Novel β‐amino Amide Organocatalysts for the Synthesis of Pharmaceutically Relevant Oxindoles

In this work, a series of novel organocatalysts derived from unique unnatural β‐amino acid scaffold were synthesized and further developed to enhance the desired catalytic properties. Their evaluation was carried out in the asymmetric crossed‐aldol condensation of isatin and enolizable ketone donors. Following a systematic study of the reaction parameters including variations of additive, solvent, temperature, catalyst loading and substrate scope, (1R,2R)‐2‐amino‐N‐((R)‐1‐phenylethyl)cyclohexane carboxamide 9 proved particularly successful, affording the corresponding 3‐hydroxy‐3‐alkyl‐2‐oxindole in excellent yield (>99%) and distereoselectivity (>99% dr) with good enantioselective control (up to 52% ee) in the presence of p‐nitrophenol and EtOH in