Bromotrimethylsilane (TMSBr)-promoted intramolecular cyclization of (o-arylethynyl)benzyl ethers to form 1H-isochromenes at room temperature is reported. Further studies indicated that vinyl carbocations are the reaction intermediates which are stabilized by the conjugated aryl groups. Thus, O-addition of benzyl ethers/tetrahydropyrans to alkynes was achieved under metal-free, acidic conditions. These
报道了
溴代三甲基
硅烷 (TMSBr) 促进的 ( o -arylethynyl) 苄基醚在室温下分子内环化形成 1 H-异色烯。进一步的研究表明,
乙烯基碳阳离子是由共轭芳基稳定的反应中间体。因此,在无
金属、酸性条件下实现了苄基醚/
四氢吡喃与
炔烃的O-加成。这些反应条件与炔基普林斯反应相容;因此,使用一锅法直接由炔基
苯甲醛和炔醇生产1 H-异色烯。