Bi(OTf)₃‑Mediated Cycloisomerization of γ‑Alkynyl Arylketones: Application to the Synthesis of Substituted Furans

A novel Bi­(OTf)3-mediated cycloisomerization of γ-alkynyl arylketones 4, 7, or 10 with molecular sieve (MS) in MeNO2 affords 3-substituted furans 3, 8, or 11 at rt for 3 h in moderate to good yields. The method provides mild, less-toxic, atom-economic and efficient conditions. The mechanism has been studied and proposed. Moreover, this route can be enlarged to gram scale.一种新型的以三氟甲磺酸铋(Bi(OTf)3)介导的γ-炔基芳基酮4、7或10与分子筛(MS)在硝基甲烷(MeNO2)中于室温下反应3小时，可得到3-取代呋喃3、8或11，产率为中等到良好。该方法具备温和、低毒、原子经济且高效的反应条件。已对其反应机理进行研究并提出相关假说。此外，该合成路线可拓展至克级规模。