We describe a novel and highly efficient metal-free strategy to construct 9,9-disubstituted fluorenes and phenanthrenes via the TfOH-catalyzed cycloisomerizations of o-alkynylbiaryls. Notably, the significant effects of the electronic properties and steric hindrance of the alkyne terminus on the reaction selectivity have been observed.
我们描述了一种新型且高效的无
金属策略,可通过T-OH催化的邻炔基联芳基的环异构化反应来构建9,9-二取代的
芴和
菲。值得注意的是,已经观察到
炔烃末端的电子性质和位阻对反应选择性的显着影响。