A fast and operationally simple method for the aerobic homocoupling of arylboronic acids is described. The process is catalyzed by Pd(II) complexes supported on the metal‐organic framework MIL‐88B‐NH2(Cr). The benefits of this approach include the use of a benign oxidant/solvent mixture at room temperature with catalytic amounts of base, easy recovery of the catalyst, and easy isolation of the products
Cobalt-Catalyzed Defluorosilylation of Aryl Fluorides via Grignard Reagent Formation
作者:Soobin Lim、Hyungdo Cho、Jongheon Jeong、Minjae Jang、Hyunseok Kim、Seung Hwan Cho、Eunsung Lee
DOI:10.1021/acs.orglett.0c02752
日期:2020.9.18
cheap electrophilic silicon source with magnesium. This method is compatible with various silicon sources and can be operated under aerobic conditions. Mechanistic studies support the in situ formation of a Grignard reagent, which is captured by the electrophilic silicon source.
Homocoupling of Arylboronic Acids with a Catalyst System Consisting of a Palladium(II) N-Heterocyclic Carbene Complex and <i>p</i>-Benzoquinone
作者:Yoshihiko Yamamoto
DOI:10.1055/s-2007-984531
日期:2007.7
In the presence of 1-3 mol% SIPr-ligated Pd(OAc)2 and 0.6 equivalent of p-benzoquinone, various arylboronic acids underwent homocoupling in MeOH at ambient temperature to produce symmetrical biaryls in 38-96% yields.
Organosilicon compounds. Part XLIII. Preparation of aryl sulphones by desilylation or destannylation
作者:S. N. Bhattacharya、C. Eaborn、D. R. M. Walton
DOI:10.1039/j39690001367
日期:——
chloride has been used to give the diaryl sulphone X·C6H4SO2·C6H4·Y in moderately good yield; examples are the sulphones with X and Y as follows: H, H (62%); p-Me, H (62); H, p-Me (61); p-OMe, H (65); p-F, H (58); H, p-Me3Si (57); H, p-Ph (53). The methanesulphonyl chloride–aluminium chloride complex has been used similarly to give the aryl methyl sulphones p-X·C6H4·SO2Me, with X = H (58%), F (58),
用预先形成的芳磺酰氯-氯化铝(Y·C 6 H 4 ·SO 2 Cl,AlCl 3)络合物在二氯甲烷中处理芳基三甲基锡烷(X·C 6 H 4 ·SnMe 3)已得到二芳基砜X·C 6 H 4 SO 2 ·C 6 H 4 ·Y的收率中等;实例为具有X和Y的砜,如下所示:H,H(62%); p -Me,H(62);m -H,62。H,p- Me(61);H,p- Me(61)。p- OMe,H(65);m / z。p -F,H(58);H,p -Me 3硅(57); H,p- Ph(53)。类似地,使用甲磺酰氯-氯化铝络合物得到芳基甲基砜p -X·C 6 H 4 ·SO 2 Me,其中X = H(58%),F(58)或Me(55),还有异丁烯基甲基砜(31%)。
Highly Stable, Low Gas Crossover, Proton-Conducting Phenylated Polyphenylenes
作者:Michael Adamski、Thomas J. G. Skalski、Benjamin Britton、Timothy J. Peckham、Lukas Metzler、Steven Holdcroft
DOI:10.1002/anie.201703916
日期:2017.7.24
membrane‐electrode assemblies containing each ionomermembrane yield high in situ proton conductivity and peak power densities that are greater than obtained using Nafion reference membranes. In situ chemical stability accelerated stress tests reveal that this class of the polyaromatic membranes allow significantly lower gas crossover and lower rates of degradation than Nafion benchmark systems. These results point