Syntheses and Coordination Chemistry of Chiral Phosphanyl Glycerols and Their Derivatives – X-ray Structure of (R)-Ph2P–CH2–CaH–O–B(Ph)–O–CbH2(Ca–Cb)

Abstract

Reaction of (R)-(+)-2,3-epoxy-1-propanol with Ph2PH, Ph(Me)PH, or PhPH2 in the superbasic medium KOH/DMSO affords the novel chiral phosphanes 1a–1c. While 1a is obtained enantiomerically pure, 1b and the secondary phosphane 1c are formed as mixtures of diastereoisomers (RPRC, SPRC) with homochiral β carbon atoms. Derivatization of 1a with phenylboronic acid or 2,2-dimethoxypropane yields 2a and 3a with 1,3,2-dioxaborolane and 1,3-dioxolane ring systems, respectively. The X-ray structure of 2a (space group P21) reveals the presence of four molecules of R configuration in the unit cell. Nucleophilic phosphanylation of (R)-(–)-2,3-O-isopropylideneglycerol tosylate with Ph2PH, Ph(Me)PH, or PhPH2 yields chiral 3a–3d. Compound 3b was obtained enantiomerically pure. The secondary phosphane 3c has been employed in syntheses of the hydrophilic tertiary phosphanes 3e, 3f and of the novel bidentate phosphane ligands 3g, 3h, all of which have homochiral β carbon atoms. PdII complexes PdL2Cl2 of 1a, 2a, 3a (L) are formed as mixtures of cis/trans isomers. RhI complexes of 1a, 3a, and bidentate 3h have also been synthesized.