Table 1. Optimization to Study the Effect of Various Catalysts and Oxidants^a.

entry	catalyst	oxidant	yield (%)b
1	PdCl2(PPh3)2	TBPB	traces
2	Pd2(dba)3	TBPB	38
3	PdCl2	TBPB	5
4	Pd(PPh3)4	TBPB	30
5	Pd(OAc)2	TBPB	55
6	Pd(TFA)2	TBPB	51
7	Co(acac)3	TBPB	traces
8	RuCl3·xH2O	TBPB	NRc
9	[RuCl2(p-cymene)]2	TBPB	NRc
10	[RhCl(cyclooctadiene)]2	TBPB	NRc
11	IrCl3	TBPB	traces
12	Pd(OAc)2	(NH4)2S2O8	NRc
13	Pd(OAc)2	K2S2O8	NRc
14	Pd(OAc)2	TBHP (aq)	17
15	Pd(OAc)2	TBHP (decane)	18
16	Pd(OAc)2	DTBP	traces
17	Pd(OAc)2	H2O2	NRc
18	Pd(OAc)2	(NH4)2S2O8 (6)	NRc,d
19	Pd(OAc)2	K2S2O8	NRc,d
20	Pd(OAc)2	O2	NR

^aReagents and conditions: a mixture of 1-methyl-3-phenylquinoxalin-2(1H)-one (1 mmol), phenylglyoxylic acid (3 mmol), catalyst (10 mol %), fluorescein dye (40 mol %), and oxidant (6 equiv) was stirred in water solvent at room temperature for 15 h under irradiation of 24 W blue LEDs.

^bIsolated yield.

^cNo reaction (starting material was present unreacted).

^dOxidants were taken along with AgNO₃.