Catalysis by first-row transition metals is of increasing interest in the context of the scarcity of chemical resources. For instance, iron is promising due to its abundance, low toxicity and unique electronic features. Here we synthesized quinazoline alkaloids from alkynoic acids and functionalized amines in the presence of iron dibromide and pyridine in toluene or, alternatively, in a solventless reaction system. We studied iron sources, reaction media and the effect of additives. Results show 39–99% yields and regioselective preparation of nitrogen- and oxygen-containing scaffolds. This is the first example of a cascade process involving alkynoic acids catalyzed by iron. Fe is more abundant, cheaper and less toxic than other Au, Cu and Ru catalysts previously reported for similar transformations.

在化学资源稀缺的背景下，第一行过渡金属的催化作用越来越受到关注。例如，铁因其丰富、低毒性和独特的电子特性而很有前景。在这里，我们在二溴化铁和吡啶的存在下，在甲苯中或在无溶剂反应体系中，由炔酸和官能化胺合成喹唑啉生物碱。我们研究了铁源、反应介质和添加剂的影响。结果显示含氮和含氧支架的产率和区域选择性制备为 39-99%。这是涉及由铁催化的炔酸的级联过程的第一个例子。与之前报道的用于类似转化的其他 Au、Cu 和 Ru 催化剂相比，Fe 更丰富、更便宜且毒性更小。