A two-step straightforward method for the preparation of ortho-alkylated vinylarenes from readily available benzoic acids is described. The synthetic route involves the dearomatization of benzoic acids by Birchreduction providing alkylated cyclohexa-2,5-dienyl-1-carboxylic acids. The diene subsequently undergoes a decarboxylative C–H olefination followed by rearomatization to deliver ortho-alkylated
Functionalized Allyl Aryl Ether Synthesis from Benzoic Acids Using a Dearomatization and Decarboxylative Allylation Approach
作者:Cheng-En Hsieh、Yu-Min Jiang、Chih-Ming Chou
DOI:10.1021/acs.joc.8b02487
日期:2019.1.18
toward the preparation of substituted allyl arylethers from benzoic acids via a dearomatization and decarboxylative allylation (DcA) reaction is presented. The benzoic acids undergo a dearomatization to give alkylated 2,5-cyclohexadienyl ketoesters which are subjected to a palladium-catalyzed DcA reaction, providing a variety of functionalized allyl arylethers. In addition, the combination of a resonance
Regioselective Threefold Aromatic Substitution of Benzoic Acid Derivatives by Dearomatization, Regioselective Functionalization, and Rearomatization
作者:Eva Koch、Armido Studer
DOI:10.1002/anie.201300259
日期:2013.4.26
Ipso, meta, and para: Benzoic acid derivatives can be highly regioselectively substituted at the ipso, meta, and para positions. The reaction sequence comprises an alkylative Birchreduction, a 4‐alkylation, a palladium‐catalyzed γ‐arylation, and an oxidative rearomatization (see scheme). All the reactions are robust and experimentally easy to conduct.
Aromatisation of some cyclohexadienes through methoxycarbonyl migration or alkyl elimination
作者:R. Morrin Acheson、Rowena F. Flowerday
DOI:10.1039/p19740002339
日期:——
Treatment of methyl 1,2-dimethyl- or 1-ethyl-2-methyl-cyclohexa-2,5-diene-1-carboxylate with triphenylmethyl tetrafluoroborate caused aromatisation to the methyl 2,3-dialkylbenzoates by migration of the methoxycarbonyl group. The corresponding 1-isopropyl- and 1-benzyl-cyclohexadienes gave methyl o-toluate under the same conditions.
The capability of platinum, palladium and ruthenium sulfophthalocyanines (PtPcS, PdPcS and RuPcS) to act as singletoxygen [1O2(1Δg)] photosensitizers in enereactions in aqueous medium has been investigated by combining time-resolved and steady-state techniques. Laser flash photolysis experiments with nanosecond time resolution revealed the population of the lowest excited triplet state in the case