This work presents a comparative study between alternative catalytic systems, metal-beta-diketones complexes (iron, copper, chromium, and tin), and the commercial catalyst dibutyltin dilaurate, DBTDL, in the polyurethanes synthesis obtained from isophorone diisocyanate (IPDI) and polyols; as polypropyleneglycol/diethyleneglycol and 1,6-hexanodiol polyadipate (polyester A-Mn = 2000 g/mol and polyester B-Mn = 1000 g/mol) reactions. The polyurethanes synthesis was followed by the IPDI consumption in time, verified by infrared spectroscopy (FTIR) through the decrease of free NCO characteristic band at 2300-2200 cm(-1). The FTIR data was used to determine the polyurethanes formation kinetic behavior. It was verified that for the reactions with polyethers excess, DBTDL catalyst was more effective when compared to metal-beta-diketones complexes, while for the reactions with polyester, A and B, the metal-beta-diketones complexes were more effective. (C) 2009 Wiley Periodicals, Inc. J Appl Polym Sci 115:1797-1802, 2010