An efficient method for the bismuth‐catalyzed regioselective synthesis of pyranocoumarins and furocoumarins has been developed from the reaction of 4‐hydroxycoumarins with propargyl alcohols. The reaction proceeds through sequential propargylation and intramolecular cyclization reactions catalyzed by bismuth(III) triflate.

中文翻译：

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从4-羟基香豆素和炔丙醇的区域选择性铋催化合成吡喃香豆素和呋喃香豆素

4-羟基香豆素与炔丙醇的反应已开发出一种高效的铋催化吡喃香豆素和呋喃香豆素的区域选择性合成方法。该反应通过三氟甲磺酸铋（III）催化的顺序炔丙基化和分子内环化反应进行。