Rhodium(III)-Catalyzed Annulation of Acetophenone O‑Acetyl Oximes with Allenoates through Arene C–H Activation: An Access to Isoquinolines

Rhodium­(III)-catalyzed annulation of acetophenone O-acetyl oximes with allenoates was achieved, affording isoquinolines in good to excellent yields with high regioselectivities under redox-neutral conditions. Allenoates acted as the C2 synthons in the annulation reaction. The present synthetic methodology features good functional group tolerance and avoids metal salts as the external oxidants. The proposed mechanism suggests that the reaction proceeds through arene C–H activation, allene insertion, and C–N coupling.本研究成功实现了铑(III)催化苯乙酮O-乙酰基肟与丙二烯酸酯的环化反应，在氧化还原中性条件下以良好至优异的收率及高区域选择性得到异喹啉类产物。该反应中丙二烯酸酯作为C2合成子参与环化过程。本合成方法具有良好的官能团耐受性，且无需使用外部金属盐氧化剂。所提出的反应机理表明，该过程依次经历芳烃C-H活化、丙二烯插入以及C-N偶联步骤。