A range of asymmetric transformations are catalyzed by transition‐metal complexes of the title ligands with excellent enantioselectivities. The ligands, which were applied successively in Rh‐catalyzed hydrogenation and Rh‐ or Pd‐catalyzed CC bond‐forming reactions, were synthesized by nucleophilic substitution of (R)‐(bromo(tert‐butyl)methylphosphanyl)borane (see scheme).

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Optically active dinuclear palladium complexes containing a Pd-Pd bond were prepared by using (R,R)-bis(tert-butylmethylphosphino)methane ((R,R)-t-Bu-MiniPHOS). The dinuclear palladium complexes coupled with silver triflate exhibited good to excellent enantioselectivities up to 99% in palladium-catalyzed alkylative ring-opening reactions of azabenzonorbornadienes.

General.All solvents used in reactions were dried and purified according to standard procedure. NMR spectra were measured with JEOL JMN-GXS-500 (500 MHz) or JEOR JMN-LA-400 (400 MHz) spectrometer in CDCl 3 . Chemical shifts were reported in δ ppm. Optical rotationswere measured with JASCO DIP-370 polarimeter. Enantiomeric excesses were determined by HPLC analysis using Chiralcel AD, OJ-H, OD-H, OB, IA columns and varying concentrations of 2-propanol/hexane as the mobile phase. X-ray crystal structure data were collected using a Bruker SMART APEX II diffractmeter with Mo-Kα radiation. Silica gel (Kanto Chemical, Silica Gel 60N for flash chromatography) was used for column chromatography. (S)-tert-Butylmethyl(phenylethynyl)phosphine-borane (3a)To a solution of (S)-tert-butylmethylphosphine-borane (1) (>99% ee, 1.8 g, 15.4 mmol) in dry Et 2 O (60 mL) was added nBuLi (11.6 mL of a 1.60 M solution in hexane, 18.5 mmol) at -78 °C under nitrogen, and the mixture was stirred for 15 min. 1,2-Dibromoethane (2.0 mL, 23.1 mmol) was added dropwise, and the reaction mixture was stirred at -78 °C. After 2 h, lithium phenylacetylide (30.8 mmol, 30 mL of Et 2 O solution) was added to the reaction mixture, and the mixture was stirred at room temperature. After 1.5 h, the reaction was quenched with 1 M HCl. The mixture was extracted with EtOAc three times. The combined organic layers were washed with saturated NaHCO 3 and brine, and dried over Na 2 SO 4 . After filtration, the filtrate was concentrated under reduced pressure, and the residue was purified by chromatography on silica gel (hexane/EtOAc = 5/1) to give (S)-tert-butylmethyl(phenylethynyl)phosphine-borane (3a) (97% ee, 2.8 g, 12.8 mmol, 83%) as white solid.

Amines Q 0810Optically Active Dinuclear Palladium Complexes Containing a Pd-Pd Bond: Preparation and Enantioinduction Ability in Asymmetric Ring-Opening Reactions. -The reaction of azabenzonorbornadienes with dimethylzinc in the presence of the new dinuclear palladium complex proceeds with good to excellent enantioselectivities compared to the common mononuclear species. -(OGURA, T.; YOSHIDA, K.; YANAGISAWA, A.; IMAMOTO*, T.; Org.