A-coupling and decarboxylative A-coupling is an important protocol for constructing propargylamines. However, the development of metal-free (decarboxylative) A-coupling is still challenging. Herein, we describe a doubly decarboxylative coupling of amino acids, propiolic acids, and aldehydes under metal-free conditions. It is worth noting that choosing the kind of aldehydes is crucial for controlling the chemoselectivity of the reaction. The use of glyoxylate ester furnished ester-containing propargylamines in good yield via a cascade process of decarboxylation and decarboxylative coupling. Both aliphatic and aromatic aldehydes were transformed into the decarboxylative A-coupling products.

中文翻译：

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无过渡金属的 Csp3–Csp 氨基酸和丙炔酸的双脱羧偶联

A-偶联和脱羧 A-偶联是构建炔丙胺的重要方案。然而，无金属（脱羧）A-偶联的开发仍然具有挑战性。在此，我们描述了在无金属条件下氨基酸、丙炔酸和醛的双重脱羧偶联。值得注意的是，选择醛的种类对于控制反应的化学选择性至关重要。乙醛酸酯的使用通过脱羧和脱羧偶联的级联过程以良好的收率提供了含酯的炔丙胺。脂肪族醛和芳香族醛均转化为脱羧A-偶联产物。