. 2017 May 23;2(5):2238–2247. doi: 10.1021/acsomega.7b00201

Table 1. Screening of Oxidants for the Synthesis of 3-Indolylquinone.

entry	oxidant	catalyst	yield^a ^b, %
1	air		NR
2	oxygen		NR
3	H₂O₂		NR
4	H₂O₂	MoO₃	10^a
5	H₂O₂	WO₃	15^a
6	H₂O₂	Fe₃O₄/PVP–PWA	10^a
7		Ag₂O	30^a/40^b
8	air	Ag₂O	25^a/45^b
9	oxygen	Ag₂O	27^a/41^b
10	H₂O₂	Ag₂O	94^a
11	H₂O₂	AgNO₃	35^a
12	DDQ		41^a/55^b
13	KBrO₃		10^a/30^b
14	K₄FeCN₆		NR
15	oxone		NR

Reactions were performed with 1:1 2-methylhydroquinone/2-methylindole, 0.1 g Fe₃O₄/PVP–PWA (141), 3 mmol oxidant, 10 mL of THF, and 20 mol % catalyst in 1 atm air/oxygen at RT for 2 h. NR, no reaction; isolated yield of 3-indolylquinone after column chromatography. Bold values represent maximum product yield under optimized reaction conditions.

The product 3-indolylhydroquinone is formed.