Catalysis of Organic..

Pugin et al. 301temperature, then transferred by syringe into an Argon filled NMR tube. The NMRspectra were recorded on a Bruker DPX spectrometer operating at 300.13 MHzproton resonance.Synthesis of 2Dicyclohexylphosphine (0.34 ml, 1.7 mmol) was added to 1,1’-bis(diphenylphospino)-2,2’-bis(α-dimethylaminoethyl)ferrocene (536 mg,0.77 mmol) in 5 ml of acetic acid and the red solution is stirred overnight at 105°C.After cooling, the reaction mixture was partitioned between toluene and water. Theaqueous phase was saturated with sodium chloride and extracted with toluene. Theorganic phase was dried over anhydrous Na 2 SO 4 , evaporated in vacuo, andchromatographed on silica gel (Merck Si60, heptane/TBME 50:1 eluent) to provide424 mg (55%) of 2 as a yellow crystalline solid. 1 H-NMR (C 6 D 6 ): δ 0.8-2.0 (m,50H), 3.11 (s, 2H), 3.56 (m, 2H), 4.40-4.55 (m, 4H), 6.85-7.55 (m, 20H). 31 P-NMR(C 6 D 6 ): δ +16.3 (d); -25.5 (d).Synthesis of 4s-BuLi (30.45 ml of 1.3 molar in cyclohexane, 39.6 mmol) was added dropwise over30 minutes to a stirred solution of (S,S)-1,1’-bis[1-(dimethylamino)ethyl]ferrocene 10(5.144 g, 39.6 mmol) in 25 ml of diethyl ether cooled in an ice-water bath. Afterstirring with cooling for 3.5 hours, (MOD) 2 PCl (14.44 g, 42.9 mmol) was added, thecooling bath was removed, and the reaction mixture was stirred overnight. Themixture was quenched with with water and extracted with TBME. The organicphase was dried over anhydrous Na 2 SO 4 , evaporated in vacuo, and purified bychromatography on silica gel (Merck Si60, ethanol). Recrystallization from ethanolprovided 7.03 g (46%) of a yellow, crystalline solid 11 which was used in the nextreaction.Di-t-butylphosphine (18.9 g of 10% solution in acetic acid, 12.02 mmol) wasadded to a solution of the product (4.0 g, 4.31 mmol) from the previous step in 20 mlof acetic acid and this reaction mixture was stirred overnight at 105°C. After cooling,the mixture is partitioned between dichloromethane and water. The organic phasewas dried over anhydrous Na 2 SO 4 , evaporated in vacuo, and purified bychromatography on silica gel (Merck Si60, 10/1/0.1 heptane/TBME/triethylamine) toprovide 4 as orange, crystals compound (yield: 50%). 1 H-NMR (C 6 D 6 ): δ 7.73 (s,2H), 7.70 (s, 2H), 7.23 (s, 2H), 7.21 (s, 2H), 4.18 (m, 2H), 3.93 (m, 2H), 3.70 (q,2H), 3.65 (m, 2H), 3.36 (s, 6H), 3.26 (s, 6H), 2.33 (m, 6H), 2.24 (s, 12H), 2.12 (s,12H), 1.42 (d, 18H), 1.15 (d, 18H). 31 P-NMR (C 6 D 6 ): δ +52.2 (d), -26.5 (d).Synthesis of 640% Aqueous methylamine (64 ml, 33.2 mmol) was added to 1,1’-bis(diphenylphospino)-2,2’-bis(α-acetoxyethyl)ferrocene 12 (403 mg, 0.55 mmol) inisopropanol (5 ml) and the reaction mixture was stirred in a closed pressure ampouleat 90°C for 66 hours. After evaporation in vacuo, the residue was dissolved in ethylacetate/heptane 1:1 and extracted with 10% aqueous citric acid. The aqueous phasewas washed with ethyl acetate/heptane 1:1, basified with 2N NaOH basic and