6592-00-3Relevant academic research and scientific papers
Asymmetric hydrogenation of α-keto acid derivatives by rhodium-{amidophosphine-phosphinite} catalysts
Carpentier, Jean-Francois,Mortreux, Andre
, p. 1083 - 1099 (2007/10/03)
The enantioselective hydrogenation of several α-keto esters (3a-f, 5a-j), α-keto amides (7a-e) and isatine derivatives (9a-d) with a set of four representative neutral homogeneous rhodium-amidophosphine-phosphinite catalysts has been investigated. Trifluoroacetate-Rh-AMPP catalytic precursors promoted the rapid, efficient synthesis of aliphatic α-hydroxy esters 4a-f in moderate to high enantioselectivities (66-95% eel, in contrast to most aromatic α-hydroxy esters 6a-j (8-81% eel. Best enantioselectivities for α-hydroxy amides 8a-e (85-95% eel and dioxindoIes 10a-d (80-94% eel were obtained with chloro-Rh-AMPP precursors. It is proposed that, contrary to α-keto amides, α-keto esters do not chelate onto the rhodium center and that, in such circumstances, the asymmetric induction is mainly controlled by the steric hindrance around the C=O function.
ASYMMETRIC HYDROGENATION OF ACTIVATED KETO COMPOUNDS CATALYZED BY NEW CHIRAL PERALKYL-AMPP RHODIUM COMPLEXES
Hatat, Corinne,Karim, Abdallah,Kokel, Nicolas,Mortreux, Andre,Petit, Francis
, p. 3675 - 3678 (2007/10/02)
Readily available peralkyl aminophosphinephosphinite ligands (alkyl-AMPP) give neutral rhodium complexes active for the catalytic reduction of some activated ketones under atmospheric hydrogen pressure at ambient temperature (ee=80percent).
