Optimization of reaction conditions^a.

Entry	Cat.	Solvent	Temp. (°C)	Yieldb (%)
1	—	PhCl	120	65
2	Sm(OTf)3	PhCl	120	55
3c	Sm(OTf)3	PhCl	120	0
4	Cs2CO3	PhCl	120	0
5	Et3N	PhCl	120	0
6	AcOH	PhCl	120	0
7	—	Toluene	120	35
8	—	DMF	120	63
9	—	DMSO	120	45
10	—	1,4-Dioxane	120	Trace
11d	—	—	120	73
12d	—	—	110	75
13 d	—	—	100	85
14d	—	—	90	60
15d,e	—	—	100	86

^aReactions conditions: 1a (0.6 mmol), 2a (0.5 mmol), catalyst (10 mol% to 2a), solvent (1 mL), sealed tube, 10 h.

^bIsolated yield of pure product based on 2a.

^cCs₂CO₃ as base was added to the reaction.

^d1a (1.5 mmol), 2a (0.5 mmol), sealed tube, 10 h.

^eReaction time was 15 h.