α-Alkylation of Nitriles Promoted by Hydrotalcite-Supported Catalysts

Significance

A ruthenium-grafted hydrotalcite (Ru/HT) and hydrotalcite-supported palladium nanoparticles (Pd_nano/HT) were readily prepared by treatment of hydrotalcite [HT; Mg₆Al₂(OH)₁₆CO₃] with aqueous RuCl₃·nH₂O and K₂PdCl₄, respectively. Ru/HT promoted the α-alkylation of benzylic cyanides with primary alcohols under Ar atmosphere to give the corresponding α-alkylated nitriles in 37-99% yield while the α-alky­lation of malononitrile and ethyl cyanoacetate did not occur. Pd_nano/HT promoted the α-alkylation of benzylic cyanides and ethyl cyanoacetate with benzylic aldehydes followed by hydrogenation to afford α-alkylated nitriles in 19-99% yield, whereas the reaction of acetophenone with malononitrile did not proceed.