Bifunctional catalysts stabilized on nanocrystalline magnesium oxide for one-pot synthesis of chiral diols

New bifunctional catalysts composed of PdCl42-, OsO42- and OsO42-, WO42- designed and prepared by a counterionic stabilization technique involving the reactions of Na2PdCl4-K2OsO4 and K2OsO4-Na2WO4 with nanocrystalline MgO are well characterized. These bifunctional catalysts, NAP-Mg-PdOs and NAP-Mg-OsW perform tandem Heck asymmetric dihydroxylation and asymmetric dihydroxylation-N-oxidation reactions, respectively, in the presence of the chiral ligand 1,4-bis(9-o-dihydroquinidinyl)phthalazine [(DHQD)(2)PHAL] in a single pot. It is quite impressive to note that H,02 is used as a terminal oxidant to provide N-methylmorpholine N-oxide (NMO) in situ by the oxidation of N-methylmorpholine (NMM) in the asymmetric dihydroxylation-N-oxidation catalyzed by NAP-Mg-OsW.