Activating Highly Hindered Anhydrides for Use in Masking Alcohols and Polyols – A New Method Inspired by Cationic Palladium

Abstract A new method inspired by cationic palladium (II) species in activating highly hindered acid anhydrides in masking alcohols and polyols is described. This protocol utilizes a cationic palladium catalyst Pd(PhCN)2(OTf)2 generated in situ from Pd(PhCN)2Cl2 and AgOTf to activate highly hindered acid anhydrides and to direct the acylation process. This new method is highly efficient and proceeds with only 1 mol% of the catalyst loading at mostly room temperature. The method has a wide substrate scope in masking different alcohols and polyols with robust protecting groups in good to excellent yields.