Fan Chao, Dhawa Uttam, Qian Deyun, Sakic Davor, Morel Jennifer, Hu Xile
Laboratory of Inorganic Synthesis and Catalysis, Institute of Chemical Sciences and Engineering, École Polytechnique Fédérale de Lausanne, ISIC-LSCI, BCH 3305, 1015, Lausanne, Switzerland.
University of Zagreb, Faculty of Pharmacy and Biochemistry, Ante Kovačića 1, 10000, Zagreb, Croatia.
Angew Chem Int Ed Engl. 2024 Jul 15;63(29):e202406767. doi: 10.1002/anie.202406767. Epub 2024 Jun 14.
Cyclic sulfones have demonstrated important applications in drug discovery. However, the catalytic and enantioselective synthesis of chiral cyclic sulfones remains challenging. Herein, we develop nickel-catalyzed regiodivergent and enantioselective hydroalkylation of sulfolenes to streamline the synthesis of chiral alkyl cyclic sulfones. The method has broad scope and high functional group tolerance. The regioselectivity can be controlled by ligands only. A neutral PYROX ligand favors C3-alkylation whereas an anionic BOX ligand favors C2-alkylation. This control is kinetic in origin as the C2-bound Ni intermediates are always thermodynamically more stable. Reactivity study of a wide range of relevant Ni intermediates reveal a Ni/Ni catalytic cycle with a Ni-H species as the resting state. The regio- and enantio-determining step is the insertion of this Ni-H species into 2-sulfolene. This work provides an efficient catalytic method for the synthesis of an important class of organic compounds and enhances the mechanistic understanding of Ni-catalyzed stereoselective hydroalkylation.
环状砜类化合物在药物研发中已展现出重要应用。然而,手性环状砜的催化及对映选择性合成仍然具有挑战性。在此,我们开发了镍催化的环丁烯砜区域发散性对映选择性氢烷基化反应,以简化手性烷基环状砜的合成。该方法适用范围广,对官能团耐受性高。区域选择性仅可通过配体来控制。中性的PYROX配体有利于C3-烷基化,而阴离子型BOX配体则有利于C2-烷基化。这种控制源于动力学因素,因为与C2相连的镍中间体在热力学上总是更稳定。对一系列相关镍中间体的反应性研究揭示了一个以Ni-H物种为静止态的Ni/Ni催化循环。区域和对映选择性决定步骤是该Ni-H物种插入2-环丁烯砜中。这项工作为一类重要有机化合物的合成提供了一种高效的催化方法,并增进了对镍催化立体选择性氢烷基化反应机理的理解。