Simple and brilliant : 1‐Substituted 1H‐indole‐2‐carboxylic acids efficiently undergo successive diarylation accompanied by C? H bond cleavage and decarboxylation upon treatment with aryl bromides in the presence of a palladium catalyst system to afford fluorescent 2,3‐diarylindoles. This facile synthetic method provides a highly efficient blue emitter with a quantum yield of 0.97 in the solid state (see scheme).
Aryl–alkyl cross‐coupling products are obtained by the iron‐catalyzed oxidative heterocoupling of organozinc reagents under mild conditions. This novel reaction pathway is versatile, allowing for the use of primary and secondary aliphatic diorganozinc reagents as coupling partners as well as tolerating functionalized aryl‐ and alkylzinc reagents.
Towards cooler solid oxide fuel cells: Disorder and dimensionality (see picture) play an important role in determining ion mobility of bulk and artificially nanolayered materials and should be considered in the design of new electrolytes with enhanced conductivity.
Once difficult to obtain , the title compounds can be prepared in virtually enantiomerically pure form with a bis(triorganostannyl) zinc reagent (see scheme). Subsequent diastereoselective thermal (left) and Lewis acid promoted reactions (right) illustrate the synthetic potential of these compounds.
Phosphorus meets carbohydrates : Dimethyl phosphite reacts with ceric(IV) ammonium nitrate (CAN) to give phosphonyl radicals that add to glycals 1 . The derivatives 2 were isolated in high yields and during a subsequent Horner–Emmons reaction underwent an interesting elimination to give 3,6‐dihydro‐2H‐pyrans 3 . The short sequence with simple precursors is applicable to the transformation of hexoses, pentoses, and disaccharides. Bn=benzyl.
Get selective! A selective oxidation of 1,2‐diols to α‐hydroxyketones catalyzed by organotin compounds has been developed (see scheme). Invaluable chemo‐ and stereoselectivity were found in the reaction. The catalytic system has been achieved by electrochemical and chemical oxidation.
Two very distinct chemical reactions, yet a single catalyst : A gold complex promotes the formation of tertiary enamines from a variety of terminal and internal alkynes. Subsequent addition of a terminal alkyne to the reaction mixture affords allenes (see scheme).
Secondary, but second to none : The use of secondary alkyl halides in transition‐metal‐catalyzed cross‐coupling reactions (see scheme) has advanced significantly over the last five years. Selected examples of these transformations are examined, including mechanistic and stereochemical aspects.
Enlarged scope by fluorinated mediators : Oxyl radicals are easily formed on boron‐doped diamond (BDD) electrodes and can be exploited for the ortho‐selective coupling to the corresponding biphenols (see scheme). At partial conversion, a clean transformation is achieved that can be applied to electron‐rich as well as fluorinated phenols.
π–π assisted : Photoinduced electron transfer from cofacial porphyrin dimers to electron acceptors is prominently accelerated, whereas the back electron transfer is decelerated, relative to the corresponding porphyrin monomer (see figure).
