The chemoselective [4+2] annulation/aromatization reactions between benzofuran-derived azadienes and N-Ts cyanamides are developed, affording a convenient method for synthesizing benzofuro[3,2-d]pyrimidin-2-amines under mild conditions. Herein, N-Ts cyanamides selectively participated in reactions absolutely via carbodiimide anion intermediates and the corresponding cyanamide anion intermediates derived products were not observed. The proposed chemoselective stepwise reaction mechanism was well supported by DFT calculations.

中文翻译：

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通过苯并呋喃衍生的氮杂二烯和碳二亚胺阴离子的一锅级联[4 + 2]环化/芳构化直接合成苯并呋喃[3,2-d]嘧啶-2-胺


发展了苯并呋喃衍生的氮杂二烯与N-Ts氰胺之间的化学选择性[4+2]环化/芳构化反应，为在温和条件下合成苯并呋喃并[3,2-d]嘧啶-2-胺提供了一种简便的方法。其中，N-Ts氰胺完全通过碳二亚胺阴离子中间体选择性参与反应，并且没有观察到相应的氰胺阴离子中间体衍生产物。所提出的化学选择性逐步反应机制得到了 DFT 计算的良好支持。