Interaction of aryltrimethylstannanes with cyanogen chloride and bromide. A route to aryl cyanides
作者:E.H. Bartlett、C. Eaborn、D.R.M. Walton
DOI:10.1016/s0022-328x(00)88327-8
日期:1972.12
Phenyltrimethylstannane has been found to react with cyanogenchloride in methylene chloride in the presence of aluminium chloride to give benzonitrile in 60% yield; o-, m-, and p-tolyltrimethylstannane similarly give o-, m-, and p-tolunitrile, respectively. With cyanogenbromide the aryl bromides are formed.
Through-space interactions between parallel-offset arenes at the van der Waals distance: 1,8-diarylbiphenylene syntheses, structure and QM computations
作者:Franco Cozzi、Rita Annunziata、Maurizio Benaglia、Kim K. Baldridge、Gerardo Aguirre、Jesús Estrada、Yongsak Sritana-Anant、Jay S. Siegel
DOI:10.1039/b800031j
日期:——
A model for studying polar–π interactions between arenes spaced at van der Waals distances is developed on the basis of peri-diarylbiphenylenes. A set of 1,8-diarylbiphenylenes is synthesized comprising two Hammett series, one with reference to mesityl ring interactions and the other with reference to pentafluorophenyl ring interactions. X-Ray crystal structures of several derivatives are determined. Barriers to rotation of the probe aryl ring are derived from dynamic NMR data and show a trend for the mesityl reference series (ΔG≠vs. σ°). The model is also used as a test for comparison of modern density functional methods, including B3LYP, M06-2X and BMK functionals; dispersive effects are seen to be an important factor in the proper theoretical treatment of arene interactions.
Synthesis of platinum(II) alkyl and aryl complexes from K2[PtCl4] and tetraorganotin compounds in dimethyl sulphoxide
作者:Colin Eaborn、Kalipada Kundu、Alan Pidcock
DOI:10.1039/dt9810000933
日期:——
Complexes cis-[PtR2(dmso)2] and cis-[PtRCl(dmso)2](dmso = dimethyl sulphoxide) are readily obtained from K2[PtCl4] and SnMe3R (R = aryl or Me) in dmso at 70–90 °C. Hydrogen-1 n.m.r. spectra show that the dmso ligands are bound through sulphur in solution and that the dmso ligand trans to R in cis-[PtRCl(dmso)2] undergoes dissociation and exchange at ambient temperature. With anionic reagents X–(X =
Ultrasound-assisted synthesis of unsymmetrical biaryls by Stille cross-coupling reactions
作者:Claudia E. Domini、Gustavo F. Silbestri、Beatriz Fernández Band、Alicia B. Chopa
DOI:10.1016/j.ultsonch.2011.08.013
日期:2012.5
We describe herein an efficient method for the synthesis of unsymmetrically-substituted biphenyls using a sonochemical variation of the Stille coupling, whose results have also been compared with the conventional silent reaction. Ultrasound significantly enhances this useful organometallic transformation affording products in higher yields and in shorter reaction times than non-irradiated reactions
Aromatic reactivity. Part XXXV. Alkali cleavage of aryltrimethylstannanes: an unusual electrophilic aromatic substitution
作者:C. Eaborn、H. L. Hornfeld、D. R. M. Walton
DOI:10.1039/j29670001036
日期:——
We have measured spectrophotometrically the rates of cleavage by aqueous methanolic alkali of the aryl–tin bonds in a series of X·C6H4·SnMe3 compounds. In this reaction, the rate-determining step of which probably involves separation of the carbanion X·C6H4–, the effects of meta substituents are in accord with the Hammett σ constants (σ= 2·18), but the effects of para substituents show an abnormal
我们通过分光光度法测量了一系列X·C 6 H 4 ·SnMe 3化合物中芳基-锡键的甲醇碱水溶液的裂解速率。在该反应中,确定速率的步骤可能涉及分离碳负离子X·C 6 H 4 –,间位取代基的作用与Hammettσ常数(σ= 2·18)一致,但对位取代基显示异常图案。例如,不仅通过诸如p -CF 3和p -Cl的吸电子基团,而且通过诸如p -OMe和p -NMe 2。对于对位取代基时,效果大致与它们线σ 1周的常数。