Optimization table of reaction conditions^a.

Entry	Catalyst	Base	Solvent	Yieldb	erc
1	Pd(OAc)2	Cs2CO3	Toluene	85%	95  5
2	Pd(TFA)2	Cs2CO3	Toluene	80%	92  8
3	Pd(CH3CN)2Cl2	Cs2CO3	Toluene	70%	93  7
4	Pd(PEt3)2Cl2	Cs2CO3	Toluene	—	—
5	Pd(OAc)2	K2CO3	Toluene	70%	94  6
6	Pd(OAc)2	Ag2CO3	Toluene	68%	60  40
7	Pd(OAc)2	Na2CO3	Toluene	78%	85  15
8	Pd(OAc)2	Cs2CO3	DMF	—	—
9	Pd(OAc)2	Cs2CO3	Dioxane	—	—
10	Pd(OAc)2	Cs2CO3	1,2-DCE	70%	91  9
11d	Pd(OAc)2	Cs2CO3	Toluene	90%	95  5
12	Pd(OAc)2	—	Toluene	Trace	—
13e	Pd(OAc)2	Cs2CO3	Toluene	—	—
14d,f	Pd(OAc)2	Cs2CO3	Toluene	Trace	—
15d	Pd(OAc)2	Cs2CO3	DMSO	Trace	—

^aReaction conditions: 1a (0.2 mmol), 2a (0.3 mmol), Pd(OAc)₂ (5 mol%), ligand (20 mol%), base (1.5 eq.) and Cu(OAc)₂·H₂O (2.0 equiv.) at 60 °C in toluene (3.0 mL) under argon.

^bIsolated yields are of the product.

^cDetermined by HPLC analysis on a chiral stationary phase.

^dReaction conducted in the presence of 10 mol% Pd(OAc)₂.

^eReaction conducted in the absence of Cu(OAc)₂·H₂O.

^f15 equiv. of DMSO added.