ABSTRACT
By properly modifying the coordination sphere of the metal complex steric constraints can be imposed on the reaction permitting regioselective and stereoselective control. Thus, geraniol is regioselectively epoxidized to a monoepoxide with tert Bu02H/VO(acac)2 system
(10.35)
An example of a stereoselective reaction is epoxidation of the homoallylic alcohol to syn-epoxy alcohol, carried out by tert-Bu02H/ Mo(CO)6 system:
(10.36)
Platinum group metals in low oxidation states show the properties of soft centers activating the coordinated hydrocarbon molecule toward nucleophilic attack resulting in an oxidative nucleophilic substitution of hydrogen with a simultaneous two-electron reduction of the metal catalyst. Pd(II) is particularly efficient in this group of oxidative processes [14].
