• The Stetter reaction (conjugate addition of aryl aldehydes) catalyzed by CN-, is exemplified by the addition of pyridine-3-carboxaldehyde to acrylonitrile to give 4-oxo-4-(3-pyridyl)butyronitrile: Org. Synth. Coll., 6, 866 (1988). See also 3-Benzyl-5-(2-hydroxyethyl)-4-methylthiazolium chloride, L08750.
• The reaction is also applicable to acrylate esters and vinyl ketones; with acrylonitrile and phenoxyacetic acid, tetrahydrobenzopyran-4-carbonitrile is obtained in 41% yield.
• Free radical alkylation, acylation and arylation reactions also occur in the presence of t-butyl hydroperoxide and a Cu(II) catalyst: J. Chem. Soc., Chem. Commun., 1399 (1995). Several other free radical procedures have been reported involving intramolecular homolytic aromatic substitution to give carbocyclic and heterocyclic systems: Tetrahedron Lett., 36, 4307 (1995):