Enantioselective Ni–Al Bimetallic Catalyzed exo-Selective C–H Cyclization of Imidazoles with Alkenes

A Ni–Al bimetallic catalyzed enantioselective C–H exo-selective cyclization of imidazoles with alkenes has been developed. A series of bi- or polycyclic imidazoles with β-stereocenter were obtained in up to 98% yield and >99% ee. The bifunctional SPO ligand-promoted bimetallic catalysis proved to be critical to this challenging stereocontrol.本研究开发了一种镍-铝（Ni–Al）双金属催化的咪唑类化合物与烯烃间的对映选择性C-H键外选择性环化反应。通过该反应可获得一系列带有β位手性中心的双环或多环咪唑类产物，产物产率最高可达98%，对映体过量值（enantiomeric excess, ee）大于99%。研究证实，双功能SPO配体介导的双金属催化体系对实现该极具挑战性的立体调控至关重要。