Wang Shou-Guo, Park Sung Hwan, Cramer Nicolai
Laboratory of Asymmetric Catalysis and Synthesis, EPFL SB ISIC LCSA, BCH 4305, 1015, Lausanne, Switzerland.
Angew Chem Int Ed Engl. 2018 May 4;57(19):5459-5462. doi: 10.1002/anie.201802244. Epub 2018 Apr 6.
Chiral cyclopentadienyl (Cp ) ligands have a large application potential in enantioselective transition-metal catalysis. However, the development of concise and practical routes to such ligands remains in its infancy. We present a convenient and efficient two-step synthesis of a novel class of chiral Cp ligands with tunable steric properties that can be readily used for complexation, giving Cp Rh , Cp Ir , and Cp Ru complexes. The potential of this ligand class is demonstrated with the latter in the enantioselective cyclization of azabenzonorbornadienes with alkynes, affording dihydrobenzoindoles in up to 98:2 e.r., significantly outperforming existing binaphthyl-derived Cp ligands.
手性环戊二烯基（Cp）配体在对映选择性过渡金属催化中具有巨大的应用潜力。然而，开发简洁实用的此类配体合成路线仍处于起步阶段。我们报道了一种便捷高效的两步法合成新型手性Cp配体，其空间性质可调，可轻松用于络合反应，生成CpRh、CpIr和CpRu配合物。通过后者在氮杂苯并降冰片二烯与炔烃的对映选择性环化反应中展示了这类配体的潜力，得到对映体比例高达98:2的二氢苯并吲哚，显著优于现有的联萘衍生的Cp配体。
