Eosin Y as a direct hydrogen-atom transfer photocatalyst for the C3-H acylation of quinoxalin-2(1H)-ones

Eosin Y mediated photo-catalytic C–H functionalization: C–C and C–S bond formation

“…In addition, protected and unprotected quinoxaline-2(1 H )-ones showed compatibility with the reaction (Scheme 32). 34…”

“…Zhan's group reported aerobic oxidative cyclization for synthesizing tetrahydroquinolines (35) using atmospheric oxygen and a metal-free photocatalyst. They carried out a onepot reaction between N,N-dimethylanilines (9) and maleimides (34) under visible light as an energy source with 2 mol% loading of eosin Y (relatively low loading) at room temperature. Substituted N,N-dimethylanilines (9) with -Br and -CH 3 groups reacted smoothly to afford the corresponding products in good yields.…”

Sunlight Induced and Recyclable g-C3N4 Catalyzed C-H Sulfenylation of Quinoxalin-2(1H)-Ones

“…Quinoxalin-2(1 H )-one is a privileged structural moiety, which exhibits various biological activities and pharmacological properties [ 1 , 2 ]. Consequently, a large number of 3-substituted quinoxalinones are prepared via direct C3–H functionalization of quinoxalin-2(1 H )-ones in recent years, mainly including alkylation [ 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 ], arylation [ 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 ], acylation [ 26 , 27 , 28 , 29 , 30 , 31 ], alkoxylation [ 32 , 33 , 34 , 35 ], sulfenylation [ 36 , 37 , 38 ], amination [ 39 , 40 , 41 , 42 , 43 , 44 ], phosphonation [ 45 , 46 , 47 , 48 , 49 ] and trifluoromethylation [ 50 , …”

Photo-redox catalyzed dehydrazinative acylation of N-heterocycles via Minisci reaction

“…Recently, eosin-Y has been reported as a direct hydrogen atom transfer photocatalyst to generate acyl radicals from aldehydes as radical precursors. 38 The generation of acyl radicals takes place very easily by oxidative cleavage using oxidants. Traditional Minisci reactions require the use of harsh conditions such as high temperature excess amounts of radical precursors, long reaction times and poor site selectivity.…”