Synthesis, Characterization, and Study of Catalytic Activity of Chiral Cu(II) and Ni(II) Salen Complexes in the α-Amino Acid C-α Alkylation Reaction(46 views) Tovmasyan AS, Mkrtchyan AF, Khachatryan HN, Hayrapetyan MV, Hakobyan RM, Poghosyan AS, Tsaturyan AH, Minasyan EV, Maleev VI, Larionov VA, Ayvazyan AG, Shibata N, Roviello GN, Saghyan AS
by Anna S. Tovmasyan 1,Anna F. Mkrtchyan 1,2,*,Hamlet N. Khachatryan 2,Mary V. Hayrapetyan 2,Robert M. Hakobyan 3,Artavazd S. Poghosyan 1,Avetis H. Tsaturyan 1,2,Ela V. Minasyan 1,2,Victor I. Maleev 4,Vladimir A. Larionov 4,5,Armen G. Ayvazyan 3,Norio Shibata 6,Giovanni N. Roviello 7,* andAshot S. Saghyan 1,2,**Authors to whom correspondence should be addressed.
References: Not available.
Synthesis, Characterization, and Study of Catalytic Activity of Chiral Cu(II) and Ni(II) Salen Complexes in the α-Amino Acid C-α Alkylation Reaction
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 Сα-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.
Synthesis, Characterization, and Study of Catalytic Activity of Chiral Cu(II) and Ni(II) Salen Complexes in the α-Amino Acid C-α Alkylation Reaction
Kállay C, Dávid A, Timári S, Nagy EM, Sanna D, Garribba E, Micera G, De Bona P, Pappalardo G, Rizzarelli E, Sóvágó I * Copper(II) complexes of rat amylin fragments(480 views) Dalton T (ISSN: 1477-9234, 1477-9226, 1477-9234electronic), 2011 Oct 14; 40(38): 9711-9721. Impact Factor:3.838 ViewExport to BibTeXExport to EndNote