Table 2. Direct Synthesis of Primary Amines from Vanillyl Alcohol and (NH₄)₂CO₃ Using Ni/Al₂O₃–SiO₂ As a Catalyst^a.

				selectivity/%
entry	catalyst amount/mg	sub. (mmol)/(NH4)2CO3 (mmol) ratio	conversion /%	2m	5m	4m	6m	3′m	dimers
1	100	0.5:1	83	52	2	3	0	19	23
2	100	0.25:1	87	54	0	2	1	25	27
3	100	0.5:2	54	50	1	2	0	23	23
4	200	0.5:2	>99	58 (40)b	2	4	0	16	20
5	50	0.5:2	34	56	1	2	0	19	22
6	400	1:4	>99	4	4	55	1	7	29

^aGeneral reaction conditions: general procedure 2, Ni/Al₂O₃–SiO₂ catalyst, vanillyl alcohol substrate, (NH₄)₂CO₃, 3 mL t-amyl alcohol, 140 °C, 18 h; conversion and selectivity were calculated by GC-FID.

^bIsolated yield by column chromatography.