1 Centre for Research in Molecular Modeling and Department of Chemistry and Biochemistry, Concordia University, 7141 Sherbrooke Street West, Montreal, Quebec H4B 1R6, Canada.

A comparative study of the concerted hydrolysis of H-, CF3-, CH3-, and Ph-substituted N-sulfinylamines (R-NSO) and isocyanates (R-NCO) was performed using B3LYP/6-31+G(2d,2p). The "two-water-molecule" model was found to be sufficient for a proper description of the hydrolysis reaction for both classes of compounds. Despite their overall similar reactivity, N-sulfinylamines react across both the N=S and the S=O bonds, whereas isocyanates hydrolyze predominantly through the N=C bond, in agreement...