Derivatives of 1,1-dimethyl-1-(2-hydroxypropyl)amine benzoylformimide (BFI and 1a-c) were synthesized from 1,1-dimethylhydrazine, propylene oxide, and p-substituted benzoylformic acid ester, respectively, and their activity as thermal/photolatent bases and photoradical initiators was studied in detail. Their thermal decomposition activity increased by the electron-donating substituents on the benzene ring, being in order of 1a (p-NMe2) > 1b (p-MeO) > BFI (H) > 1c (p-NO2). Photolysis activities were also affected by the substituents, in the following order: 1b > BFI > 1a > 1c. Thermal and photoinduced base-catalyzed polymerization of the epoxide/thiol system and photoradical polymerization of a vinyl monomer, 2-hydroxylethyl methacrylate, were carried out by using the aminimides as latent initiators. Their activity as thermal base and photobase/radical initiators could be correlated to their thermal decomposition and the photolysis activity, respectively. (c) 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 4292-4300