La(NO3)3.6H2O was used as an efficient catalyst for highly diastereoselective synthesis of functionalized
piperidines by one-pot five-component reactions of anilines and aromatic aldehydes with acetoacetic esters. This strategy
proceeds by way of the Knoevenagel reaction followed by inter-molecular aza-Diels-Alder reaction. The main features of
the current method comprise mild reaction conditions, easy work-up, eco-friendliness, high atom economy, short times
and the products were isolated with high yields.