How can I find all the endothermic reactions with a specific substrate? - (Mar/08/2019 )

How can I find all the endothermic reactions with a specific substrate?

You can't - we don't know that information as we don't know the full functions of every protein and process in the cell. This is assuming you are talking biological reactions. Even for chemical reactions you could only make assumptions about classes of compounds for a limited number of types of compounds.

Isn't there a database or something?

You could try pubchem, it aims to do this sort of thing.