Bifunctional Nanoscopic Catalysts for the One-Pot Synthesis of (±)-Menthol from Citral

Active and selective bifunctional Me(Ir, Pd)/beta zeolite and doped nanoscopic hydroxylated fluorides (0.1 % Pd (or Pt)/AlF3) catalysts were developed for the one-pot synthesis of menthols from citral. In the case of fluoride catalysts, the strong electron-withdrawing effect of the dominating fluoride environment depletes the metal surface from electrons and hence, favours the hydrogenation of the C=C bond to citronellal on both Pd and Pt-based catalysts.