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Among inherently chiral selectors of axial stereogenicity, usually resulting in very good enantiodiscrimination performances, the biindole‐based family has the additional advantage of very easy functionalization of the two nitrogen atoms with a variety of substituents with desirable properties. Aiming to evaluate the possibility of exploiting such feature to enhance the enantiodiscrimination ability of the archetype structure, a series of three inherently chiral monomers were designed and synthesized, characterised by a 2,2'‐biindole atropisomeric core conjugated to bithiophene wings enabling fast and regular electrooligomerization, and functionalised at the nitrogen atoms with an ethyl, a methoxyethyl, or a hydroxyethyl substituent. Nitrogen alkylation was also exploited to obtain for the first time the chemical resolution of the biindole selectors without employing chiral HPLC. The enantiodiscrimination ability of the selector series was comparatively evaluated in proof‐of‐concept chiral voltammetry experiments with a "benchmark" chiral ferrocenyl probe as well as with chiral non‐steroidal anti‐inflammatory drugs naproxen and ketoprofen. The large enantiomer potential differences for all probes increased in the ethyl < methoxyethyl ≪ hydroxyethyl sequence of selector substituents, supporting our assumption on the beneficial role of an additional coordination element. The powerful hydroxyethyl selector was also applied to ketoprofen in a commercial drug matrix. [ABSTRACT FROM AUTHOR]

An environmentally friendly and sustainable approach was adopted to produce a molecularly imprinted polymer (MIP) via electropolymerization, with remarkable electrochemical sensing properties, tested in tyrosine (tyr) detection. The 2,2′-bis(2,2′-bithiophene-5-yl)-3,3′-bithianaphtene (BT2-T4) was chosen as functional monomer and MIP electrosynthesis was carried out via cyclic voltammetry on low-volume (20 μL) screen-printed carbon electrodes (C-SPE) in ionic liquid 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ((BMIM) TFSI). An easy and rapid washing treatment allowed us to obtain the resulting MIP film, directly used for tyr electrochemical detection, carried out amperometrically. The sensor showed a linear response in the concentration range of 15–200 μM, with LOD of 1.04 µM, LOQ of 3.17 μM and good performance in selectivity, stability, and reproducibility. Tyrosine amperometric detection was also carried out in human plasma, resulting in a satisfactory recovery estimation. The work represents the first use of BT2-T4 as a functional monomer for the production of a molecularly imprinted polymer, with a green approach afforded by using a few microliters of a room temperature ionic liquid as an alternative to common organic solvents on screen-printed carbon electrodes, resulting in a valuable system that meets the green chemistry guidelines, which is today an essential criterion in both research and application field. [ABSTRACT FROM AUTHOR]

In this paper it is experimentally demonstrated that the electron‐spin/molecular‐handedness interaction plays a fundamental role in the chiral recognition process. This conclusion is inferred comparing current versus potential (I–V) curves recorded using chiral electrode surfaces, which are obtained via chemisorption of an enantiopure thiophene derivative: 3,3′‐bibenzothiophene core functionalized with 2,2′‐bithiophene wings (BT2T4). The chiral recognition capability of these chiral‐electrodes is probed via cyclic voltammetry measurements, where, Ag nanoparticles (AgNPs) capped with enantiopure BT2T4 (BT2T4@AgNP) are used as the chiral redox probe. Then, the interface handedness is explored by recording spin‐polarized I–V curves in spin‐dependent electrochemistry (SDE) and magnetic‐conductive atomic force microscopy (mc‐AFM) experiments. The quality of the interfaces is thoroughly cross‐checked using X‐ray photoemission spectroscopy, Raman, electrodesorption measurements, which further substantiate the metal(electrode)‐sulfur(thiophene) central role in the chemisorption process. Spin‐polarization values of about 15% and 30% are obtained in the case of SDE and mc‐AFM experiments, respectively. [ABSTRACT FROM AUTHOR]

Herein, we report on the synthesis and high-performance liquid chromatography (HPLC) resolution of a new atropisomeric C2-symmetry chiral monomer based on the 3,3′-bithiophene core, which was developed to produce novel, inherently oligomeric chiral electroactive materials. The analytical enantioseparation was optimized using the cellulose-type Chiralpak IB-3 column and a mixture of n-hexane–methanol–dichloromethane 90:5:5 (v/v/v) as the mobile phase. During the scale-up of the enantioseparation analytical conditions to a semipreparative level, remarkable deformations in the HPLC profile, such as peak splitting and plateau zones between enantiomeric peaks, were observed. We demonstrate the effects of sample diluent as they relate to distorted peak profiles, as well as provide experimental solutions to prevent the disturbing phenomenon. The optimized chromatographic conditions were exploited to collect milligram amounts of the enantiopure sample, which was submitted to chiroptical and stereochemical characterization studies. [ABSTRACT FROM AUTHOR]

Microfluidic valves based on chemically responsive materials have gained considerable attention in recent years. Herein, a wireless enantio‐responsive valve triggered by bipolar electrochemistry combined with chiral recognition is reported. A conducting polymer actuator functionalized with the enantiomers of an inherently chiral oligomer was used as bipolar valve to cover a tube loaded with a dye and immersed in a solution containing chiral analytes. When an electric field is applied, the designed actuator shows a reversible cantilever‐type deflection, allowing the release of the dye from the reservoir. The tube can be opened and closed by simply switching the polarity of the system. Qualitative results show the successful release of the colorant, driven by chirality and redox reactions occurring at the bipolar valve. The device works well even in the presence of chemically different chiral analytes in the same solution. These systems open up new possibilities in the field of microfluidics, including also controlled drug delivery applications. [ABSTRACT FROM AUTHOR]

The role played by the electronic properties and the steric features of bis(oxazoline) ligands in the Cu(I)-catalyzed cyclopropanation of styrene effected with ethyl diazoacetate was investigated. Two pairs of new bis(oxazolines) displaying flexible and atropisomeric 3,3'-bithiophene backbones were synthesized and structurally and electronically characterized.

Synthesis of 3,3-bis(diphenylphospino)-1,1'-dimethyl-2,2`biindole (N-Me-2-BINP) and 3,3-bis(diphenylphospino)-1,1'-bis(methoxymethyl)-2,2`-biindole (N-Me-2-BINP) is investigated. Reactions were found to be fast and enantioselection quite good.

Research demonstrates the synthesis of the chelating ligand enantiopure (plus)- and (minus)- 2,2',5,5'-tetramethyl-4,4'-bis(diphenylphosphino)-3,3'-bithiophene exhibiting a C(sub)2-symmetry. The electron rich metal associated diphosphine serves as catalysts in homogeneous hydrogenation of prostereogenic carbonyl functions.

The optically pure bis(diphenylphosphino)bibenzo[b]thiophenes tetraMe-bitianp and 4,5-demethylbenzo[b]thiophene belong to a new class of chiral ligands. The diphosphines can be utilized for asymmetric homogeneous catalysis with high enantioselectivity that is similar to binap ligands. The chiral ligands are composed of metallacycle with two interconnected five-membered units that exhibit good catalytic ability. The electronic properties of the phosphine groups and the configurational stability of the ligand depends on the type of heterocyclic system.