Abstract: Process for the recovery of reactants and products from a catalyst containing residue, e.g., a residue obtained from the hydrocyanation of olefins such as butadiene using a zero-valent nickel complex as the hydrocyanation catalyst wherein the complex is promoted with a triarylborane or a zinc compound such as zinc chloride. The residue is mixed, i.e., extracted with a solvent consisting essentially of monoolefinically unsaturated nitriles, e.g., 3-pentenenitrile. The resulting extract containing the pentenenitriles and the desired products, e.g., adiponitrile and its precursors is separated from the insoluble materials consisting essentially of catalyst residue and at least a portion thereof is returned to the hydrocyanation process.