Cu–Ag/hydrotalcite catalysts for dehydrogenative cross-coupling of primary and secondary benzylic alcohols

Abstract

The development of new and inexpensive heterogeneous catalysts for direct C–C cross-coupling of primary and secondary alcohols is a challenging goal and has great importance in academic and industrial sectors. In this work Cu–Ag/hydrotalcite (Cu–Ag/HT) catalysts were prepared and tested for their impact on this cross-coupling. The effect of supports, including MgO, γ-Al₂O₃ and HT with different Mg : Al molar ratios, was investigated. It was found that the acidic or basic properties of the supports affected product selectivity. The roles of Cu and Ag sites in the cross-coupling were also investigated with the prepared Cu–Ag/HT catalyst demonstrating high activity and selectivity for the reaction. The yield-to-target product of β-phenylpropiophenone reached 99% after 1 h under optimum reaction conditions. The stability in air and reusability studies show that Cu–Ag/HT can be stored for 6 days and can be used five times without apparent deactivation, respectively.