“…In the recent years, heterogeneous catalysts had also been reported which most of these catalytic systems are present acidic nature . Metal oxides such as Al 2 O 3 , Fe 3 O 4 , SnO, ZnO, CaO, ZnO–La 2 O 3 , sulfated zirconia, sulfated carbon, copper methanesulfonate, Fe2(SO4)3, Zn(ClO4)2/MgSO4, zirconium titanium phosphate, Zno/SiO2, N,N‐diphenylammoniumtriflate and p‐ dodecylbenzenesulfonic acid were used for catalytic synthesis of esters from carboxylic acids and alcohols. In the past ten years, direct esterification of aldehydes with alcohols by using stoichiometric amounts of strong oxidants have also been reported .…”