Asymmetric allylic substitutions on symmetrical and non-symmetrical substrates using [5]ferrocenophane ligands
作者:Radovan Šebesta、Andrea Škvorcová、Branislav Horváth
DOI:10.1016/j.tetasy.2010.05.054
日期:2010.8
A series of [5]ferrocenophane diphosphane ligands were used in Pd-catalyzed allylic substitution reactions. With a symmetrical substrate, 1,3-diphenylpropenyl acetate, enantioselectivities between 70% and 94% ee were observed. Several non-symmetrically substituted allylic substrates were also used. Depending on the substituents of the non-symmetrical allylic substrates, various degrees of regioselectivity (from 1:1 to 100:0) and enantioselectivity (from 0% to 96% ee) were observed. Tentative catalytically active complexes were studied by DFT computational methods. (C) 2010 Elsevier Ltd. All rights reserved.
Influence of structural changes in ferrocene phosphane aminophosphane ligands on their catalytic activity
作者:Radovan Šebesta、Andrea Škvorcová
DOI:10.1016/j.jorganchem.2009.01.027
日期:2009.5
New phosphane aminophosphane ligands based on [3]ferrocenophane skeleton were synthesized using a direct double lithiation followed by phosphanylation. Influence of ligand structure on catalytic performance was evaluated by performing a series of Pd-catalyzed allylic substitution on different substrates. Enantioselectivities up to 55% ee were obtained with bridged ligand compared to 33% ee with analogous non-bridged BoPhoz ligand. (C) 2009 Elsevier B.V. All rights reserved.