Table 2.

Optimization of asymmetric dearomatization reaction conditions.

Entry	Substrate	Additive	Solvent (0.1 M)	Yield(%)a	Drb
1	5a	None	DMF	99c	1.6:1
2	5a	None	MeCN	78	1.3:1
3	5a	None	NMP	99	1.6:1
4d	5a	None	DMF	99	1.8:1
5d	5a	None	EtOAc	<5	Not determined
6	5a	BF3 (10 mol%)	DMF	61	1.4:1
7e	5a	Zn(OAc)2 (1.0 equiv.)	DMF	<5	Not determined
8e	5a	Mg(OAc)2 (1.0 equiv.)	DMF	52	1.5:1
9e	5a	LiOAc (1.0 equiv.)	DMF	65	1.4:1
10	5b	None	DMF	77	1.1:1
11	5c	None	DMF	99c	>20:1
12	5c	None	DMF	91%f	>20:1

Unless otherwise specified, to an oven-dried 10 mL-Schlenk tube equipped with a stir bar, was added 5 (0.1 mmol), photoredox catalyst (4CzIPN, 4.0 mg, 5 mol%), 2b (23.0 mg, 0.13 mmol), Cs₂CO₃ (32.0 mg, 0.1 mmol) and solvent (1.0 mL). The mixture was degassed by freeze-pump-thaw method, then sealed with parafilm. The solution was then stirred at rt under the irradiation of a 5 W blue LED strip for 36 h.

DMF dimethylformamide, NMP N-Methyl-2-pyrrolidone.

^a1H NMR yield.

^bDetermined by ¹H NMR.

^cIsolated yield.

^dCsOAc (1.0 equiv.) used as base.

^eNo base used.

^fReaction time: 24 h.