204762-24-3Relevant academic research and scientific papers
New carbohydrate bisphosphites as chiral ligands
Kadyrov, Renat,Heller, Detlef,Selke, Ruediger
, p. 329 - 340 (1998)
The synthesis of the 2,3-bisphosphite derivatives of phenyl 4,6-O-benzylidene-β-D-glucopyranoside leads to new chelating ligands. Their rhodium(I) and platinum(II) complexes have been tested as catalysts for the asymmetric hydroformylation of vinyl acetate, allyl acetate and p-methoxystyrene. Good regioselectivity (>90% branched product), but an enantioselectivity of only ≤36% ee were found under mild reaction conditions (25-40°C, 40-70 bar syngas).
Stereochemical features making deoxycholic acid derived tropos biphenylphosphites efficient chiral ligands for rhodium: The asymmetric hydrogenation of dimethylitaconate as a case study
Iuliano, Anna,Losi, Debora,Facchetti, Sarah
, p. 8472 - 8477 (2008/02/13)
(Chemical Equation Presented) Different deoxycholic acid derived biphenylphosphites, whose tropos nature was ascertained by NMR and CD measurements, were used in the rhodium-catalyzed asymmetric hydrogenation of dimethylitaconate achieving enantiomeric excesses up to 91%. The comparison of these results to those obtained using the corresponding atropoisomeric binaphthyl analogues, together with NMR and CD measurements on the rhodium complexes of some phosphites, allowed us to shed light on the nature of the active catalytic species and on the asymmetric induction process and hence to recognize the most appropriate stereochemical features to reach good levels of enantioselectivity.
