Boron-Catalyzed Aromatic C–H Bond Silylation with Hydrosilanes
作者:Yuanhong Ma、Baoli Wang、Liang Zhang、Zhaomin Hou
DOI:10.1021/jacs.6b01349
日期:2016.3.23
Metal-free catalytic C-H silylation of a series of aromatic compounds such as N,N-disubstituted anilines with various hydrosilanes has been achieved for the first time using commercially available B(C6F5)3 as a catalyst. This protocol features simple and neutral reaction conditions, high regioselectivity, wide substrate scope (up to 40 examples), Si-Cl bond compatibility, and no requirement for a hydrogen
A convenient procedure has been developed for the preparation of Group14 compounds by integrated palladium‐catalyzed cross‐coupling of aromatic iodides with the corresponding Group14hydrides in the presence of a base. The reaction conditions can be applied to the cross‐coupling of tertiary, secondary, and primary Group14 compounds. In most cases, the desired arylated products were obtained in synthetically
Brønsted Acid-Promoted Formation of Stabilized Silylium Ions for Catalytic Friedel–Crafts C–H Silylation
作者:Qing-An Chen、Hendrik F. T. Klare、Martin Oestreich
DOI:10.1021/jacs.6b04878
日期:2016.6.29
aromatic substitution with silicon electrophiles is disclosed. A strong Brønsted acid that would usually promote the reverse reaction, i.e., protodesilylation, was found to initiate the C-H silylation of electron-rich (hetero)arenes with hydrosilanes. Protonation of the hydrosilane followed by liberation of dihydrogen is key to success, fulfilling two purposes: to generate the stabilized silylium ion and
Friedel-Crafts-Type Intermolecular C−H Silylation of Electron-Rich Arenes Initiated by Base-Metal Salts
作者:Qin Yin、Hendrik F. T. Klare、Martin Oestreich
DOI:10.1002/anie.201510469
日期:2016.2.24
An electrophilic aromatic substitution (SEAr) with a catalytically generated silicon electrophile is reported. Essentially any commercially available base‐metal salt acts as an initiator/catalyst when activated with NaBArF4 . The thus‐generated Lewis acid then promotes the SEAr of electron‐rich arenes with hydrosilanes but not halosilanes. This new C−H silylation was optimized for FeCl2 /NaBArF4 ,
亲电芳族取代(S Ë报道AR)与催化产生的硅电试剂。当用NaBAr F 4活化时,基本上任何市售的贱金属盐都可作为引发剂/催化剂 。然后,由此产生的路易斯酸会与氢硅烷(而不是卤代硅烷)一起促进富电子芳烃的S E Ar。针对FeCl 2 / NaBAr F 4对这种新的CHH甲硅烷基化进行了优化, 在低至0.5 mol%的催化剂负载下提供了良好的收率。该过程非常简单,与典型的Friedel-Crafts方法非常接近,在该方法中不需要添加碱来吸收释放的质子。