 ) 2 S 2 O 8 , SeO 2 , K 2 Cr 2 O 7 , and Ag 2 O (entries 8−15). Encouragingly, a significantly improved cyclization yield of 2a (76%) was achieved when using photosensitizer PQ as the catalyst and (NH 4 ) 2 S 2 O 8 as the oxidant in CH 3 CN.…”

“…According to the conditions reported by Wu’s group, the photoreactions for the synthesis of product 2a (ITX) were performed, which showed only 15% to 18% yield in different polar solvents (entries 1–3). Additionally, we investigated by using phenyliodine­(III) bis­(trifluoroacetate) (PIFA) with undesirable yield (15%) (entries 4–7) . We further tried different photosensitizers as PCs phenanthraquinone (PQ) and camphorquinone (CQ) and investigated the yield of 1a in the presence of different oxidants (NH 4 ) 2 S 2 O 8 , SeO 2 , K 2 Cr 2 O 7 , and Ag 2 O (entries 8–15).…”

Direct Access to Strained Fused Dihalo-Aziridino Quinoxalinones via C3-Alkylation Followed by Tandem Cyclization

“…The metal-mediated and metal-free approaches have been explored for the simple C3-alkylation of quinoxalinone either under thermal or photochemical conditions (Scheme a) . Recently, the C3-acylation of quinoxalinone has been achieved by utilizing α-oxo acids and aldehydes (Scheme a) . Other strategies such as C3-amination, amidation, alkoxylation, carboamylation, phosphonation, thiolation, silylation, and cynation have been also successfully demonstrated relying on photocatalysis, electrocatalysis, metal catalysis, and radical oxidative coupling reactions (Scheme a).…”

Ion recognition by 1,2,3‐triazole moieties synthesized via “click chemistry”

“…Cu(I) catalyst [28] enhances the reaction rate by almost 10 7 times in comparison with uncatalyzed Huisgen cycloaddition wherein no regioselective control yields 1,4-and 1,5-triazoles in nearly equal proportions. [29][30][31] Click chemistry has been extensively exploited in drug discovery and delivery, [32][33][34] photodynamic therapy, [35,36] solid-phase microextraction, [37] optical brightening agents, [38,39] biomedical applications, [40][41][42][43] virus-related research, [44][45][46] bioconjugation, [47,48] proteomics, [49,50] cellular bioimaging, [51][52][53][54] nanobiotechnology, [55] orthogonal spin labeling, [56] neoglycopolymer synthesis, [57] polymer chemistry, [58][59][60][61] ion sensing, [62,63] and so forth.…”