Synthesis of 1,4-bis(9-O-quininyl)phthalazine and its application as a ligand to the catalytic asymmetric dihydroxylation of olefins

An improved procedure for the preparation of 1,4-bis(9-O-quininyl) phthalazine [(QN)(2)PHAL] and the rudimentary application of (QN)(2)PHAL to the catalytic asymmetric dihydroxylation of olefins were described. (QN)(2)PHAL was synthesized in a good yield by the reaction of quinine with 1, 4-dichlorophthalazine in the presence of K2CO3 and KOH in refluxing toluene. The asymmetric dihydroxylation of four olefins with (QN)(2)PHAL as the chiral ligand showed an excellent enantioselectivity and activity.