The fate of most lignin linkages, other than the β-O-4, under selective oxidation conditions is largely unknown. In this work we use advanced β-5 lignin model compounds to identify the fate of phenylcoumaran units in a softwood lignin during oxidation with DDQ. By using model compounds combined with detailed characterisation of the oxidised lignin polymer using HSQC and HMBC NMR we show that ph...

Condensation of 16-silatripyrrane with pentafluorobenzaldehyde under catalytic conditions followed by DDQ oxidation leads to 31,34-disilahexaphyrinoid--a four times reduced derivative of 31,34-disilahexaphyrin which contains two built-in silole units flanked by four tetrahedrally hybridized meso carbons. In the preferred folded macrocyclic conformation the silole rings remain perpendicular to e...

Hexakis(pentafluorophenyl)-substituted meso-meso-linked Zn(II)-diporphyrin (9), which was prepared by the acid-catalyzed cross-condensation of 1,1,2,2-tetrapyrroethane (5) with dipyrromethane dicarbinol (6), was converted into meso-meso,β-β,β-β triply linked Zn(II)-diporphyrin 3 by oxidation with 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) and Sc(OTf)(3). Beside the red-shifted absorption spectr...

Investigation of charge-transfer (CT) complexes of drugs has been recognized as an important phenomenon in understanding of the drug-receptor binding mechanism. Structural, thermal, morphological and biological behavior of CT complexes formed between drug quinidine (Qui) as a donor and quinol (QL), picric acid (PA) or dichlorodicyanobenzoquinone (DDQ) as acceptors were reported. The newly synth...

This report describes the development of a language based on VHDL intended to simplify the use of IDDQ instrumentation in production testing. This language called 'Monitor Description Fonnat' or MDF, is part of the development by QTAG (Quality Test Action Group) of an infrastructure for quiescent current testing. The MDF can be used with commercial supported QTAG monitors (lDDQ measurement equi...

Pyranoxanthones 6-8 were obtained by dehydrogenation of the respective dihydropyranoxanthones 3-5 with DDQ in dry dioxane. Two prenylated xanthones 10,11 were obtained from the reaction of 1-hydroxyxanthone (9) with prenyl bromide in alkaline medium, or by condensation of xanthone 9 with isoprene in the presence of orthophosphoric acid. The structural elucidation of the two new compounds 6,11, ...

Several bioactive natural p-hydroxyphenylalkyl β-D-glucopyranosides, such as vanillyl β-D-glucopyranoside, salidroside and isoconiferin, and their glycosyl analogues were prepared by a simple reaction sequence. The highly efficient synthetic approach was achieved by utilizing acetylated glycosyl bromides as well as aromatic moieties and mild glycosylation promoters. The aglycones, p-O-acetylate...

The synthesis of light-harvesting arrays requires modular pigment building blocks. Boron-dipyrromethene dyes are well-suited for the photochemical sensitization of free base or metalloporphyrins. Direct access to borondipyrromethene dyes bearing reactive substituents is provided by a simple synthetic route involving two one-flask reactions. Reaction of pyrrole or 2-methylpyrrole with an aldehyd...

The extended polycyclic aromatic hydrocarbons (PAHs) have received significant interdisciplinary attention due to their semiconducting applications in diverse organic electronics as well as intriguing structural interests of well-defined graphene segments. Herein, a highly efficient oxidative spirocyclization and 1,2-aryl migration tandem synthetic method for the construction of extended polyar...