an alkyl- lithium to 1-phenylthio-1-trimethylsilylethene (7), and transmetallation of a tributylstannyl moiety. The formation of an alkyl-lithium by reaction of lithium naphthalenide with a phenyl sulphide provided an additional route to (2) from bis(phenylthio)acetals (8). An alternative path to the α-phenylthiosilanes (2) was to reduce the corresponding α-phenylsulphonylsilane (15); these, in turn
Facile preparation and reactivity of bifunctional ionic liquid-supported hypervalent iodine reagent: a convenient recyclable reagent for catalytic oxidation
作者:Chenjie Zhu、Akira Yoshimura、Yunyang Wei、Victor N. Nemykin、Viktor V. Zhdankin
DOI:10.1016/j.tetlet.2012.01.053
日期:2012.3
efficient, and recyclable bifunctional catalysts bearing ionic liquid supported (2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) and iodoarene moieties were developed and used for environmentally benign catalytic oxidation of alcohols. The reactions using peracetic acid as a green and practical co-oxidant afforded the corresponding carbonyl compounds in high yields under mild conditions and convenient work-up
Oxidative Dehomologation of Aldehydes with Oxygen as a Terminal Oxidant
作者:Sergei A. Shipilovskikh、Aleksandr E. Rubtsov、Andrei V. Malkov
DOI:10.1021/acs.orglett.7b03512
日期:2017.12.15
A mild, efficient protocol for oxidative cleavage of C–C bonds in aldehydes has been developed that employs alkalimetalhydrides as reagents and oxygen from air as a terminal oxidant. The method is applicable to a broad substrate range.
Cycloadditions of 1-aza-2-azoniaallene ions to alkenes
作者:Wolfgang G. Wirschun、Yaseen A. Al-Soud、Konstanze A. Nusser、Olli Orama、Gerd-Michael Maier、Johannes C. Jochims
DOI:10.1039/b006525k
日期:——
1-Aza-2-azoniaallene salts 3 react with ethene, and mono- to trisubstituted electron-rich alkenes under mild conditions to afford 4,5-dihydro-3H-pyrazolium salts 4. These cycloadditions proceed with complete Markovnikov regioselectivity and retention of the configuration of the alkene. Reactions of salts 3 with norbornene afford cycloadducts without rearrangement of the norbornane moiety. According to these observations, reactions of heteroallenes 3 with alkenes are mechanistically concerted ‘reverse electron-demand 1,3-dipolar cycloadditions’. In solution 4,5-dihydro-3H-pyrazolium salts 4 with a hydrogen atom in the 5-position tautomerize to 4,5-dihydro-1H-pyrazolium salts 6. A ‘general Wagner–Meerwein rearrangement’ to the 1H-isomer 5y is observed for compound 4y. The mechanistic proposals are supported by AM1 calculations. For the salt 4r and the twofold cycloadduct 4z X-ray stuctural analyses have been performed.
Herein, we report that nano micelles formulated using two surfactants (anionic sodiumdodecylsulfate (SDS) and anionic sodium tetradecyl sulfate (STS)) in water efficiently catalysed Ce(IV) based oxidation of isomeric pentanols. The observed acceleration of the reaction rate in the presence of micelles has been ascribed to the solubilization of the reactants into micelles as well as the hydrophobic