A broad overview of the achievements and emerging areas in the field of Green Chemistry.

We provide a critical review of green processes enabling the fractionation and/or depolymerization of lignin towards value-added products.

The oxidation of phenols is the subject of extensive investigation, but there are few catalytic aerobic examples that are chemo- and regioselective. Here we describe conditions for the ortho-oxygenation or oxidative coupling of phenols under copper (Cu)-catalyzed aerobic conditions that give rise to ortho-quinones, biphenols or benzoxepines. We demonstrate that each product class can be accessed selectively by the appropriate choice of Cu(I) salt, amine ligand, desiccant and reaction temperature. In addition, we evaluate the effects of substituents on the phenol and demonstrate their influence on selectivity between ortho-oxygenation and oxidative coupling pathways. These results create an important precedent of catalyst control in the catalytic aerobic oxidation of phenols and set the stage for future development of catalytic systems and mechanistic investigations.

A sustainable bio-based future necessitates the utilization of all components of biomass including lignin, which is the second most abundant biopolymer and a source of renewable aromatics. While its use...

A copper-doped porous metal oxide catalyst in combination with hydrogen shows selective and quantitative hydrogenolysis of benzyl ketones and aldehydes, and hydrogenation of alkenes.

A N2-H2 glow discharge for metallic surface nitriding at low pressure (1-3 Torr) and low current density (1-6 mA cm-2) has been studied by emission spectroscopy. The N2, N2+, N, N+, H, NH and metal atom excited states have been detected. The rotational temperature of N2+(B2 Sigma u+) states in the negative glow near the cathode surface has been found to be in quasi-equilibrium with the cathode temperature. By using argon as a gas impurity (2%), it has been established that the N2(C3 Pi u) states are excited in the negative glow near the cathode fall by direct electron impact. The NH radicals appear to issue near the cathode surface as do metal atoms.

No abstract

Muconic acid and muconolactones are gaining high interest as platform molecules for the synthesis of a variety of compounds, especially in the domain of materials. Despite several technologies have been...