多相光催化已成为有机合成中强大且可持续的技术;然而,石墨氮化碳(gC 3 N 4)作为非均相光催化剂用于有机转化的应用仍处于起步阶段。化学家正在积极致力于开发由 gC 3 N 4催化的新型有机转化,但这仍然具有挑战性。在此,我们描述了可见光驱动的 gC 3 N 4催化的炔烃原子转移自由基加成(ATRA)来合成有价值的(E)-β-硫代/硒基乙烯基砜。该方法具有非均相光催化、优异的区域和立体选择性、100%原子经济性、不含金属和添加剂的性质,以及覆盖(杂)芳基和烷基炔烃,特别是工业原料丙炔的广泛底物范围。此外,该方法还可应用于复杂分子的后期功能化。值得注意的是,gC 3 N 4可以在五次运行中回收并重复使用,而不会损失催化活性。机理研究表明该反应是通过能量转移过程而不是单个电子转移发生的。
Selectivity control in thiol–yne click reactions <i>via</i> visible light induced associative electron upconversion
作者:Julia V. Burykina、Nikita S. Shlapakov、Evgeniy G. Gordeev、Burkhard König、Valentine P. Ananikov
DOI:10.1039/d0sc01939a
日期:——
An associative electron upconversion is proposed as a key step determining the selectivity of the thiol–yne coupling.
提出了一种关联电子上转换作为决定硫醇-炔偶联选择性的关键步骤。
Pd-Catalyzed Alkenyl Thioether Synthesis from Thioesters and <i>N</i>-Tosylhydrazones
作者:Kota Ishitobi、Kei Muto、Junichiro Yamaguchi
DOI:10.1021/acscatal.9b04212
日期:2019.12.6
A Pd-catalyzed alkenyl thioethersynthesis was achieved using thioesters and N-tosylhydrazones as starting materials. The thioester acted as an efficient “sulfur source” for catalytic C–S bond formation using N-tosylhydrazone. This method gave Z-alkenyl thioethers with high diastereoselectivity (up to 99:1 diastereomeric ratio). This transformation displayed a wide functional group tolerance and was
We describe here an efficient route for the synthesis of (Z)-vinylic sulfides 3 via the highly regio- and stereoselective coupling of (Z)-1,2-bis(aryl(alkyl)thio)alkenes and Grignard reagents over a Ni catalyst under mild conditions. (Z)-Vinylic sulfides 3 are important intermediates in the synthesis of tri- and tetrasubstituted alkenes that are important construction blocks for drugs and natural products
我们在这里描述了通过Ni催化剂上的(Z)-1,2-双(芳基(烷基)硫代)烯烃和格氏试剂的高度区域选择性和立体选择性偶联来合成(Z)-乙烯基硫化物3的有效途径在温和的条件下。(Z)-Vinylic硫化物3是三和四取代烯烃合成的重要中间体,这是药物和天然产物的重要结构单元。可以使用H 2 O 2将定向有机硫基团(SR)转化为二芳基(烷基)二硫化物(RSSR)。作为氧化剂,避免了硫资源的浪费。该协议提供了一种高度区域选择性和立体选择性的通用方法,用于合成多种三取代和四取代的烯烃。
Electrophilic Activation of S−Si Reagents by Silylium Ions for Their Regio‐ and Diastereoselective Addition Across C−C Multiple Bonds
作者:Honghua Zuo、Elisabeth Irran、Hendrik F. T. Klare、Martin Oestreich
DOI:10.1002/anie.202401599
日期:2024.4.8
An in situ-generated bissilylated sulfonium ion is the actual catalyst in highlyregio- and diastereoselectiveaddition reactions of thiosilanes across the C−C multiple bonds of alkynes and allenes, respectively (see scheme). These thiosilylation reactions enable the direct installation of two orthogonal linchpins for further chemoselective functional-group manipulation.