Water‐Tolerant and Reusable Catalysts for Direct Ester Condensation between Equimolar Amounts of Carboxylic Acids and Alcohols

ZrOCl2⋅8 H2O and HfOCl2⋅8 H2O are highly effective, water‐tolerant, and reusable homogeneous catalysts for direct ester condensation between equimolar amounts of carboxylic acids and alcohols. Notably, zirconium(IV) salts such as ZrOCl2⋅8 H2O and Zr(OAc)x(OH)y are potential green catalysts due to their low toxicity, commercial availability at low cost, ease of handling, high catalytic activity, and reusability.