Metal-free Brّnsted acids catalyzed synthesis of functional 1,4-dihydropyridines

Brønsted acids catalyze the addition of β-enaminoacrylates to α,β-unsaturated aldehydes leading to substituted dihydropyridines in moderate to good yields under mild conditions. The first example of an enantioselective synthesis of a dihydropyridine is also reported.