Heterogeneous Catalysts in Pictet-Spengler-Type Reactions

Table 1

The aforementioned solids’ specific area and acidity.

Entry	Solid	Surface area (m^2/g)	Acidity (mmol NH3/100 g)
1	B	50	21.6
2	Ca-B	48	21.1
3	H-B	82	30.9
4	AlPB	139	29.0
5	AlZrPV	208	36.7
6	MO	246	17.8