Tin-containing hydrotalcite-like compounds as catalysts for the Meerwein–Ponndorf–Verley reaction

• Calcination products of hydrotalcites are excellent catalyst for MPV reaction.
• The presence of tin in the hydrotalcite improves the catalytic activity.
• A concerted mechanism is proposed that explains the catalytic results.

Hydrotalcite-like compounds (HTs) containing Mg/Al or Mg/Al/Sn were prepared and used as precursors to obtain basic catalysts by calcination at 450 °C. The catalysts were used in the Meerwein–Ponndorf–Verley (MPV) reaction of benzaldehyde and cyclohexanone in the presence of 2-propanol as hydrogen donor. The mixed oxide obtained by calcining the tin-containing HT was found to be more catalytically active than that obtained from the Mg/Al HT and the pure magnesium oxide. This result can be ascribed to the mechanism of the reaction, which involves acid–base sites on the catalyst surface. The most active catalyst was used in the MPV reactions of other carbonyl compounds including aldehydes and ketones with excellent conversion and selectivity.

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