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Non‐Linear Effects in Ruthenium‐Catalysed Asymmetric Hydrogenation with Atropisomeric Diphosphanes
Author(s) -
Girard Christian,
Genêt JeanPierre,
Bulliard Michel
Publication year - 1999
Publication title -
european journal of organic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 1434-193X
DOI - 10.1002/(sici)1099-0690(199911)1999:11<2937::aid-ejoc2937>3.0.co;2-b
Subject(s) - ruthenium , chemistry , binap , diastereomer , asymmetric hydrogenation , enantioselective synthesis , catalysis , hydrogen , atmospheric pressure , medicinal chemistry , organic chemistry , oceanography , geology
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.