18028-09-6Relevant academic research and scientific papers
Design, Synthesis, and Implementation of Sodium Silylsilanolates as Silyl Transfer Reagents
Yamagishi, Hiroki,Saito, Hayate,Shimokawa, Jun,Yorimitsu, Hideki
, p. 10095 - 10103 (2021/08/18)
There is an increasing demand for facile delivery of silyl groups onto organic bioactive molecules. One of the common methods of silylation via a transition-metal-catalyzed coupling reaction employs hydrosilane, disilane, and silylborane as major silicon sources. However, the labile nature of the reagents or harsh reaction conditions sometimes render them inadequate for the purpose. Thus, a more versatile alternative source of silyl groups has been desired. We hereby report a design, synthesis, and implementation of storable sodium silylsilanolates that can be used for the silylation of aryl halides and pseudohalides in the presence of a palladium catalyst. The developed method allows a late-stage functionalization of polyfunctionalized compounds with a variety of silyl groups. Mechanistic studies indicate that (1) a nucleophilic silanolate attacks a palladium center to afford a silylsilanolate-coordinated arylpalladium intermediate and (2) a polymeric cluster of silanolate species assists in the intramolecular migration of silyl groups, which would promote an efficient transmetalation.
A flow microreactor system enables organolithium reactions without protecting alkoxycarbonyl groups
Nagaki, Aiichiro,Kim, Heejin,Moriwaki, Yuya,Matsuo, Chika,Yoshida, Jun-Ichi
supporting information; experimental part, p. 11167 - 11177 (2010/11/04)
A flow microreactor system consisting of micromixers and microtube reactors provides an effective tool for the generation and reactions of aryllithiums bearing an alkoxycarbonyl group at para-, meta-, and ortho-positions. Alkyl p- and m-lithiobenzoates were generated by the I/Li exchange reaction with PhLi. The Br/Li exchange reactions with sBuLi were unsuccessful. Subsequent reactions of the resulting aryllithiums with electrophiles gave the desired products in good yields. On the other hand, alkyl o-lithiobenzoates were successfully generated by the Br/ Li exchange reaction with sBuLi. Subsequent reactions with electrophiles gave the desired products in good yields.
Rhodium-catalyzed silylation and intramolecular arylation of nitriles via the silicon-assisted cleavage of carbon-cyano bonds
Tobisu, Mamoru,Kita, Yusuke,Ano, Yusuke,Chatani, Naoto
supporting information; experimental part, p. 15982 - 15989 (2009/05/16)
A rhodium-catalyzed silylation reaction of carbon - cyano bonds using disilane has been developed. Under these catalytic conditions, carbon-cyano bonds in aryl, alkenyl, allyl, and benzyl cyanides bearing a variety of functional groups can be silylated. The observation of an enamine side product in the silylation of benzyl cyanides and related stoichiometric studies indicate that the carbon-cyano bond cleavage proceeds through the deinsertion of silyl isocyanide from η2-iminoacyl complex B. Knowledge gained from these studies has led to the development of a new intramolecular biaryl coupling reaction in which aryl cyanides and aryl chlorides are cross-coupled.
Diphenylphosphinophenolate: A ligand for the palladium-catalysed silylation of aryl halides activating simultaneously both palladium and silicon
Shirakawa,Kurahashi,Yoshida,Hiyama
, p. 1895 - 1896 (2007/10/03)
Diphenylphosphinophenolate was found to be an effective ligand for the palladium-catalysed silylation of aryl halides, activating not only palladium but also silicon of a disilane, where aryl bromides and iodides having such substituents as methyl, methoxy, amino, ethoxycarbonyl, trifluoromethyl, formyl or phenyl are applicable to the reaction with hexamethyldisilane to give the corresponding trimethylsilylarenes.
A mild and efficient protocol for the catalytic silylation of aryl bromides
Goossen,Ferwanah
, p. 1801 - 1803 (2007/10/03)
New catalyst systems were developed which facilitate palladium-catalyzed silylation of various functionalized aryl and heteroaryl bromides with hexamethyldisilane under unprecedented mild conditions. The use of two different sets of ligands and bases for electron-rich and electron-poor substrates, respectively, is crucial for achieving excellent product selectivities at 100 °C and atmospheric pressure. For electron-rich substrates, diphenyl-2'-pyridylphosphine in combination with K2CO3 gives the best results, whereas for electron-poor substrates, 2-(di-t-butylphosphino)biphenyl/KF is preferred. Even base-sensitive arylsilanes, which are inaccessible by the traditional routes via organolithium species or Grignard reagents, can be prepared in a single step and high yields.
Substituent Effect on the Electrochemical Oxidation of Trityl Anions. 2. Effect of an Electron-Withdrawing Group
Bank, Shelton,Ehrlich, Clifford L.,Mazur, Mark,Zubieta, Jon A.
, p. 1243 - 1247 (2007/10/02)
The reversible one-electron oxidations of triarylmethyl anions and the irreversible second oxidative processes were examined for a series of sequentially substituted p-trimethylsilyl anions.The cycle voltammograms of the lithium salts prepared in dimethox
