Enantioselective cyanosilylation of aldehydes catalyzed by novel camphor derived Schiff bases-titanium(IV) complexes
作者:Ewelina Błocka、Mariusz J. Bosiak、Mirosław Wełniak、Agnieszka Ludwiczak、Andrzej Wojtczak
DOI:10.1016/j.tetasy.2014.03.001
日期:2014.4
Five tridentate Schiff bases have been prepared from (1R,2S,3R,4S)-3-amino-1,7,7-trimethylbicyclo[2.2.1]heptan-2-ol and salicylaldehydes. X-ray structure investigation revealed differences in their molecular conformation, and their titanium(IV) complexes have been studied with NMR techniques. Among them the complex with the Schiffbase obtained from 2-hydroxy-3-isopropylbenzaldehyde, is the most selective
Synthesis, characterization and catalytic property of chiral oxo-vanadium (+)-pseudoephedrine complex supported on magnetic nanoparticles Fe3O4 in the cyanosilylation of carbonyl compounds
作者:Amin Rostami、Bahareh Atashkar
DOI:10.1016/j.catcom.2014.08.029
日期:2015.1
Vanadium complex of pseudoephedrine immobilized on magnetic nanoparticle Fe3O4(Pseudoephedrine) @MNPs] was prepared and characterized by UV-vis, SEM, XRD, TGA, EDX, FT-IR, AGFM and elemental analysis techniques. VO(Pseudoephedrine)@MNPs was found to catalyze the cyanosilylation of carbonyl compounds using TMSCN in good yields with 8-25% enantiomeric excesses under solvent-free conditions at room temperature. The catalyst was recycled up to 15 times with little loss of activity and enantioselectivity. (C) 2014 Elsevier B.V. All rights reserved.