The Enantiopure 1,2-Diphenylethylenediamine (DPEDA) Motif in the Development of Organocatalysts for Asymmetric Reactions: Advances in the Last 20 Years

1,2-Diphenylethylenediamine (DPEDA) is a privileged chiral scaffold being used in the construction of a broad variety of organocatalysts and ligands for enantioselective organic reactions. This molecule gave a significant contribution in the synthesis of structurally different bi/multifunctional organocatalysts. DPEDA played an essential role in the development of organocatalysts capable of yielding important information on the different reaction mechanisms, like enamine, iminium, hydrogen-bonding and anion-binding catalysis. The aim of the present review is to highlight and summarize the achievements reached in the last 20 years (2004–2024) in the chemistry of DPEDA-based organocatalysts for asymmetric synthesis.