American Chemical Society
jo9b01362_si_002.cif (534.01 kB)

Selective Removal of Aminoquinoline Auxiliary by IBX Oxidation

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posted on 2019-06-06, 00:00 authored by Zhiguo Zhang, Xiang Li, Mengmeng Song, Yameng Wan, Dan Zheng, Guisheng Zhang, Gong Chen
8-Aminoquinoline (AQ) is a widely used bidentate auxiliary in metal-catalyzed directed C–H functionalization reactions. Herein, we report an efficient and chemoselective method to convert various N-quinolyl carboxamides to primary amides with the treatment of a stoichiometric amount of 2-iodoxybenzoic acid oxidant or the combination of a catalytic amount of 2-iodobenzoic acid and Oxone co-oxidant in mixed solvents of H2O and HFIP. Its unique compatibility with the Phth-protected α-amino acid (αAA) substrates enhances the overall synthetic utility of the AQ-directed palladium-catalyzed C–H functionalization strategy for synthesis of complex αAAs.