A mobile microreactor system, with flow and temperature control for organic synthesis, is described. The system can be used anywhere a venting outlet is available. The microreactors can be operated in different flow patterns (continuous flow, stop-flow, or programmed-flow) providing reaction times from a few minutes to a few hours. The system was tested for the catalytic oxidation of benzyl alcohol to benzaldehyde by tetrapropylammonium perruthenate (TPAP) with N-methyl-morpholine-N-oxide in the liquid phase under stop-flow mode and on supported TPAP with oxygen under continuous flow mode. The conversion of benzyl alcohol in the microreactor was close to that of a small batch reactor for the liquid phase reaction. For the multiphase reaction, a conversion of 30-40% was obtained with residence times below 1 min.