InI-catalyzed polyene cyclization of allenes and its application in the total synthesis of seven abietane-type diterpenoids.

A novel polyene cyclization using the allene group as the initiator has been successfully developed. This methodology provides an efficient strategy for the construction of an abietane-type tricyclic skeleton with a functionalizable C2-C3 double bond and features a wide substrate scope and excellent stereoselectivities. Potential utility of this approach has been well demonstrated by the collective total synthesis of seven abietane-type diterpenoids.

Synthesis and biological activity of squaramido-tethered bisbenzimidazoles as synthetic anion transporters.

A series of squaramido-tethered bisbenzimidazoles were synthesized from the reaction of diethyl squarate with substituted 2-aminomethylbenzimidazoles. These conjugates exhibit moderate binding affinity toward chloride anions. They are able to facilitate the transmembrane transport of chloride anions most probably an anion exchange process, and tend to be more active at acidic pH than at physiological pH.

Facile access to diverse all-carbon quaternary center containing spirobicycles by exploring a tandem Castro-Stephens coupling/acyloxy shift/cyclization/semipinacol rearrangement sequence.

Efficient combination of two or more reactions into a practically useful purification free sequence is of great significance for the achievement of structural complexity and diversity, and an important approach for the development of new synthetic strategies that are industrially step-economic and environmentally friendly. In this work, a facile and efficient method for the construction of highly functionalized spirocyclo[4.5]decane derivatives containing a synthetically challenging quaternary carbon center has been successfully developed through the realization of a tandem Castro-Stephens coupling/1,3-acyloxy shift/cyclization/semipinacol rearrangement sequence.

A simple and efficient approach toward deep-red to near-infrared-emitting iridium(iii) complexes for organic light-emitting diodes with external quantum efficiencies of over 10.

While the external quantum efficiency (EQE) of iridium(iii) (Ir(iii)) phosphor based near-infrared organic light-emitting diodes (NIR OLEDs) has been limited to 5.7% to date, there is no significant EQE improvement for these types of OLEDs due to the lack of efficient Ir(iii) emitters. Here, a convenient approach within three synthetic steps is developed to afford two novel and efficient deep-red to near-infrared (DR-NIR) emitting phosphors ( and ), in which a cyano group is added into a commercial red emitter named to significantly stabilize the lowest unoccupied molecular orbitals of the newly designed Ir(iii) complexes.

Antibacterial activity and mechanism of action of a thiophenyl substituted pyrimidine derivative.

The issue of multidrug resistant bacteria is a worldwide health threat. To develop new antibacterial agents with new mechanisms of action is thus an urgent request to address this antibiotic resistance crisis. In the present study, a new thiophenyl-pyrimidine derivative was prepared and utilized as an effective antibacterial agent against Gram-positive strains.

Correction: A study on a telo21 G-quadruplex DNA specific binding ligand: enhancing the molecular recognition ability the amino group interactions.

[This corrects the article DOI: 10.1039/C8RA03833C.].

A study on a telo21 G-quadruplex DNA specific binding ligand: enhancing the molecular recognition ability the amino group interactions.

A symmetric ligand is synthesized composed of a core -methylpyridinium scaffold and two -substituted benzyl groups through a flexible ethylene bridge to form a novel three-ring-conjugated system. The ligand system was found to have only weak background fluorescent signal in aqueous or physiological conditions and exhibited strong fluorescent signal enhancement targeting at telo21 G-quadruplex structure rather than other types of nucleic acids. The comparison study with two terminal groups (-N(CH) -SCH) indicates that the stimulated signal enhancement of specific binding is probably attributed to the hydrogen-bonding interactions through the amino groups in the G-quartets.