Transmission of electronic effects via a SiMe2 spacer in 4-mono- and 4,4′-disubstituted diphenyldimethylsilanes: 29Si and 13C NMR spectroscopy and PM3 semi-empirical calculations
作者:Cornelis A. van Walree、Xavier Y. Lauteslager、Andreas M.A. van Wageningen、Jan W. Zwikker、Leonardus W. Jenneskens
DOI:10.1016/0022-328x(95)05473-3
日期:1995.6
13C NMR studies were performed on series of 4-substituted phenyltrimethylsilanes and 4-substituted and 4,4′-disubstituted diphenyldimethylsilanes. Within each series linear relationships are found between the chemicalshifts and (a) the Hammett substituentconstants σp and (b) the PM3-calculated total atomic charges. It is inferred that the SiMe2 σ-type spacer weakly mediates substituenteffects in
对一系列4-取代的苯基三甲基硅烷和4-取代的和4,4'-二取代的二苯基二甲基硅烷进行了约29 Si和13 C NMR研究。在每个系列的线性关系被化学位移和(a)的哈米特取代基常数之间发现σ p和(b)的PM3计算总原子电荷。据推断,所述森达2 σ型分隔弱介导通过键偏振机构处于基态的取代基的影响。与4-取代的和4,4'-二取代的二苯基甲烷的可用数据进行的比较表明,SiMe 2基团比CH 2基团更好地传递电子效应。
Synthesis of Biaryls by Intramolecular Radical Aryl Migration from Silicon to Carbon
作者:Armido Studer、Martin Bossart、Tomaso Vasella
DOI:10.1021/ol005661f
日期:2000.4.1
A new method for the preparation of biaryls via intramolecular 1,5 aryl migration reaction from silicon in silyl ethers to arylradicals is presented. Various readily available diphenylsilyl ethers can be used as substrates in this reaction. Functionalized aryl groups can also be transferred. The analogous 1,4 aryl migration reaction is less efficient.
Kinetische Untersuchungen �ber die Silicium?Aryl-Spaltung mit Bromwasserstoff
作者:Edwin Hengge、Hugo Eberhardt
DOI:10.1007/bf00903746
日期:——
Modular diphosphine ligands based on bisphenol A backbones
作者:Jarl Ivar van der Vlugt、Josep M. Bonet、Allison M. Mills、Anthony L. Spek、Dieter Vogt
DOI:10.1016/s0040-4039(03)00948-1
日期:2003.6
A straightforward two-step synthesis is used to obtain new phosphorus-containing ligands based on readily available bisphenol A type backbones. Five diphosphine ligands have been prepared in good yields. An X-ray crystallographic study is presented for ligand 5. Preliminary results on rhodium-catalyzed hydroformylation exemplify the use of these ligands for homogeneous catalysis. (C) 2003 Elsevier Science Ltd. All rights reserved.