ISSN:
1434-193X
Keywords:
Nonlinear effects
;
Asymmetric catalysis
;
Ruthenium complexes
;
Atropisomeric phosphanes
;
Hydrogenation
;
Chemistry
;
General Chemistry
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
A strong positive nonlinear effect (asymmetric amplification) was found to take place during asymmetric hydrogenations using chiral atropisomeric diphosphane-ruthenium catalysts. As an example, at atmospheric pressure the use of 50% ee BINAP to prepare [(binap)Ru(Br)2] give rise to a hydrogenated product with 91% ee. The influence of temperature and hydrogen pressure on this effect are presented. These nonlinear effects can be explained on the basis of a hydrogenation mechanism in which diastereomeric dimers as pre-catalytic species are present.
Additional Material:
8 Ill.
Type of Medium:
Electronic Resource