Synthesis of Diverse β,β‐Diaryl β‐Siloxy Diamines and Application as Organocatalysts

Abstract

β,β‐Diaryl‐β‐siloxy diamines were developed as a tunable scaffold for structurally diverse diamine‐based organocatalysts. Synthesis was initiated with the reaction of an oxazolidine methyl ester from L‐serine with various Grignard reagents, introducing a wide range of diaryl substituents at the β‐position. By adjusting the reaction sequence of the silylation and amination steps, the developed synthetic approach enabled the incorporation of diverse aryl, silyl, and amine groups, including cyclic, acyclic tertiary, and secondary amines, into 1,2‐diamines. The resulting diamines were evaluated as catalysts in the enantioselective fluorination of β‐diketones in water using NFSI. Although the yield was similar to that of the conventional catalyst C1, the enantioselectivity was improved, reaching up to 53% ee.