Effect of catalyst loading on synthesis of 2,4,6-triphenylpyridine^a.

Entry	Catalyst loading (mol%)	Yieldb (%)
1	None	21
2	0.1	43
3	0.5	79
4	1	93
5	1.5	93

^aReaction condition: benzaldehyde (1 mmol), acetophenone (2 mmol), ammonium acetate (1.5 mmol), HNTf₂ catalyst at 80 °C for 50 min under solvent-free conditions.

^bIsolated yield.