Table 1.

Reaction conditions optimization^a

Entry	Catalyst	Yield (%)
1	PC–I	64
2	PC–II	0
3	PC–III	68
4	PC–IV	65
5	PC–V	47
6	PC–VI	57
7	PC–III	74b
8	PC–III	85b, c
9	PC–III	85b, c, d
10	PC–III	0e
11	–	0

PC photoredox catalyst, DCE 1,2-dichloroethane

^aReactions were performed with 1a (0.1 mmol), 2a (0.3 mmol), photocatalyst (2 mol%) in 1,2-dichloroethane (0.5 mL), irradiating with 15 W blue LEDs under an air atmosphere at room temperature for 16 h. Yields were determined by ¹H NMR using 1,1,2,2-tetrachloroethane as internal standard

^bUnder O₂ atmosphere

^cWith 4 Å molecular sieves

^d0.2  mol% photoredox catalyst was used

^eEither without irradiation or under N₂ atmosphere