Regio- and Stereoselective Synthesis of Key 1-Methyl Carbapenem Intermediates via Hydroformylation Using a Zwitterionic Rhodium Catalyst was written by Park, H. S.;Alberico, E.;Alper, H.. And the article was included in Journal of the American Chemical Society in 1999.Safety of (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) This article mentions the following:
The asym. hydroformylation of a 4-vinyl β-lactam catalyzed by a rhodium catalyst with a chiral phosphine ligand was investigated. The catalytic system consisting of a zwitterionic rhodium catalyst, (NBD)Rh+(C6H5B–Ph3), and (S,S)-2,4 bis(diphenylphosphino)pentane, (S,S)-BDPP, gave branched aldehydes in high regio- and stereoselectivity. The hydroformylated products are key intermediates in the synthesis of 1-methylcarbapenem antibiotics. Using (3S,4R)-3-[(R)-1-(tert-butyldimethyl-silyloxy)ethyl]-4-vinyl-2-azetidinone as the reactant afforded aldehydes in a 97:3 branched-to-linear ratio and 91:9 to β- to α-branched isomers. The regio (branched/linear)- and stereoselectivity (β/α) was >99:1 when (3S,4R)-1-N-BOC-3-[(R)-1-methoxyethyl]-4-vinyl-2-azetidinone was used as the substrate. In the experiment, the researchers used many compounds, for example, (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2Safety of (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine)).
(2S,4S)-Pentane-2,4-diylbis(diphenylphosphine) (cas: 77876-39-2) belongs to chiral phosphine ligands. Although many reactions require more nucleophilic trialkylphosphines as catalysts, only a few chiral trialkylphosphines are available. Chiral ligands coordinate to metal centers to create an asymmetric environment around the reaction centers, which eventually affects enantioselectivity and reaction rate.Safety of (2S,4S)-Pentane-2,4-diylbis(diphenylphosphine)
Referemce:
Phosphine ligand,
Chiral phosphines in nucleophilic organocatalysis