91970-57-9Relevant academic research and scientific papers
Tandem Acid/Pd-Catalyzed Reductive Rearrangement of Glycol Derivatives
Ciszek, Benjamin,Fleischer, Ivana,Kathe, Prasad,Schmidt, Tanno A.
, p. 3641 - 3646 (2020/03/25)
Herein, we describe the acid/Pd-tandem-catalyzed transformation of glycol derivatives into terminal formic esters. Mechanistic investigations show that the substrate undergoes rearrangement to an aldehyde under [1,2] hydrogen migration and cleavage of an oxygen-based leaving group. The leaving group is trapped as its formic ester, and the aldehyde is reduced and subsequently esterified to a formate. Whereas the rearrangement to the aldehyde is catalyzed by sulfonic acids, the reduction step requires a unique catalyst system comprising a PdII or Pd0 precursor in loadings as low as 0.75 mol % and α,α′-bis(di-tert-butylphosphino)-o-xylene as ligand. The reduction step makes use of formic acid as an easy-to-handle transfer reductant. The substrate scope of the transformation encompasses both aromatic and aliphatic substrates and a variety of leaving groups.
ONE ELECTRON OXIDATION OF BENZYL AND 2-PHENYLETHYL PHENYL ETHERS. THE FATE OF THE INTERMEDIATE RADICAL CATIONS
Baciocchi, Enrico,Piermattei, Alessandro,Rol, Cesare,Ruzziconi, Renzo,Sebastiani, Giovanni Vittorio
, p. 7049 - 7062 (2007/10/02)
The one electron oxidations of benzyl phenyl ether (1), 2-phenylethyl phenyl ether (2) and 2-(4-methoxyphenyl)ethyl phenyl ether (3) promoted (a) by cerium(IV) ammonium nitrate (CAN) in AcOH, (b) electrochemically in AcOH-MeCN/AcOK and (c) photochemically in MeCN, in the presence of 9,10-dicyanoanthracene (DCA), have been investigated.With 1 benzaldehyde forms, under all the reaction conditions, accompanied by products of acetoxylation at the phenoxy ring (conditions a and b) or by phenyl benzoate (condition c).The CAN-promoted and the electochemical oxidation of 2 exclusively lead to substitution at the phenoxy ring, whereas only side-chain attack at the benzylic carbon occurs in all of the reactions of 3, with formation of 4-methoxybenzaldehyde and products of side-chain oxidation.Phenyl 4-methoxybenzoate is also formed (conditions b and c).However, when the electrochemical oxidation is carried out in the absence of AcOK, only a product of intermolecular ring closure forms.These results allow one to draw some interesting conclusion on the competition between the various reaction pathways available to the cation radicals which are the first formed reaction intermediates in these one electron processes.
