An organocatalytic method for a preparation of polyhedral silsesquioxanes characterized by use of N-heterocyclic carbenes, NHC, as organocatalysts, is described in present invention. Stable, isolable NHCs or their precursors that are called also cryptocarbenes could be used in disclosed process. Polyhedral silsesquioxanes could be prepared from hydrolyzates of functional trialkoxysilanes, silsesquioxane resins or from other already existing polyhedral silsesquioxanes compounds by mixing them with an organocatalytic NHC in an organic solvent at an appropriate temperature. Because of excellent solubility of carbenes in a reaction media high yields of polyhedral silsesquioxanes are obtained even at a concentration of NHC lower than 1 mol %.
F.33 Slovenian patent