ASYMMETRIC ALLYLIC ALKYLATION WITH PALLADIUM COORDINATED TO A NEW OPTICALLY-ACTIVE PYRAZOLYLMETHANE LIGAND

The optically active pyrazole 4R-methyl-7R-isopropyl-4,5,6,7-tetrahydro-indazole, 3, was prepared from (-)-menthone 1, and used for the preparation of the ligands bis(4R-methyl-7R-isopropyl-4,5,6,7-te-trahydro-N2-indazolyl)methane, 5, bis(4R-methyl-7R-isopropyl-4,5,6,7-tetrahydro-N1,N2-indazolyl)methane, 6, and bis(4R-methyl-7R-isopropyl-4,5,6,7-tetrahydro-N1-indazolyl)methane, 7. Their complexes [Pd(eta3-C3H5)(LL)][PF6] (LL = 5, 6 and 7); 9, 10, and 11, respectively, were used as catalyst precursors for the reaction of rac-(E)-1,3-diphenyl-3-acetoxy-1-propene, 12, with dimethylmalonate, 13. When ligand 6 was used methyl 2-carbomethoxy-3,5-diphenyl-4-enoate, 15, was obtained in 84% ee; it was shown that to achieve high ee value it is necessary to have 1 equivalent of chloride ion in the reaction mixture.