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The synthesis and application of three examples of a new class of chiral (C(2)) atropisomeric diphosphines characterized by two interconnected five-membered heteroaromatic rings, with hindered rotation around the interanular bond, are described. Optically pure (+)- and (-)-2,2'-bis(diphenylphosphino)-4,4',6,6'-tetramethyl-3,3'-bibenzo[b]thiophene (tetraMe-bitianp) (1a) and the parent unsubstituted system (+)- and (-)-bitianp (1b) were synthesized. They were found to be optically stable at 100 degrees C and were successfully employed as ligands in the Ru(II)-catalyzed hydrogenation of alpha- and beta-oxo esters to the corresponding alpha- and beta-hydroxy esters and in the hydrogenation of olefinic substrates. The optical and chemical yields were comparable with those reported for the same Ru(II)-binap-catalyzed reactions carried out under the same experimental conditions. The 2,2'-bis(diphenylphosphino)-3,3'-bibenzo[b]furan (1c), the oxygenated analogue of bitianp, was found to be configurationally unstable at room temperature. Complete structural X-ray elucidation of the Pd complexes of 1a-c is reported. The advantages of these biheteroaromatic ligands over the classical biaryl systems are discussed.

A “charm bracelet” is a graphic description of the polymer prepared from cyclopentadithiophene with fullerene pendants. The interaction of the readily reducible fullerene moieties with the readily oxidizable polythiophene backbone makes 1 an interesting new material. Cyclic voltammetric studies have shown that the C60 substituents and the polythiophene chain retain their unique electrochemical properties in 1.

The isomeric ionones 1−3 are of both academic and commercial interest. Since their first preparation at the end of the 19th century they have been widely used as fragrances and as starting materials or building blocks in the synthesis of many relevant products. The regioselective and/or enantioselective preparation of ionones has therefore been investigated with growing interest over the last decades. In this Microreview, we summarize the syntheses of optically active α‐ and γ‐ionones (1, 3) and the epoxy and dihydro ionones 4−7. In addition, the olfactory properties of most of them are reported comprehensively.

The coupling of the enantioselective reduction catalyzed by Old Yellow Enzymes (OYEs), together with the in situ substrate feeding product removal (SFPR) concept, significantly improved the productivity of the g-scale preparation of ethyl (S)-2-ethoxy-3-(p-methoxyphenyl)propanoate (EEHP), an important precursor of several PPAR-α/γ agonists, such as Tesaglitazar. The OYEs and the glucose dehydrogenase for cofactor regeneration were cloned, overexpressed in Escherichia coli, and purified. The synthetic sequence was completed by a NaClO2 oxidation employing cheap and environmentally friendly conditions. The product was obtained in 94% yield and with an ee of 98% over the two steps.

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Cyclovoltammetric analysis has shown that anodic coupling of 2,2'-bipyrrole in acetonitrile is influenced by the electron-donor properties of the anion of the supporting electrolyte. 2,2'-Bipyrrole oxidation in the presence of poor electron-donor anions (C104-, PFg-, BF4", CF3SO3-) occurs in a one-electron process at a potential independent of the anion, yielding the dimer whereas with more electron-donor anions (tosylate, benzenesulfonate, methanesulfonate, camphorsulfonate, chloride, and nitrate) the oxidation process is shifted to lower potentials according to the anion type and concentration, requires 2.5 electrons/bipyrrole unit and results in polypyrrole formation. The results are explained by ion pairing and hydrogen bonding of the electron-rich anion with the initially produced radical cation to form a highly reactive radical species. As a consequence, the well-known favorable action of tosylate in promoting polypyrrole formation may be satisfactorily accounted for by a chemical homogeneous process rather than by morphological factors.