''P''-Chiral phosphine

Two P-chiral "Kwon phosphines".[1]

P-Chiral phosphines are organophosphorus compounds of the formula PRR′R″, where R, R′, R″ = H, alkyl, aryl, etc. They are a subset of chiral phosphines, a broader class of compounds where the stereogenic center can reside at sites other than phosphorus. P-chirality exploits the high barrier for inversion of phosphines, which ensures that enantiomers of PRR'R" do not racemize readily. By contrast, most amines of the type NRR′R″ undergo rapid pyramidal inversion.

Research themes

Most chiral phosphines are C2-symmetric. Famous examples are DIPAMP and BINAP. They serve as chelating ligands supporting catalysts used in asymmetric hydrogenation and related reactions. DIPAMP is prepared by coupling the P-chiral methylphenylanisylphosphine.

P-Chiral phosphines are of particular interest in asymmetric catalysis because phosphorus or an attached metal center is the site of reactivity (enantioselectivity depends on the proximity of the chiral center to the prochiral substrate). P-Chiral phosphines have been investigated for two main applications, as ligands for asymmetric homogeneous catalysts and as nucleophiles in organocatalysis.[1]

References

  1. 1 2 Xiao, Y.; Sun, Z.; Guo, H.; Kwon, O. (2014). "Chiral Phosphines in Nucleophilic Organocatalysis". Beilstein Journal of Organic Chemistry. 10: 2089–2121. doi:10.3762/bjoc.10.218.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.