Cinchona Alkaloids Derivatives Catalyzed Sulfenylated Reaction And Mannich Reaction

Asymmetric organocatalysis has been a frontier in the field of chiral molecule synthesis. Thecomparable advantages, including mild reaction conditions, environment benign, and the facile recovery ofcatalysts. Cinchona alkaloids, which contain both acid and base founctional groups, are natural asymmetriccatalyst with widespread applications in organic synthesis. This paper introduces the alkaloid derivativescatalyzed sulfinylation of3-Aryloxindoles and asymmetric Mannich reaction of5H-oxazole-4-one. Themain contents include:An organocatalytic asymmetric sulfenylation of3-aryloxindoles with N-(sulfanyl)succinimides hasbeen developed by using commercially available (DHQD)2PHAL as catalyst. Various chiral3-benzylthio-,alkylthio-, and arylthio-substituted oxindoles, containing3,3-disubstituted quarternary carbon stereocenters,could be obtained in high enantioselectivities (85–97%ee). Furthermore, the opposite enantiomers of thesulfenylated products were readily accessible with equal excellent enantioselectivities (86–95%ee) byreplacing the catalyst with (DHQ)2PHAL.The first organocatalytic Mannich reaction of5H-oxazol-4-ones with various readily preparedaromatic and aliphatic sulfonimides has been developed. Two commercially available pseudoenantiomericcinchona alkaloids-derived tertiary amine/ureas have been demonstrated as the most efficient catalysts toaccess the opposite enantiomers of the Mannich products with equally excellent stereoselectivities. Fromthe Mannich adducts, important α-methyl-α-hydroxy β-amino acid derivatives, such as the α-methylatedC-13side chain of Taxol and Taxotere can be conveniently prepared.