The catalytic properties of a chemically stable iron porphyrin MOF were evaluated in a reaction with ethyl diazoacetate. In contrast to its homogeneous counterpart, an Fe-porphyrin-MOF features a different reaction pathway leading to the formation of pyrazoline due to the confinement of catalytic sites within the MOF network. Unexpectedly, a sharp increase of the selectivity from 35% (run 1) to 86% (run 5) occurs upon catalyst recycling.