Exo-Selective Intramolecular C–H Alkylation with 1,1-Disubstituted Alkenes by Rare-Earth Catalysts: Construction of Indanes and Tetralins with an All-Carbon Quaternary Center

We report herein the exo-selective,
regiospecific annulation of
a wide range of functionalized aromatic substrates with 1,1-disubstituted
alkenes through C­(sp2)–H and benzylic C­(sp3)–H activation by half-sandwich rare-earth catalysts. This
protocol offers a straightforward and atom-efficient route for the
synthesis of a family of indane and tetralin derivatives bearing an
all-carbon quaternary stereocenter that were difficult to access previously
by other catalysts. The reaction mechanism has been elucidated by
deuterium-labeling experiments and DFT calculations.

本报告揭示了通过半夹心稀土催化剂对C(sp2)–H和苄基C(sp3)–H的活化，对多种功能化芳香底物与1,1-二取代烯烃进行区域选择性偶联反应的研究。该方案提供了一种简便且原子经济性高的合成途径，用于制备一类难以通过其他催化剂获得的、含有全碳季碳立体中心的吲哚烷和四氢萘衍生物家族。反应机理已通过氘标记实验和密度泛函理论计算得到阐明。