Monomeric copper(I) amido, alkoxide, and aryloxide complexes catalyze the addition of N−H and O−H bonds of amines and alcohols, respectively, to electron-deficient olefins. The ancillary ligands of the active catalysts include the N-heterocyclic carbene (NHC) ligands IPr, IMes, and SIPr {IPr = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene; IMes = 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene; SIPr = 1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene} as well as the chelating bisphosphine ligand dtbpe {dtbpe = 1,2-bis(di-tert-butylphosphino)ethane}. For the hydroamination and hydroalkoxylation of olefins, both aromatic and alkyl substituents can be incorporated into the nucleophile, and both primary and secondary amines are reactive. Monosubstituted and disubstituted olefins have been demonstrated to undergo reaction. For the addition of aniline to acrylonitrile, kinetic studies suggest a pathway that is dependent on the concentration of amine, olefin, and catalyst as well as inversely proportional to the concentration of the product 3-anilinopropionitrile. At low concentrations, the addition of tert-butylisonitrile increases the rate of catalysis. The proposed mechanism involves N−C or O−C bond formation by an intermolecular nucleophilic addition of the amido, alkoxide, or aryloxide ligand to free olefin.