A Highly Selective Pd(OAc)2/Pyridine/K2CO3 System for Oxidation of Terpenic Alcohols by Dioxygen

Abstract  

Molecular sieves, complex organic bases and radical oxidants are commonly used in alcohols oxidation reactions. In this work, we have evaluated the beneficial effects of addition of K₂CO₃ to Pd(II)-catalyzed oxidation alcohols, which resulted in a remarkable increase in the oxidation reaction rates without selectivity losses. Herein, in a metallic reoxidant-free system, terpenic alcohols (β-citronellol, nerol and geraniol) were selectively converted into respective aldehydes from Pd(II)-catalyzed oxidation reactions in presence of dioxygen. High conversions and selectivities (greater than 90%) were achieved in the presence of the Pd(OAc)₂/K₂CO₃ catalyst and pyridine excess. The exogenous role of others auxiliary anionic and nitrogen compounds was appraised.