Organocatalytic asymmetric Mannich reactions of 5H-oxazol-4-ones : highly enantio- and diastereoselective synthesis of chiral α-alkylisoserine derivatives

• Main Authors: Han, Zhiqiang, Yang, Wenguo, Tan, Choon-Hong, Jiang, Zhiyong
• Other Authors: School of Physical and Mathematical Sciences
• Format: Article
• Language: English
• Published: 2014
• Subjects: DRNTU::Science::Chemistry::Organic chemistry
• Online Access: https://hdl.handle.net/10356/102543; http://hdl.handle.net/10220/19084
• Institution: Nanyang Technological University

The first organocatalytic Mannich reaction of 5H-oxazol-4-ones with various readily prepared aryl- and alkylsulfonimides has been developed. Two commercially available pseudoenantiomeric Cinchona alkaloids-derived tertiary amine/ureas have been demonstrated as the most efficient catalysts to access the opposite enantiomers of the Mannich products with equally excellent enantio- and diastereoselectivities. From the Mannich adducts, important α-methyl-α-hydroxy-β-amino acid derivatives, such as the α-methylated C-13 side chain of taxol and taxotere, can be conveniently prepared.