Composite nanofibers of polyurethane and catalytically active Pd- or Cu-functionalized poly(amido amine) dendrimers were electrospun and subsequently coated with poly(p-xylylene) by the chemical vapor deposition. After removal of the inner polyurethane template matrix, the dendrimers remained encapsulated inside the confinement and the leaching behavior of the caged dendritic catalysts was studied. The tube system was successfully used as a readily reusable tea bag type catalyst for Suzuki Miyaura couplings and alkyne/azide click reactions.