Transfer Hydrogenation of In Situ Generated Imines Enables Functionalized Isatin‐Hydrazones

Herein, a transfer hydrogenation of in situ generated imine intermediates from readily available isatin-hydrazones with 1,4-benzoquinones or aldehydes by Brønsted acid catalysis was established. This efficient, mild ambient, operationally simple and safe approach afforded stereospecific functionalized isatin-3-arylhydrazones and isatin-3-alkylhydrazones in excellent yields (up to 95%).