A new route to triphenylsilane tritium-labeled in the benzene ring was developed: condensation of diphenylsilane with tritium-multilabeled benzene. Triphenylsilane labeled with tritium at the Si-H position was prepared. The labeled silanes can serve as precursors of the triphenylsilylium ion and the corresponding isomeric carbon-centered species; the relative stability of these ions can be judged from the structure of products formed by reactions of these species under identical conditions.
Bestimmung der ionenpaar-basizitǎt von lithium- und kaliumamiden
作者:Hubertus Ahlbrecht、Gunther Scheneider
DOI:10.1016/s0040-4020(01)82054-8
日期:1986.1
Ion pair basicities of lithio and potassio salts of some secondary amines were determined by equilibration with benzyl compounds. With these bases it is possible to span a range of about 19 pK-units from pK = 27 up to 46. The structural dependence of thermodynamic as well as kinetic basicity is discussed. Some new effective amide bases for preparative purposes are recommended. For the first time the
Mechanism of the Deprotonation Reaction of Alkyl Benzyl Ethers with<i>n</i>-Butyllithium
作者:M. Luz Raposo、Fernando Fernández-Nieto、Luis Garcia-Rio、P. Rodríguez-Dafonte、M. Rita Paleo、F. Javier Sardina
DOI:10.1002/chem.201204467
日期:2013.7.15
Kinetic study of the α‐lithiation of benzyl methyl ether (BME) by nBuLi has revealed that increasing the concentration of the organolithium compound does not necessarily increase the reactivity, and this is a consequence of the reactivities of the different nBuLi aggregates present in solution. We propose a dimer‐based mechanism, in which a pre‐complexation step is a key process for substrates bearing
Yield and selectivity enhancement by trimethylsilyl chloride in the conjugate addition of stabilized organolithiums
作者:Hong Liu、Theodore Cohen
DOI:10.1016/0040-4039(95)01919-9
日期:1995.12
The yield and selectivity in the conjugateaddition of some stabilizedorganolithiums to α,β-unsaturated carbonyl compounds, especially easily polymerized ones, are increased in the presence of trimethylsilylchloride, alone or in combination with hexamethylphosphoric triamide. E-silyl enol ethers bearing the versatile phenylthio group are obtained prior to hydrolysis. Some synthetic uses are demonstrated
Single-electrontransferreactions between tritylanion and 1-acyl-2,2-dimethylaziridines provide, among other products, the methallyl amides 7 and the triphenylmethanes 8 carrying an amidoethyl chain attached with the tertiary carbon ortho to the triphenylmethane.
BF3-etherate promoted alkylation of aziridines with organocopper reagents: a new synthesis of amines
作者:Michael J. Eis、Bruce Ganem
DOI:10.1016/s0040-4039(00)98420-x
日期:1985.1
Boron trifluoride etherate promotes nucleophilic ring opening of a variety of substituted aziridines by diorganocopperlithium reagents leading to both primary and secondary amines.