Table 1. Oxidative Coupling of Benzylamine Promoted by Various CuO Nanostructures^a.

entry	catalyst	temperature (°C)	time (h)	conv (%)
1	Cu-1 flake	100	4	5
2	Cu-1 flake	100	6	8
3	Cu-1 flake	100	10	23
4	Cu-1 flake	100	12	98
5	Cu-2 dandelion	100	12	55
6	Cu-3 short ribbon	100	12	72
7	Cu-2 dandelion	100	17	98
8	Cu-3 short ribbon	100	15	98
9	CuO bulk	100	12	3
10	Com-CuO	100	12	14
11b	Cu-1 flake	100	12	98

^aReaction conditions: benzylamine (0.2 mL, 1.83 mmol), CuO nanostructures (0.3619 mol % of Cu), O₂ balloon (1 atm pressure), determined by gas chromatography (GC) using diphenyl as the internal standard and confirmed by GC-(mass spectrometry) MS.

^bReaction was performed with benzylamine (2 mL, 18.3 mmol).