A new family of Cu(II) and Ni(II) salen complexes was synthesized and fully characterized through various physicochemical methods. Their catalytic activity was evaluated in the phase transfer C_α-alkylation reaction of the Schiff bases of D,L-alanine ester and benzaldehyde derivatives. It was found that the introduction of a chlorine atom into the ortho- and para-positions of the phenyl ring of the substrate resulted in an increase in both the chemical yield and the asymmetric induction (ee 66–98%). The highest enantiomeric excess was achieved in the case of a Cu(II) salen complex based on (S,S)-cyclohexanediamine and salicylaldehyde at −20 °C. The occurrence of a bulky substituent in the ligand present in the complexes led to a drastic decrease in ee and chemical yield. For instance, the introduction of bulky substituents at positions 3 and 5 of the phenyl ring of the catalyst resulted in a complete loss of the stereoselectivity control in the alkylation reaction.

A method of synthesis of 1,1′-(alkanediyl)bis{3-cyano-4-[4,5,5-trimethyl-2-oxo-5 H-furan-3-yl]-pyridin-2(1 H)-ones} from the corresponding lactones is developed. The synthesized compounds undergo...

A series of 4-(thiophen-2-yl)-substituted nicotinonitriles were prepared by a three step procedure including condensation and cyclization of 2-acetylthiophene. A more efficient synthesis of the target products is proposed and the transformation of some of the synthesized nicotinonitrles into 1H-pyrazolo[3,4-b]pyridines is described.