Mechanochemical Organocatalysis: Simple Chiral Primary Diamine‐TfOH‐catalysed Asymmetric Aldol and Robinson Annulation Reactions

Abstract Mechanochemical organocatalysis, which integrates mechanochemistry and organocatalysis to provide a metal‐and solvent‐free synthetic method for synthesizing chiral products, has garnered significant interest recently due to its importance in green chemistry. In this study, simple, unmodified commercially available chiral primary diamines with TfOH were employed as catalysts in mechanochemical direct asymmetric aldol and Robinson annulation reactions. This protocol demonstrated high efficiency, atom economy and high stereoselectivity. Notably, direct asymmetric aldol reactions involving unreactive aromatic methyl ketones, which still is a challenge for mechanochemical organocatalysis, proceeded smoothly. Additionally, chiral 3,5‐diaryl‐cyclohexenones were efficiently synthesized using this mechanochemical asymmetric catalytic protocol and afforded high‐to‐excellent enantioselectivities. These findings highlight the potential of mechanochemical organocatalysis for asymmetric catalysis.