Table 1. Optimization of the directed three-component syn-vicinal-diarylation of alkene 1a with phenylboronic acids 2a and 4-methoxyphenyl iodide 3a ^a .

Entry	PdII cat.	Base	Solvent	Yield b [%]
1	Pd(OAc)2	K2CO3	HFIP (2 mL)	NR
2	Pd(OAc)2	Na2CO3	DCM/H2O/MeCN (1 : 0.2 : 0.1)	54
3	PdCl2	Na2CO3	DCM/H2O/MeCN (1 : 0.2 : 0.1)	44
4	Pd(PhCN)2Cl2	Na2CO3	DCM/H2O/MeCN (1 : 0.2 : 0.1)	69
5	(–)-SparteinePdCl2	Na2CO3	DCM/H2O/MeCN (1 : 0.2 : 0.1)	71
6	(–)-SparteinePd(OAc)2	Na2CO3	DCM/H2O/MeCN (1 : 0.2 : 0.1)	6
7	(Bipy)PdCl2	Na2CO3	DCM/H2O/MeCN (1 : 0.2 : 0.1)	60
8	PddppfCl2	Na2CO3	DCM/H2O/MeCN (1 : 0.2 : 0.1)	11
9	(–)-SparteinePdCl2	K2CO3	DCM/H2O/MeCN (1 : 0.2 : 0.1)	66
10	(–)-SparteinePdCl2	Cs2CO3	DCM/H2O/MeCN (1 : 0.2 : 0.1)	44
11	(–)-SparteinePdCl2	K3PO4	DCM/H2O/MeCN (1 : 0.2 : 0.1)	53
12 c	(–)-SparteinePdCl 2	Na 2 CO 3	DCM/H 2 O/MeCN (1 : 0.2 : 0.1)	83
13 c	(–)-SparteinePdCl2	Na2CO3	DCM/H2O/MeCN (1 : 0.1 : 0.1)	72
14 c	(–)-SparteinePdCl2	Na2CO3	DCM/H2O (1 : 0.2)	77
15 c	(–)-SparteinePdCl2	Na2CO3	DCM/CH3CN (1 : 0.1)	14
16 c	(–)-SparteinePdCl2	Na2CO3	DCM (2 mL)	18
17 c	(–)-SparteinePdCl2	Na2CO3	HFIP (2 mL)	NR
18 c d	(–)-SparteinePdCl2	Na2CO3	DCM/H2O/MeCN (1 : 0.2 : 0.1)	81
19 c e	(–)-SparteinePdCl2	Na2CO3	DCM/H2O/MeCN (1 : 0.2 : 0.1)	35

^aReactions were carried out by using Pd^II catalyst (10 mol%), ligand (0–20 mol%), base (0.3 mmol, 1.0 equiv.), 1a (0.3 mmol, 1.0 equiv.), phenylboronic acid 2a (2.0 equiv.), and 4-methoxyphenyl iodide 3a (3.0 equiv.) in the mixture of DCM/H₂O/CH₃CN (2 mL : 0.4 mL : 0.2 mL) for 24 h at 100 °C under a N₂ atmosphere.

^bIsolated yields.

^c(–)-Sparteine (20 mol%) was added.

^d(PhBO)₃ instead of 2a.

^ePhBNep instead of 2a.