Selective Removal of Aminoquinoline Auxiliary by IBX Oxidation

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.8-氨基喹啉（8-Aminoquinoline，AQ）是金属催化导向C-H官能团化反应中广泛使用的双齿导向辅助基团。本文报道了一种高效且具有化学选择性的方法：在水与六氟异丙醇（HFIP）的混合溶剂体系中，通过化学计量比的2-碘酰基苯甲酸氧化剂，或催化量的2-碘苯甲酸与Oxone复合氧化剂的作用，可将各类N-喹啉基甲酰胺转化为一级酰胺。该方法对邻苯二甲酰亚胺基保护的α-氨基酸（α-amino acid，αAA）底物具有独特的兼容性，进一步提升了AQ导向的钯催化C-H官能团化策略用于复杂α-氨基酸合成的整体应用价值。