A novel and efficient p-TsOH-promoted cascade cyclization of 2-propynolphenols is developed to give 4-tosyloxy-2H-chromenes in moderate to efficient yields. It is noted that p-TsOH acts not only as a promoter in this reaction, and also as the sulfonate source. Importantly, the obtained 4-tosyloxy-2H-chromenes can be used as versatile intermediates for the synthesis of various functionalized compounds through diverse metal-catalyzed cross-coupling reactions. Moreover, this method can be enlarged to gram scale.

中文翻译：

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酸促进的2-丙炔酚的环化反应生成4-tosyloxy-2 H-苯甲基

开发了新颖且有效的2-丙炔酚酚的p -TsOH-促进的级联环化反应，以中等至有效的产率得到4-甲苯磺酰氧基-2 H-色烯。应当指出，对-TsOH不仅在该反应中起促进剂的作用，而且还起磺酸盐源的作用。重要的是，所获得的4-甲苯磺酰氧基-2 H-色烯可以用作通过各种金属催化的交叉偶联反应合成各种官能化化合物的通用中间体。而且，该方法可以扩大到克级。