Chemoselective Synthesis of Acyclic Acetals by Natural Kaolin under Green Chemistry Conditions

摘要

The highly chemoselective protection of various aldehydes by natural kaolin as a catalyst was reported. This clay was characterised by XRD, FTIR, BET and SEM techniques. The acetalization reaction was executed in ethanol as solvant and produces the corresponding acetals with moderate to excellent yields and high chemoselectivity (0%< yield < 95%). The reaction could be performed on a gram scale using the kaolin catalyst. The thermodynamic and kinetic studies on the reaction were conducted on the m-nitrobenzaldehyde. Algerian kaolin using for the first time in organic synthesis is an efficient heterogeneous catalyst, recyclable who can be used at the multi-gram scale. This is a low cost and very eco-friendly heterogeneous catalyst.