Photooxygenations and Self-Sensitizations of Naphthylamines: Efficient Access to Iminoquinones

Table 1

Optimization of the reaction conditions^a.

Entry	Solvent	Irradiation	Gas	Time (h)	Yield (%)^b
1	CCl4	UV lamp^c	Air	24	40^d
2	CCl4	Sunlight	Air	6	82^d
3	Acetone	Sunlight	Air	6	76
4	MeOH	Sunlight	Air	6	30
5	THF	Sunlight	Air	6	10
6	DMF	Sunlight	Air	6	20
7	Toluene	Sunlight	Air	6	50
8	MeCN	Sunlight	Air	6	78
9^e	MeCN	Dark	Air	6	nr
10	MeCN	Sunlight	O2	3	83
11	MeCN	Sunlight	N2	6	nr

^aReactions were carried out with 1a (2.0 mmol) in solvent (400 mL) for 6 h. ^bIsolated yields. ^c365 nm. ^dWith isolated yield of 2b. ^eAt 80°C.