Table 1.

Optimization of reaction conditions ^a.

Entry	Catalyst	Base	Solvent	Yield (%) b
1	CS@CuSO4	none	H2O	30
2	CS@Cu(OAc)2	none	H2O	22
3	CS@Cu(acac)2	none	H2O	41
4	CS@Cu(acac)2	Na2CO3	H2O	50
5	CS@Cu(acac)2	K2CO3	H2O	65
6	CS@Cu(acac)2	B1	H2O	40
7	CS@Cu(acac)2	B2	H2O	38
8	CS@Cu(acac)2	B3	H2O	86
9	CS@Cu(acac)2	B4	H2O	92
10	-	B4	H2O	NR
11	CS@Cu(acac)2	B4	DCM	NR
12	CS@Cu(acac)2	B4	THF	NR
13	CS@Cu(acac)2	B4	Et2O	NR
14	CS@Cu(acac)2	B4	Toluene	NR
15	CS@Cu(acac)2	B4	MeOH	25
16	CS@Cu(acac)2	B4	EtOH	8
17 c	CS@Cu(acac)2	B4	H2O	89
18 d	CS@Cu(acac)2	B4	H2O	91

^a Reaction conditions: substrate 2 (0.3 mmol), Me₂PhSi-B(pin) 1 (1.2 equiv.), catalyst (5 mol % Cu loading), base (6 mol %), H₂O (2 mL), room temperature, air, 12 h; ^b Isolated yield of product; ^c 2.5 mol % Cu loading was used; ^d Performed under Ar atomosphere.