Non-C2-symmetrical antimony–phosphorus ligand, (R/S)-2-diphenylphosphano-2′-di(p-tolyl)stibano-1,1′-binaphthyl (BINAPSb): preparation and its use for asymmetric reactions as a chiral auxiliary

Synthesis of Optically Active P-Chirogenic Ferrocene-Fused Benzophosphole by Diastereoselective Intramolecular Cyclization of Phosphanylferrocene Derivatives

“…for a chiral auxiliary in asymmetric reaction, we finally examined the Pd-catalyzed hydrosilylation of styrene by the use of (S Fc ,R P )-(3), because enantiomerically pure monodentate phosphine ligands based on ferrocenyl scaffolds have proved to be so successful in the asymmetric hydrosilylation of olefines 15,16. The reaction of styrene with trichlorosilane in the presence of [PdCl(C 3 H 5 )] 2 (0.1 mol%) and (S Fc ,R P )-(3) (0.4 mol%) at 0 °C to rt resulted in the enantioselective hydrosilylation to afford (R)-1-phenylethanol (49 %ee) in 39% yield.…”

Microwave-Assisted Debromination of α-Bromoketones with Triarylstibanes in Water

“…Therefore, we were interested in reactivity of group 15 (pnictogen) reagents and the reaction of 1a using various triarylpnictogen reagents such as Ph 3 P 3d, Ph 3 As 3e, and Ph 3 Bi 3f was also examined under microwave irradiation in water. The debromination product 4a was obtained in good yield (83%) using Ph 3 P as the reagent while the yields were 3 and 20% using Ph 3 As and Ph 3 Bi, respectively (entries [18][19][20]. These results including the case of Ph 3 Sb do not follow the periodic table trend of reactivity.…”

“…[1][2][3] In particular, trivalent organoantimony(III) compounds (stibanes) have been used for a wide variety of transformations such as alkylation of carbonyl compounds, 4) Pd-catalyzed cross-coupling reactions, [5][6][7][8][9][10][11] photochemical reaction, 12) catalytic oxidative cyclization, 13) and asymmetric reactions with optically active compounds. [14][15][16][17][18] Stibane reagents such as triphenylstibane have low toxicity, [19][20][21] and are therefore promising reagents in organic synthesis. Extensive studies have been carried out on the reductive dehalogenation reactions of α-halocarbonyl compounds using reagents such as active metals, low-valent metals, metal hydrides, and halide salts.…”

Alkene Reduction: Hydrosilylation

“…The use of other BINAP derivatives as ligands in hydrosilylation has provided mixed results. Replacement of one of the phosphorus groups with antimony, ligand (23a) , gave ( R ) -(3) in 78% yield and 95% ee (Scheme 4.6 ) [21] . Replacement of both phosphorus atoms, (23b) , resulted in only 10% yield and 12% ee.…”