The reactions of phosphonates having a binaphthyloxy group with Grignard reagents gave the corresponding Pstereogenic phosphinates in good to high yields with high diastereoselectivity. In this reaction, an axis-to-center chirality transfer from a binaphthyl group to the resulting phosphorus atom took place stereospecifically. Both diastereomers with opposite configurations could be obtained by changing the combination of carbon-containing functional groups on the phosphorus atom and the Grignard reagents. Keywords: P-Stereogenic phosphonates | Binaphthyloxy phosphinate | Grignard reagentsIncreasing attention has been paid to the development of synthetic methods for P-stereogenic organophosphorus compounds with PC bonds 1 because of their wide applicability as optically active ligands and organocatalysts. For example, catalytic asymmetric desymmetrization of P-achiral substrates leads to P-stereogenic products.2 The addition of stoichiometric amounts of optically active compounds to P-achiral substrates can form diastereomers, and subsequent separation gives one of the diastereomers of P-stereogenic products.3 P-Chiral racemic substrates are also used to generate P-stereogenic products by procedures involving the separation of diastereomers 4 or catalytic selective functionalization of one of the enantiomers. 5 Additionally, the functionalization of optically active P-chiral substrates and of P-achiral substrates with a chiral auxiliary is being extensively developed. 6 In this context, we recently reported the transfer of the axial chirality of the binaphthyl group in phosphorothioic acid esters to the central P-chirality of monofluorinated thiophosphates via a reaction with a fluoride anion (Scheme 1a). 7In a series of studies on chalcogen isologues of phosphoric acid derivatives with a binaphthyl group, we synthesized a wide variety of phosphonates with a binaphthyl group. 8 We then envisioned that a conceptually new strategy for obtaining Pstereogenic organophosphorus compounds, i.e., axis-to-center chirality transfer, might play a role in the reaction of these phosphonates with a range of carbon nucleophiles (Scheme 1b). In fact, Drabowicz and co-workers used thienyllithium in the reaction of Scheme 1b, but the corresponding product was formed after 7 days in moderate yield with a diastereoselectivity of 63:37.9 Herein, we report a highly diastereoselective synthesis of P-stereogenic phosphinates by the reaction of phosphonates having a binaphthyloxy group with Grignard reagents.Initially, P-methylphosphonate 1a reacted with ethyl Grignard reagent 2b (1 equiv) in THF at 0°C for 30 min to give P-stereogenic phosphinate 3ab as a single diastereoisomer in 88% yield (Scheme 2a). In contrast to the reaction in Scheme 1a, only one of the PO bonds in 1a cleaved, and one molecule of Grignard reagent was introduced to the phosphorus atom. To our delight, the use of P-ethylated ester 1b and methyl Grignard reagent 2a led to phosphinate 3ba, which has a configuration opposite that of 3ab, in high yield (Scheme 2b...

Organophosphorus compounds with stereogenic phosphorus and carbon atoms have received increasing attention. In this regards, primary phosphines with a stereogenic carbon atom adjacent to the phosphorus atom were synthesized by the reduction in phosphonates and phosphonoselenoates with a binaphthyl group. Their oxidized products, i.e., phosphine oxides with a stereogenic tetrasubstituted carbon atom, were found to undergo BEt3-mediated radical addition to cyclohexene to give P-stereogenic secondary phosphine oxides with a diastereoselectivity of 91:9. The products were characterized by ordinary analytical methods, such as Fourier transform infrared spectroscopy; 1H, 13C, and 31P NMR spectroscopies; and mass spectroscopy. Computational studies on the phosphorus-centered radical species and the obtained product implied that the thermodynamically stable radical and the adduct may be formed as a major diastereomer. The radical addition to a range of alkenes took place in an anti-Markovnikov fashion to give P-stereogenic secondary phosphine oxides. A variety of functional groups in the alkenes were tolerated under the reaction conditions to afford secondary phosphine oxides in moderate yields. Primary phosphines with an alkenyl group, which were generated in situ, underwent intramolecular cyclization to give five- and six-membered cyclic phosphines in high yields after protection by BH3.