1044281-62-0Relevant academic research and scientific papers
Chiral oxo- and oxy-functionalized diphosphane ligands derived from camphor for rhodium(I)-catalyzed enantioselective hydrogenation
Komarov, Igor V.,Monsees, Axel,Spannenberg, Anke,Baumann, Wolfgang,Schmidt, Ute,Fischer, Christine,Boerner, Armin
, p. 138 - 150 (2003)
The synthesis of two series of diastereomeric oxo- and oxysubstituted diphosphanes 7a-9a and 7b-9b, as well as an analogous nonfunctionalized diphosphane 17, was performed starting from (R)-camphor. The new diphosphanes were used as ligands in the enantioselective rhodium(I)-catalyzed hydrogenation of functionalized olefins - α- and β-de hydroamino acids and their esters - in order to elucidate the effect of the oxo- and oxy-functional groups. The enantioselectivities, ranging from 2-90% ee, and the rates were strongly dependent on the type and relative position of the oxo or oxy substituent in the catalyst. Possible explanations for the effects are given. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2003.
