1.
J Org Chem
; 85(22): 14516-14526, 2020 11 20.
Article
in English
| MEDLINE
| ID: mdl-32627554
ABSTRACT
Kinetic separation of the commercially available cis/trans-(+)-limonene oxide mixture by ring opening with primary phosphido nucleophiles LiPHR (R = ferrocenyl, Ph, Cy, t-Bu, Mes* (Mes* = 2,4,6-(t-Bu)3C6H2)), followed by treatment with aqueous NH4Cl and H2O2, gave unreacted cis-(+)-limonene oxide and diastereoenriched mixtures of the secondary phosphine oxides (SPOs) PHR(trans-(+)-Lim-OH)(O), which could be separated by chromatography and/or recrystallization. This one-pot synthesis uses a cheap chiral material and commercially available primary phosphines to control the configuration of the new P-stereogenic SPOs, which are potentially useful as ligands for metal complexes in asymmetric catalysis.