Supramolecular chirality and liquid crystalline OFET : Achiral end‐capped oligothiophenes can be tuned to exhibit supramolecular chirality with unique striped textures showing distinct circular dichroism signals as well as a highly ordered SmE phase that leads to high hole carrier mobility.
Green and fast : Allylation of aromatic and aliphatic thiols, by using allyl alcohols as substrates, requires only minutes at ambient temperature with a Ru catalyst (see scheme). Quantitative conversion is normal and the catalyst possesses high functional‐group tolerance.
Picky ferryl : The complex [Fe(Tp)(BF)] (Tp=hydrotris(3,5‐diphenylpyrazolyl)borate; BF=benzoylformate) reacts with O2 to generate an oxidant (see picture; O red, pink; Fe yellow; N blue; C gray; H white) that oxidizes added hydrocarbons shape‐selectively. Discrimination derives from a cleft formed by two phenyl groups of the Tp ligand, favoring oblate spheroidal substrates.
One‐nucleotide differences in microRNAs (miRNAs) can be discriminated in an assay based on a branched rolling‐circle amplification (BRCA) reaction and fluorescence quantification. With the proposed method miRNA can be detected at concentrations as low as 10 fM , and the miRNA in a total RNA sample of a few nanograms can be determined.
PS, I love you! Novel mixed phosphole/thiophene π‐conjugated systems were synthesized and their electronic properties have been studied both experimentally by UV/Vis spectroscopy and electrochemistry and by theoretical calculations. Exploiting the chemistry of both P‐ and S‐heteroles allows the generation of a diverse range of novel ring‐fused benzophosphole–thiophene derivatives.
Tracking down potential killers : Strong host–guest interactions enable the facile combination of polycationic cyclodextrin binding motifs (blue) with fluorescent reporters (orange) tethered to a hydrophobic guest molecule (dark green). An array of supramolecular fluorescent receptors prepared by this modular approach was used for the pattern‐based recognition of negatively charged contaminants in the anticoagulant drug heparin.
Well concealed : 1,2‐oxazines such as 1 rearrange under Lewis acidic conditions to bicyclic products of type 2 , which can be incorporated into oligosaccharides as protected amino sugar equivalents. Subsequent reductive steps provide unusual oligosaccharides 3 having C2‐branched 4‐amino sugar units. Most of the reactions proceed with excellent stereocontrol and allow the synthesis of a collection of stereoisomers.
A new strategy for the highly stereoselective synthesis of three stereoisomers of chiral 1,2,3‐trisubstituted cyclopropanes in good yields with excellent diastereoselectivities and very high enantioselectivities (up to >99 % ee) was developed via selenonium ylides (see scheme). Possible pathways for the asymmetric cyclopropanations were also proposed.
