Table 1. Optimization Table for the Suzuki–Miyaura Cross-Coupling Reaction.

entrya	catalyst (mol %)	iodobenzene/base (mmol)	base	solvent	temp. (°C)	time (min)	isolated yield (%)
1	without catalyst	1:1.5	K2CO3	H2O	100	1440	trace
2	0.13	1:1.5	K2CO3	H2O	70	90	82
3	0.17	1:1.5	K2CO3	H2O	70	50	92
4	0.22	1:1.5	K2CO3	H2O	70	20	96
5	0.26	1:1.5	K2CO3	H2O	70	30	96
6	0.22	1:1.2	K2CO3	H2O	70	120	79
7	0.22	1:1.8	K2CO3	H2O	70	60	96
8	0.22	1:1.5	K2CO3	EtOH	reflux	60	80
9	0.22	1:1.5	K2CO3	EtOH/H2O (1:1)	reflux	50	86
10	0.22	1:1.5	K2CO3	DMF	100	360	82
11	0.22	1:1.5	K2CO3	DMF/H2O (1:1)	100	120	89
12	0.22	1:1.5	K2CO3	toluene	reflux	720	42
13	0.22	1:1.5	NaHCO3	H2O	70	120	76
14	0.22	1:1.5	K2CO3	H2O	50	120	72
15	0.22	1:1.5	K2CO3	H2O	100	20	90

^aReaction conditions: iodobenzene(1 mmol), phenylboronic acid (1.2 mmol), base (1.5 mmol), solvent (2 mL), and the Fe₃O₄@Guanidine-Pd (0.22 mol %) catalyst was agitated at 70 °C for 20 min.