This work has demonstrated in situ mid-infrared (mid-IR) monitoring with the ReactIR/DiComp probe to be a powerful technique for real-time analysis of catalytic three-phase processes. The usefulness of FTIR/ATR spectroscopy to resolve dilemmas about reaction mechanisms and providing reliable kinetic data by means of chemometric analysis of a series of mid-IR spectra taken during the reaction course was successfully shown on an example of Pd/C catalyzed enantioselective hydrogenation of prochiral, exocyclic alpha,beta-unsaturated ketones, using (S)-proline as a chiral auxiliary in various solvents. The intermediate formed by the chemical interaction between an alpha,beta-unsaturated ketone and (S)-proline, which was supposed previously to confirm the proposed asymmetric synthesis approach, was not evidenced by the performed investigation to the detection limit of 0.2 mmol/l. (C) 2003 Elsevier B.V. All rights reserved.