A new bifunctional catalyst for tandem Heck-asymmetric dihydroxylation of olefins

A new bifunctional catalyst consisting of active palladium and osmium species anchored on silica gel through a mercaptopropyl spacer and a cinchona alkaloid respectively has been prepared for the first time and used in the heterogeneous tandem Heck-asymmetric dihydroxylation of olefins to afford diols with excellent yields and enantiomeric excesses (ee's) in presence of N-methylmorpholine Noxide or K3Fe(CN)6 as cooxidants