One-pot dialkylation of allylphenylsulfide induced by aminoalkoxides-activated NaNH2. Application to the synthesis of unsymmetrical ketones
作者:Sabine Choppin、Philippe Gros、Yves Fort
DOI:10.1016/s0040-4020(99)00481-0
日期:1999.7
aminoalkoxides, leading to new superbases, induced an efficient one-pot dialkylation of allylphenylsulfide. The regioselectivity of the reaction (α,α′ vs α,γ) was found as strongly dependent on the nature of the alkyl halide. As an application, α,γ dialkylated products were efficiently converted into the corresponding unsymmetrical ketones.
Abstract The radical reaction of benzenethiol with alkynes 1a-o carried out at 154 °C affords a mixture of thiol/alkyne adduct 3 and benzothiophene 5, deriving from vinyl radical intermediates 2 through hydrogen abstraction and 5-(π-endo)orthocyclization onto the adjacent thiophenyl ring, respectively. This latter reaction occurs through the reversible formation of cyclohexadienyl radical intermediates
One electron transfer reaction of phenyl vinyl sulfides with dioxygen. The fate of the intermediate vinyl sulfide radical cations.
作者:Luisa Benati、Pier Carlo Montevecchi、Daniele Nanni、Piero Spagnolo
DOI:10.1016/s0040-4039(00)73645-8
日期:1993.5
Mild reaction of pheyl vinyl sulfides with dioxygen can lead to the eventual formation of rearranged vinyl sulfides and/or carbonyl-containing sulfide products, which are believed to result from decomposition of initially-formed vinyl sulfideradical cations. Supporting evidence is provided by the comparable findings obtained from the one electron oxidation of one vinyl sulfide by cerium (IV) ammonium
CAN- and DDQ-Promoted Oxidation of Alkenyl Sulfides
作者:Laura Capella、Pier Carlo Montevecchi、Daniele Nanni
DOI:10.1021/jo00103a033
日期:1994.12
Vinyl sulfides 1 react with CAN in acetonitrile at room temperature to give radical cations 2A in equilibrium with the thiiranyl radical cations 2B. The reaction products arise from nucleophilic attack of the nitrate counterion at either the sulfur atom of 2A or the trivalent carbon of 2B. The last reaction can proceed through 1,2-shift or displacement of the sulfide moiety. When alpha-methylenic protons are present in 2B, deprotonation occurs, leading to allyl radicals and, ultimately, to isomeric allyl alcohols. Reactions of 1 with DDQ in acetonitrile afford charge-transfer complexes and then zwitterionic electron-transfer (ET) complexes which can evolve rapidly through intramolecular proton transfer when trans methylenic protons are present. The resulting sulfur-oxygen sigma-complexes are responsible for the reaction products mainly through either gamma-elimination of DDQH(2) or nucleophilic attack at the delta-vinylic carbon followed by displacement of DDQH(-).