Catalysis of Organic..

302Chiral Ferrocene Ligandsextracted with dichlromethane. The organic phase was dried over anhydrous Na 2 SO 4 ,evaporated in vacuo, and purified by chromatography on silica gel (Merck Si60, 1%cyclohexane in ethonal) to provide a yellow solid 13 (58%) of that was used in thenext reaction.A solution of the product from the previous step (209 mg, 0.313 mmol),triethylamine (0.2 mL, 1.4 mmol), and diphenylphosphine chloride (0.15 ml,0.81 mmol) in toluene (2 mL) was stirred at 50 °C overnight. After cooling, heptane(10 mL) was added, the suspension was filtered, the filtrate was evaporated in vacuo,and chromatographed on silica gel (Merck Si60 80/20/2.5 heptaneethyl acetate/triethylamine)to provide 6 as solid orange foam (yield: 96%). 1 H-NMR (C 6 D 6 ), δ7.5 –6.8 (m, 40H), 5.24 – 5.12 (m, 2H), 4.52 (m, 2H), 4.25 (m, 2H), 3.01 (m, 2H), 2.19 (d,6H), 1.60 (d, 6H). 31 P-NMR (C 6 D 6 ): δ +59.1 (d); -24.6 (d).References1. H.U. Blaser, F. Spindler, and M. Studer, Applied Catalysis A: General 221119 (2001). H.U. Blaser, E. Schmidt eds., “Large Scale AsymmetricCatalysis,” Wiley-VCH, Weinheim, 2003.2. Chim. Oggi / Chem. Today 22(5) (2004), Supplement on Chiral Catalysis3. H.U. Blaser, Ch. Malan, B. Pugin, F. Spindler, H. Steiner, and M. Studer,Adv. Synth. Catal. 345, 103 (2003). W. Tang and X. Zhang, Chem. Rev.103, 3029 (2003).4. H.U. Blaser, M. Lotz, F. Spindler, "Asymmetric Catalytic HydrogenationReactions with Ferrocene Based Diphosphine Ligands" in Handbook ofChiral Chemicals, 2nd Edition, D. J. Ager (Ed.), CRC Press, Boca Raton20055. H. U. Blaser, W. Brieden, B. Pugin, F. Spindler, M. Studer, and A. Togni,Topics in Catalysis 19, 3 (2002)6. J. J. Almena Perea, A. Borner, P. Knochel, Tetrahedron Lett. 39, 8073(1998); J. J. Almena Perea, M. Lotz, P. Knochel, Tetrahedron: Asymmetry10, 375 (1999); M. Lotz, et al., ibid. 10, 1839 (1999).7. A. Togni, et al., J. Am Chem Soc. 116, 4062 (1994).8. N. W. Boaz, et al., Org. Lett. 4, 2421 (2002).9. W. Weissensteiner, et al. Organometallics 21, 1766 (2002).10. L. Schwink, P. Knochel, Chem. Eur. J. 4, 950 (1998).11. 1 H-NMR (C 6 D 6 ): δ 7.52 (s, 2H), 7.50 (s, 2H), 7.14 (s, 2H), 7.11 (s, 2H),4.37-4.28 (m, 6H), 3.86 (m, 2H), 3.30 (two s, 12H), 2.1 (s, 12H), 2.09 (s,12H), 1.90 (s, 12H), 1.40 (d, 6H). 31 P-NMR (C 6 D 6 ): δ -23.7 (s).12. Hayashi et al., Organometal. Chem. 370, 129 (1989).13. 1 H-NMR (C 6 D 6 ): δ 7.43 – 7.37 (m, 4H), 7.3 – 7.25 (m, 4H), 6.99 – 6.86 (m,12H), 4.55 (s, 2H), 4.39 (m, 2H), 4.10 – 4.03 (m, 2H), 3.21 (m, 2H), 2.06 (s,12H), 1.51 (d, 6H). 31 P-NMR (C 6 D 6 ): δ - 24.2 (s).