21905-69-1Relevant articles and documents
Photodecarboxylation of xanthone acetic acids: C-C bond heterolysis from the singlet excited state
Blake, Jessie A.,Gagnon, Eric,Lukeman, Matthew,Scaiano
, p. 1057 - 1060 (2006)
Irradiation of 2- and 4-xanthone acetic acid in aqueous buffer (pH 7.4) leads to efficient (Φ = 0.67 and 0.64, respectively) photodecarboxylation to give the corresponding methyl products, consistent with an intermediate benzylic carbanion. Fluorescence a
The use of ultrasound in the synthesis of 2-carboxy substituted diphenylethers using water as solvent
Pellon Comdom, Rolando F.,Docampo Palacios, Maite L.
, p. 921 - 926 (2003)
An improved synthesis of 2-carboxy substituted diphenylethers using water as solvent can be achieved by ultrasound irradiation. A number of diphenylethers was prepared in good yields in a very short reaction time.
Electrochemical Reductive Smiles Rearrangement for C-N Bond Formation
Chang, Xihao,Zhang, Qinglin,Guo, Chang
supporting information, p. 10 - 13 (2019/01/04)
A conceptually new and synthetically valuable radical Smiles rearrangement reaction is reported under undivided electrolytic conditions. This protocol employs an entirely new strategy for the electrochemical radical Smiles rearrangement. Remarkably, an amidyl radical generated from the cleavage of the N-O bond under reductive electrolytic conditions plays a crucial role in this transformation. Various hydroxylamine derivatives bearing different substituents are suitable in this electrochemical transformation, furnishing the corresponding amides in up to 86% yield.
A photoredox-neutral Smiles rearrangement of 2-aryloxybenzoic acids
Gonzalez-Gomez, Jose C.,Ramirez, Nieves P.,Lana-Villarreal, Teresa,Bonete, Pedro
supporting information, p. 9680 - 9684 (2017/11/30)
We report on the use of visible light photoredox catalysis for the radical Smiles rearrangement of 2-aryloxybenzoic acids to obtain aryl salicylates. The method is free of noble metals and operationally simple and the reaction can be run under mild batch or flow conditions. Being a redox neutral process, no stoichiometric oxidants or reductants are needed.
Efficient Aryl Migration from an Aryl Ether to a Carboxylic Acid Group To Form an Ester by Visible-Light Photoredox Catalysis
Wang, Shao-Feng,Cao, Xiao-Ping,Li, Yang
supporting information, p. 13809 - 13813 (2017/10/24)
We have developed a highly efficient aryl migration from an aryl ether to a carboxylic acid group through retro-Smiles rearrangement by visible-light photoredox catalysis at ambient temperature. Transition metals and a stoichiometric oxidant and base are avoided in the transformation. Inspired by the high efficiency of this transformation and the fundamental importance of C?O bond cleavage, we developed a novel approach to the C?O cleavage of a biaryl ether to form two phenolic compounds, as demonstrated by a one-pot, two-step gram-scale reaction under mild conditions. The aryl migration exhibits broad scope and can be applied to the synthesis of pharmaceutical compounds, such as guacetisal. Primary mechanistic studies indicate that the catalytic cycle occurs by a reductive quenching pathway.
Carboxyl radical-assisted 1,5-aryl migration through Smiles rearrangement
Hossian, Asik,Jana, Ranjan
, p. 9768 - 9779 (2016/10/31)
We report herein, a silver(i)-catalyzed Smiles rearrangement of 2-aryloxy- or 2-(arylthio)benzoic acids to provide aryl-2-hydroxybenzoate or aryl-2-mercaptobenzoate dimer, respectively, through 1,5-aryl migration from oxygen or sulfur to carboxylate oxygen. Mechanistically, the aryl ether moiety undergoes an intramolecular ipso attack by the carboxyl radical followed by a C-O or C-S bond cleavage. Aryl-2-mercaptobenzoates undergo oxidative dimerization through a thiol moiety in situ.
Synthesis and evaluation of pharmacological properties of some new xanthone derivatives with piperazine moiety
Waszkielewicz,Gunia,Szkaradek,Pytka,Siwek,Sata?a,Bojarski,Szneler,Marona
supporting information, p. 4419 - 4423 (2013/07/26)
A series of new xanthone derivatives with piperazine moiety [1-7] was synthesized and evaluated for their pharmacological properties. They were subject to binding assays for α1 and β1 adrenergic as well as 5-HT1A, 5-HTsub
Microwave-assisted synthesis of 2-phenoxybenzoic acids
Pellon, Rolando F.,Martin, Ana,Mesa, Miriam,Docampo, Maite L.,Gomez, Victoria
, p. 527 - 529 (2007/10/03)
Substituted 2-phenoxybenzoic acid derivatives were synthesised in high yield and in short reaction times using the Ullmann condensation of 2-chlorobenzoic acid with phenol derivatives under microwave irradiation in dry media.
Substituted xanthones as antimycobacterial agents*, part 1: Synthesis and assignment of 1H/13C NMR chemical shifts
Pickert, Martina,Frahm, August Wilhelm
, p. 177 - 192 (2007/10/03)
A series of substituted xanthones was synthesized in order to prove the hypothesis that electron-withdrawing substituents enhance the antimycobacterial activity of these compounds, which is described by means of a QSAR equation with 13C NMR che
