Asymmetric Allylic C-H Oxidation for the Synthesis of Chromans
Pu-Sheng Wang1, Peng Liu1, Yu-Jia Zhai1
1Hefei National Laboratory for Physical Sciences at the Microscale and Department of Chemistry, University of Science and Technology of China , Hefei 230026, China.
Abstract:
An enantioselective intramolecular allylic C-H oxidation to generate optically active chromans has been accomplished under the cooperative catalysis of a palladium complex of chiral phosphoramidite ligand and 2-fluorobenzoic acid. Mechanistic studies suggest that this reaction commences with a Pd-catalyzed allylic C-H activation event and then undergoes asymmetric allylic alkoxylation. The synthetic significance of the method has been embodied by concisely building up a key chiral intermediate to access (+)-diversonol.
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