| Treatment of Cl2P(O)CH2Ph with S(-)-1,1 '-binaphthyl-2,2'-diol, S(-)BINOL, in the presence of two equivalents of triethylamine, afforded (S(-)BINOL)P(O)CH 2Ph in high yield. Treatment of (S(-)BINOL)P(O)CH 2Ph with butyllithium and alkyl halides (RX = Mel, EtI, allylBr, PhCH 2Br) was found to proceed with good yields (up to 94%) and good diastereoselectivities (up to 91:9). This demonstrates that BINOL is a good chiral auxiliary for the alkylation of lithium-stabilized phosphonates. Upon purification by column chromatography, the chiral auxiliary from (S(-)BINOL)P(O)CHMePh- S was cleaved under basic conditions and enantiopure (HO)2P(O)CHMePh- S was isolated.; Treatment of vanadium starting materials with chiral and achiral phosphonic acids and phosphonates provided the soluble [BuPPh3]4[(V 2O2(OH)2)6(O3PR)8] R = CH(CH2Ph)Pr and CH(Et)Pr, [(VO)6(O3PR) 8{lcub}Cl{rcub}] R = CH2Ph, CHMePh-S, and [(V 14O22)(OH)4(O3PR)8] 6- with R = CHEtPr, CH(CH2Ph)Pr, and CH(Me)Ph- S cage complexes. These are the first reported examples of vanadium phosphonate cage molecules synthesized with racemic and enantiopure phosphonate starting materials. In addition, treatment of V2O 5 with (HO)2P(O)R in ethanol, where R = Ph and CHMePh- S, afforded (VO)(O3PR)·yEtOH·xH2O. (VO)(O3PCHMePh-S)·H2O is the first layered vanadium phosphonate material synthesized using an enantiopure phosphonic acid. These materials were tested for catalytic activity in the asymmetric epoxidation of geraniol and cinnamyl alcohol. |
