B(C<sub>6</sub>F<sub>5</sub>)<sub>3</sub>-Catalyzed Synthesis of Benzofused-Siloles
作者:Liam D. Curless、Michael J. Ingleson
DOI:10.1021/om501033p
日期:2014.12.22
a weak base forms silafluorenes with H2 as the only byproduct. Attempts to extend this approach to synthesize siloles derived from 2,2′-bithiophenes and N-Me-2-Ph-indole resulted in competing reactivity, including protodesilylation. B(C6F5)3 also catalyzed the one-pot, two-step formation of silaindenes from aryl-alkynes by alkyne trans-hydrosilylation, followed by an intramolecular Sila-Friedel–Crafts
由B(C 6 F 5)3和弱碱催化的2-(SiR 2 H)-联苯的脱氢硅烷化反应形成了以H 2为唯一副产物的硅芴。尝试将该方法扩展为合成由2,2'-联噻吩和N -Me-2-Ph-吲哚衍生的甲硅烷导致竞争的反应性,包括原去甲硅烷基化。B(C 6 F 5)3还催化了炔烃的反式氢化硅烷化作用,由芳基炔烃一锅,两步形成硅氢化茚,然后通过弱碱促进了分子内Sila-Friedel-Crafts反应。
Synthesis of Silicon and Germanium-Containing Heterosumanenes via Rhodium-Catalyzed Cyclodehydrogenation of Silicon/Germanium–Hydrogen and Carbon–Hydrogen Bonds
three-step synthesis of C3-symmetric trisilasumanene and trigermasumanene, heteroanalogues of the π-bowl sumanene, was achieved using a threefold rhodium-catalyzed cyclodehydrogenation of Si/Ge–H and C–H bonds as the key step. Trigermasumanene was proven to adopt a planar geometry by single crystal X-ray diffraction for the first time. The optical properties were also investigated by UV–vis and fluorescence
<sup>183</sup>
W NMR Spectroscopy Guides the Search for Tungsten Alkylidyne Catalysts for Alkyne Metathesis
作者:Julius Hillenbrand、Markus Leutzsch、Christopher P. Gordon、Christophe Copéret、Alois Fürstner
DOI:10.1002/anie.202009975
日期:2020.11.23
Triarylsilanolates are privileged ancillary ligands for molybdenum alkylidyne catalysts for alkynemetathesis but lead to disappointing results and poor stability in the tungsten series. 1H,183W heteronuclear multiple bond correlation spectroscopy, exploiting a favorable 5J‐coupling between the 183W center and the peripheral protons on the alkylidyne cap, revealed that these ligands upregulate the Lewis acidity
三芳基硅烷醇盐是用于炔复分解的钼亚烷基催化剂的优先辅助配体,但在钨系列中导致令人失望的结果和较差的稳定性。1 H, 183 W 异核多重键相关光谱,利用183 W 中心与烷叉帽上的外围质子之间有利的5 J耦合,揭示了这些配体将路易斯酸度上调到一定程度,使得环丁二烯钨在最初形成[2+2]环加成步骤过度稳定并且催化周转停止。以183 W NMR 位移作为中心原子路易斯酸度的代表,并通过烷叉单元的化学位移张量分析,重新审视了配体设计,并制备了更强的 π 供体全醇盐配体。新的膨胀螯合物具有缓和的路易斯酸度,并且在速率和官能团相容性方面优于带有单齿叔丁氧基配体的经典Schrock催化剂。
Silicon-derivates for PET-Imaging
申请人:Bayer Schering Pharma Aktiengesellschaft
公开号:EP1911452A1
公开(公告)日:2008-04-16
This invention relates to silicon-derivated compounds suitable for labelling or already labelled with 18F, methods of preparing such a compound, compositions comprising such compounds, kits comprising such compounds or compositions and uses of such compounds, compositions or kits for diagnostic imaging, preferably positron emission tomography (PET).
This invention relates to silicon-derivated compounds suitable for labelling or already labelled with 18F, methods of preparing such a compound, compositions comprising such compounds, kits comprising such compounds or compositions and uses of such compounds, compositions or kits for diagnostic imaging, preferably positron emission tomography (PET).