613-89-8Relevant articles and documents
Streamlined Routes to Phenacyl Azides and 2,5-Diarylpyrazines Enabled by Deep Eutectic Solvents
Vitale, Paola,Cicco, Luciana,Messa, Francesco,Perna, Filippo Maria,Salomone, Antonio,Capriati, Vito
, p. 5557 - 5562 (2019/08/21)
A Deep Eutectic Solvent like choline chloride/glycerol (1:2 mol mol–1) proved to be an effective, sustainable reaction medium to easily synthesize both phenacyl azides and symmetrical 2,5-diarylpyrazines of interest in pharmacology and in coordination chemistry. Notable features of our report include: (i) nucleophilic substitution reactions of α-halo carbonyl compounds to the corresponding phenacyl azides compatible with the eutectic mixture, (ii) the reduction of phenacyl azides to α-amino carbonyl compounds, which undergo spontaneous dimerisation/cyclisation/aromatisation in the same eutectic mixture to provide valuable pyrazines. Telescoped, one-pot, two-steps stoichiometric/catalytic processes have also been successfully developed to furnish 2,5-diarylpyrazines in up to 95 % yield.
Remote C(sp3)-H Oxygenation of Protonated Aliphatic Amines with Potassium Persulfate
Lee, Melissa,Sanford, Melanie S.
supporting information, p. 572 - 575 (2017/02/10)
This letter describes the development of a method for selective remote C(sp3)-H oxygenation of protonated aliphatic amines using aqueous potassium persulfate. Protonation serves to deactivate the proximal C(sp3)-H bonds of the amine substrates and also renders the amines soluble in the aqueous medium. These reactions proceed under relatively mild conditions (within 2 h at 80 °C with amine as limiting reagent) and do not require a transition metal catalyst. This method is applicable to a variety of types of C(sp3)-H bonds, including 3°, 2°, and benzylic C-H sites in primary, secondary, and tertiary amine substrates.
Copper(II) and cobalt(II) tetrazole-saccharinate complexes as effective catalysts for oxidation of secondary alcohols
Frija, Luís M.T.,Alegria, Elisabete C.B.A.,Sutradhar, Manas,Cristiano, M. Lurdes S.,Ismael, Amin,Kopylovich, Maximilian N.,Pombeiro, Armando J.L.
, p. 283 - 290 (2016/11/04)
Mononuclear Cu(II) and Co(II) complexes comprising 2-methyltetrazole-saccharinate bidentate N,N-chelating ligand have been synthesized for the first time and tested as homogeneous catalysts for oxidation of secondary alcohols in a solvent-free and microwave assisted protocol using aqueous tert-butyl hydroperoxide (TBHP) as oxidant. The developed catalytic system exhibits broad functional group compatibility, allowing efficient and selective conversion of a variety of secondary alcohols, including allylic ones, into the corresponding ketones. With typical 0.2 mol% content of the catalyst and under 20–50 W microwave irradiation, most reactions are complete within 10 min, presenting TONs up to 5.5 × 102 and TOFs up to 1.1 × 104 h?1. No additives and co-oxidants have been used, while TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxyl) acts as inhibitor in most cases. A plausible reaction mechanism involving the new catalytic systems is outlined.
