A ligand-free Pd(II)-catalyzed synthesis of quinoxalin-2(1H)-ones has been developed. Pd(TFA)₂ can induce ethyl 2-(N-arylcarbamoyl)-2-chloroiminoacetates to undergo cyclization to afford quinoxalin-2(1H)-one products in high yields in the presence of Na₂CO₃. This catalytic system is also effective to convert α-aryl-α-chloroimino-N-arylamides to the corresponding quinoxalin-2(1H)-one products via tandem N-Cl cleavage and N-arylation in moderate yields. The reaction described herein constitutes simple and effective approach towards quinoxalin-2(1H)-one derivatives.

中文翻译：

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无配体的Pd（II）催化α-氯亚氨基-N-芳基酰胺的环化反应合成喹喔啉-2（1 H）-ones

已经开发了无配体的Pd（II）催化的喹喔啉-2（1 H）-one合成。Pd（TFA）₂可以诱导2-（N-芳基氨基甲酰基）-2-氯亚氨基乙酸乙酯进行环化反应，从而在Na ₂ CO ₃存在下以高收率提供quinoxalin-2（1 H）-one产物。该催化体系还有效地通过串联的N -Cl裂解和N-芳基化以中等收率将α-芳基-α-氯亚氨基-N-芳基酰胺转化为相应的喹喔啉-2（1 H）-一产物。本文所述的反应构成了针对喹喔啉2（1 H）-一阶导数。