Hantzsch esters, which are products of the Hantzsch Dihydropyridine Synthesis, are mild reducing agents, that are often used in transfer hydrogenations of activated C=C bonds, C=O bonds in carbonyl compounds, and C=N bonds in imines. The presence of a Lewis or Brønstedt acid catalyst for further activation of the hydrogen acceptor is often required. In case of chiral catalysts, transfer hydrogenations can occur enantioselectively.

J. AM. CHEM. SOC. 2008, 130, 18-19