boron and xantphos

A cooperative palladium/triorganoboron catalyst to accomplish the intramolecular aminocyanation of alkenes through the cleavage of N-CN bonds is reported. 4,5-Bis(diphenylphosphino)-9,9-dimethylxanthene (Xantphos) is found to be crucial as a ligand for palladium to effectively catalyze the transformation with high chemo- and regioselectivity. A range of substituted indolines and pyrrolidines with both tetra- or trisubstituted carbon and cyano functionalities are readily furnished by the newly developed cyanofunctionalization reaction. A preliminary example of enantioselective aminocyanation is also described.

Topics: Alkenes; Amination; Boron; Catalysis; Indoles; Nitriles; Palladium; Phosphines; Pyrrolidines; Stereoisomerism; Xanthenes

No longer a hindrance: copper-catalyzed electrophilic amination of aryl boronic esters is accomplished under mild reaction conditions using 2.5-5.0 mol % of a catalyst derived from copper tert-butoxide and Xantphos ligand. The reaction tolerates a wide range of functional groups and can be used to prepare some of the most hindered anilines made to date.

Topics: Amination; Aniline Compounds; Boron; Catalysis; Copper; Esters; Phosphines; Xanthenes