Damage of polyesters by the atmospheric free radical oxidant NO₃^•: a product study involving model systems

• Catrin Goeschen and
• Uta Wille

Beilstein J. Org. Chem. 2013, 9, 1907–1916, doi:10.3762/bjoc.9.225

• well as products of these reactions are potentially capable of promoting further degradation processes in polyesters under environmental conditions. Keywords: environmental oxidants; free radicals; nitrate radicals; polyester degradation; product studies; reaction mechanisms; Introduction Polymers

• the strongest free-radical oxidants known [E(NO3•/NO3−) = 2.3–2.5 V vs NHE] [9], and recent product studies by us revealed that NO3• readily damages aromatic amino acids and pyrimidine nucleosides through an oxidative pathway [10][11][12][13]. Thus, the ease by which model compounds of biologically

Interplay of ortho- with spiro-cyclisation during iminyl radical closures onto arenes and heteroarenes

• Roy T. McBurney and
• John C. Walton

Beilstein J. Org. Chem. 2013, 9, 1083–1092, doi:10.3762/bjoc.9.120

• alkoxycarbonyloxyl radicals. An interesting feature was that addition was selective for meta to the t-Bu group; as was previously observed with the σ-radicals. Product studies with bridgehead radicals at higher temperatures (80 °C) had also revealed this preference for meta-attack [40][41]. The selectivity for meta

New reactive intermediates in organic chemistry

• Götz Bucher

Beilstein J. Org. Chem. 2013, 9, 613–614, doi:10.3762/bjoc.9.67

• , product studies can even yield accurate values for the kinetics of intermolecular quenching reactions of reactive intermediates. More recent techniques to characterise reactive intermediates include matrix isolation spectroscopy, where a reactive intermediate is generated in a cryogenic noble-gas matrix

• Engineering and Physical Sciences Research Council of the UK (EPSRC) funded two Centres for Physical Organic Chemistry, one in Cardiff, and one in Glasgow, and launched two calls for research proposals in POC. Research into reactive intermediates has historically been part of the work involved in product

• studies. In order to characterise a reactive intermediate, it had to be trapped. Thus, in order to characterise a carbene, for example, one would intercept it with an alkene and isolate the resulting cyclopropane. Using internal quenchers (molecular clocks) providing well-defined competing reactions