Discloses herein is a catalytic process for producing organohalosilane monomers from a high-boiling residue resulting from the Direct Reaction of an organohalide with silicon. The high-boiling residue contains more conventionally cleavable compounds than conventionally uncleavable compounds. The process includes heating the residue in the presence of a catalyst comprising (1) one or more heterocyclic amines and/or one or more heterocyclic ammonium halides, and (2) one or more quaternary Group 15 onium compounds.