75898-47-4Relevant articles and documents
A Simple Chiral Cu(II) Complex as an Effective Phase-Transfer Catalyst for the Enantioselective Alkylation of Dissymmetric Glycinate Ketimines
Bafqiren, Hanane,Zouihri, Hafid,Gmouh, Said,Jamal Eddine, Jamal
, p. 944 - 950 (2015/11/16)
Catalytic asymmetric benzylation of a dissymmetric tert-butylglycinate ketimine, incorporating 1-naphthyl and phenyl groups as the Schiff base substituents, under phase-transfer conditions was investigated. It was interesting to note that the sense of asymmetric induction of the alkylation of Z-imine stereoisomer is opposite to that of the corresponding E stereoisomer with a similar degree of enantioselectivity. More interestingly, the chiral Cu(II) complex of the Schiff base derived from (R)-2-phenylglycinol and 2-hydroxy-1-naphthaldehyde was found to catalyze the same reaction under solid-liquid conditions with comparable enantioselectivity (up to 60% ee) with respect to known cinchona alkaloid catalysts. The solvent/base-system parameter was shown to control the optimal catalytic activity. Chirality 27:944-950, 2015.
Chiral salen-metal complexes as novel catalysts for the asymmetric synthesis of α-amino acids under phase transfer catalysis conditions
Belokon, Yuri N,North, Michael,Churkina, Tatiana D,Ikonnikov, Nikolai S,Maleev, Victor I
, p. 2491 - 2498 (2007/10/03)
Chiral salen-metal complexes have been tested as catalysts for the C-alkylation of Schiff's bases of alanine and glycine esters with alkyl bromides under phase-transfer conditions (solid sodium hydroxide, toluene, ambient temperature, 1-10 mol% of the catalyst). The best catalyst, which was derived from a Cu(II) complex of (1R, 2R or 1S,2S)-[N,N′-bis(2′-hydroxybenzylidene)]-1,2-diaminocyclohexane, gave α-amino and α-methyl-α-amino acids with enantiomeric excesses of 70-96%.
