Table 1.

Optimization of the Suzuki–Miyaura Reaction between 2-Naphthyl tert-Butylcarbonate and 4-Methoxyphenylboronic Acid Using ^LNi^II _(o-tol)(Cl) (L = dppf, dippf, dcypf) as Precatalysts^a

entry	ligand	temp (°C)	time (h)	boronic acid (equiv)	catalyst loading(mol %)	water (equiv)	yield (%)
1	dppf	80	24	2.5	2.5	0	5
2	dippf	80	24	2.5	2.5	0	61
3	dcypf	80	24	2.5	2.5	0	>99
4	dcypf	80	4	2.5	2.5	0	>99
5	dcypf	80	2	2.5	2.5	0	90
6	dcypf	60	4	2.5	2.5	0	92
7	dcypf	40	4	2.5	2.5	0	31
8	dcypf	60	4	1	2.5	0	64
9	dcypf	60	4	1.5	2.5	0	74
10	dcypf	60	4	2	2.5	0	87
11	dcypf	60	4	2.5	0.5	0	31b
12	dcypf	60	4	2.5	1	0	57b
13	dcypf	60	4	2.5	2	0	74b
14	dcypf	60	4	2.5	2.5	50	91
15	dcypf	60	4	2.5	1.0	50	59

^aReaction conditions: 2-naphthyl tert-butylcarbonate (0.133 mmol), 4-methoxyphenylboronic acid (0.133 mmol, 1 equiv; 0.200 mmol, 1.5 equiv; 0.266 mmol, 2 equiv; 0.333 mmol, 2.5 equiv), K₃PO₄ (1.8 equiv relative to boronic acid), naphthalene internal standard (0.0665 mmol, 0.5 equiv), toluene (1 mL). Yields were determined by GC and are reported as the average of at least two trials.

^bThe reaction went to completion after 12 h of reaction time; however, the reactions at 0.5 and 1.0 mol % did not reach completion even after 24 h.