Tertiary amines useful as catalysts for preparing polyurethane foams are provided. Tertiary amines are employed to catalyze the trimerization reaction of isocyanates and the reaction between isocyanates and active hydrogen-containing compounds, such as a polyol and/or a blowing agent. Such tertiary amine has the general formula ##STR00001## wherein R.sup.1, R.sup.2, Y, Z, and n are defined herein.