Chemical resolution of spiroindanones and synthesis of chiroptical polymers with circularly polarized luminescence.

Herein, the synthesis and chemical resolution of 1,1'-spirobisindane-3,3'-dione have been accomplished utilizing inexpensive and readily available benzaldehyde and acetone as starting materials, and (1R,2R)- or (1S,2S)-1,2-diphenylethane-1,2-diol as a recyclable chiral resolution reagent. The further transformation of R- and S-1,1'-spirobisindane-3,3'-dione into chiral monomers and polymers has been achieved by the reasonable design of the synthetic route and the optimization of the polymerization conditions. The resulting chiroptical polymers exhibit blue emission with thermally activated delayed fluorescence (TADF), excellent optical activities with circular dichroism intensities per molar absorption coefficient (gabs) of up to 6.4 × 10-3, and intense circularly polarized luminescence (CPL) with luminescence dissymmetry factor (glum) values of up to 2.4 × 10-3.

Dibenzo[b,d]furan/thiophene-fused double boron-based multiresonance emitters with narrowband ultrapure green electroluminescence.

Herein, double boron (DB)-based narrowband pure-green multiresonance (MR) emitters DBF-DBN and DBT-DBN have been designed and synthesized. Dibenzo[b,d]furan and dibenzo[b,d]thiophene as linkages between two B-N skeletons endow target DB-MR-emitters with a rigid and symmetric molecular structure, which efficiently extends the π-conjugation length and suppresses vibrational relaxation, resulting in a narrowband pure-green emission. DBT-DBN exhibits a remarkably higher reverse intersystem crossing (RISC) rate (kRISC = 7.4 × 105 s-1) than DBF-DBN (kRISC = 1.1 × 105 s-1) due to the heavy-atom effect of sulfur. The organic light-emitting diode (OLEDs) based on DBT-DBN shows an ultrapure green emission with maximum external quantum efficiencies (EQEs) up to 31.3%, an emission peak at 520 nm, and a narrow full-width at half-maximum (FWHM) of 24 nm, meeting the BT.2020 green standard.

Rh(III)-catalysed C-H/C-H cross-coupling of S-aryl sulfoximines with thiophenes: facile access to [1]benzothieno[3,2-b][1]benzothiophene (BTBT) and benzothiazines.

Reported herein is rhodium-catalysed oxidative C-H/C-H cross-coupling of S-aryl sulfoximines with thiophenes via a chelation-assisted strategy, which provides an efficient approach for the construction of [1]benzothieno[3,2-b][1]benzothiophene (BTBT) and benzothiazine skeletons from easily available substrates. This protocol exhibits a good compatibility with halogen substituents, thus paving the way for further transformation to prepare various organic functional molecules. The resulting benzothiazine derivative shows a deep blue emission with Commission Internationale de 'Eclairage (CIE) coordinates of (0.15, 0.04), a high quantum yield, and a delayed fluorescence lifetime.

[Effect of catgut implantation at "Yingxiang"(LI20) on lower airway remodeling in allergic rhinitis rats].

OBJECTIVE: To observe the effect of catgut implantation at "Yingxiang"(LI20) on lower airway remodeling and levels of osteopon-tin (OPN) protein in allergic rhinitis (AR) rats, so as to reveal its mechanisms underlying improvement of AR. METHODS: Male SD rats were randomly divided into control, model and catgut implantation groups, with 10 rats in each group. The AR model was established by intraperitoneal injection and nasal drip of ovalbumin. The catgut implantation was applied to bilateral "Yingxiang"(LI20) for 28 days in rats of the catgut implantation group. The total score of allergic symptoms of rats in each group were observed. The histopathological changes of lower airway were observed under light microscope after Hematoxylineosin, Periodic acid-Schiff and Masson staining. The expression of OPN protein was detected by immunohistochemistry and Western blot, separately. RESULTS: The total score of allergic symptoms of nose-wiping, running nose and sneezing, count of lung goblet cells, lung fiber content, and immunoactivity and expression levels of OPN protein were significantly increased in the model group in contrast to the control group (P<0.05). After the intervention, the total score of allergic symptoms, count of lung goblet cells, immunoactivity and expression levels of OPN protein were considerably down-regulated in the catgut implantation group relevant to the model group (P<0.05). H．E. stain showed thickening of partial airway wall, narrowing of lumen, increase of mucus section, widened alveolar septum, infiltration of inflammatory cells, lymphocytes and eosinophil around the bronchus and in the lung interstitium in AR rats, which was milder in the catgut implantation group. The immunoactivity and expression levels of OPN protein were positively related with the lung goblet cells count and lung fiber content (P<0.05，P<0.01). CONCLUSION: Acupoint implantation of catgut can improve pathological changes of lower airway remodeling, which may be related to its effect in down-regulating the expression of OPN protein in the lung tissue.

Transient directing ligand- and solvent-controlled C-H/C-H cross-coupling/quaternization cyclization/dequaternization of benzaldehydes with thiophenes.

Rh(iii)-Catalyzed oxidative C-H/C-H cross-coupling between benzaldehydes and thiophenes has been accomplished for the first time. In such reactions, transient directing ligands (TDLs) can not only promote ortho-C-H activation, but can also control the chemoselectivity through a suitable combination of different solvents.