Abstract
The asymmetric hydrogenation of alpha-acetoxy acrylates to O-acetyl lactates with Rh catalysts based on chiral bisphospholane ligands was investigated in propylene carbonate (PC) as "green" solvent. In contrast to DuPHOS-type ligands, catASium M ligands lead to full conversion of the substrate in PC and induce excellent enantioselectivities for ethyl ester and methyl ester substrates (>98 %). Moreover, the undesired opening of the maleic anhydride moiety of the catASium M ligand observed in MeOH can be prevented under these conditions. The chiral product can be easily separated from the carbonate solvent by distillation. In this way, an ecologically benign process for the production of enantiopure lactic acid derivatives was established which offers a highly efficient catalytic transformation in a green solvent under mild conditions (1-10 bar H(2)).
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
