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
Enantioselective cyanosilylation of aldehydes catalyzed by a multistereogenic salen–Mn(<scp>iii</scp>) complex with a rotatable benzylic group as a helping hand
A multistereogenic salen–Mn(iii) complex bearing an aromatic pocket and two benzylic groups as helping hands was found to be efficient in the catalysis of asymmetric cyanosilylation.
Parallel synthesis of modular chiral Schiff base ligands and evaluation in the titatium(IV) catalyzed asymmetric trimethylsilylcyanation of aldehydes
作者:Belén Rodríguez、Mireia Pastó、Ciril Jimeno、Miquel A. Pericàs
DOI:10.1016/j.tetasy.2005.11.022
日期:2006.1
Highly modular tridentate Schiff base ligands arising from enantiopure epoxyalcohols have been prepared and evaluated in catalysis using parallel methods. The key structural motifs and experimental parameters have been identified, allowing enantioselectivities of up to 77% ee in the titatium-catalyzed trimetbylsilyl cyanide addition to aldehydes. (c) 2005 Elsevier Ltd. All rights reserved.