反应详情

An optically active binaphthol (VII) as a starting material is reacted by a method described in the literature (M. Vondenhof and J. Mattay, Tetrahedron Lett., 1990, Vol. 31, pp . 985-988; L. Kurz, G. Lee, D. Morgans, Jr., M. J. Waldyke, and T. Ward, Tetrahedron Lett., 1990, Vol. 31, pp. 6321-6324) and by a method described in the literature (Y. Uozumi, A. Tanahashi, S. -Y. Lee, and T. Hayashi, J. Org. Chem., 1993, Vol. 58, pp. 1945-1948). That is, the binaphthol (VII) is reacted with trifluoromethanesulfonic anhydride (Tf2O) using pyridine in methylene chloride to convert compound (VII) to 2,2′-bis(trifluoromethanesulfonyl-oxy)-1,1′-binaphthyl (VIII), which is reacted with diphenylphosphine oxide (Ph2PHO) in the presence of a catalytic amount of a palladium-phosphine complex, whereby 2′-diphenylphosphinyl-2-trifluoromethanesulfonyloxy-1,1′-binaphthyl (IX) can be synthesized. Compound (IX) is hydrolyzed with lithium hydroxide (LiOH) to obtain 2′-diphenylphosphinyl-2-hydroxy-1,1′-binaphthyl (XVIII), which is brominated in dioxane to obtain 2′-diphenylphosphinyl-2-hydroxy-6-bromo-1,1′-binaphthyl (XIX). Compound (XIX) is reduced with trichlorosilane (HSiCl3) to obtain 2′-diphenylphosphino-2-hydroxy-6-bromo-1,1′-binaphthyl (XX), which is reacted with 2-vinyl-5,5-dimethyl-1,3-dioxa-2-borinane using a palladium catalyst by a method described in the literature (Y. Miyaura and A. Suzuki, J. C. S. Chem. Commun., 1979, p. 866) to obtain 2′-diphenylphosphino-2-hydroxy-6-vinyl-1,1′-binaphthyl (XXI).

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