Highly Efficient Solution-Processed Organic Light-Emitting Diodes Containing a New Cross-linkable Hole Transport Material Blended with Commercial Hole Transport Materials.

A new small-molecular thermally cross-linkable material {[4-(9-phenyl-9H-carbazol-4-yl)phenyl]-bis-(4'-vinylbiphenyl-4-yl)-amine} (PCP-bis-VBPA, PbV) containing the styrene moiety was synthesized for hole transport layers in wet processed organic light-emitting diodes (OLEDs). It was found that PbV exhibited relatively high glass temperatures above 154 °C and a triplet energy (T1) greater than 2.81 eV. This new synthetic hole transport material (HTM) forms very uniform films after cross-linking reaction with little pin-holes, although it was small-molecule-based cross-linkable HTM. However, to solve the certain minor non-uniformity caused by pinholes with various sizes, a semi-interpenetrating network was formed with well-known polymeric HTM with high mobility [e.g., poly(9,9-dioctylfluorene-co-N-(4-butylphenyl)diphenyl amine), TFB, or poly(N,N'-bis-4-butylphenyl-N,N'-bisphenyl)benzidine, poly-TPD]. As a result, we successfully fabricated red phosphorescent OLED showing an efficiency of about 16.7 cd/A and 12.4% (external quantum efficiency) if we applied PbV blended with 20% of TFB or poly-TPD. In particular, the efficiency and lifetime are significantly improved by 1.5 and 4.5 times, respectively, compared to those of the control device without using blended HTM.

A highly stereoselective sequential allylic transfer reaction of diene with diboronyl reagent and aldehydes promoted by nickel catalyst.

[reaction: see text] A new protocol for the sequential allylic transfer reaction of a diene with two aldehydes in the construction of cyclic systems containing four stereogenic centers is achieved in a one-pot operation. Reaction of the diene-alehyde 1 with aldehyde in the presence of the diboronyl reagent catalyzed by a nickel complex produces products 2 and 3 depending on reaction conditions in high levels of diastereoselectivity. Extension of this method to the synthesis of six-membered rings is also investigated.

Highly diastereoselective Prins-type cyclisation of cyclopropylvinylic aldehydes mediated by TiCl4.

A novel intramolecular Prins type cyclisation of cyclopropylvinylic aldehydes promoted by TiCl(4) under mild reaction conditions to form cis-cyclic products in high yields has been accomplished.

Interleukin-1beta induces MUC2 gene expression and mucin secretion via activation of PKC-MEK/ERK, and PI3K in human airway epithelial cells.

Interleukin 1beta(IL-1beta), a proinflammatory cytokine, is related with inflammatory diseases and it up-regulates MUC2 gene expression and mucin secretion. This study was designed to investigate the signal transduction pathway of the IL-1beta-mediated MUC2 gene expression and mucin secretion in human airway epithelial cells. In cultured human airway NCI-H292 epithelial cells, the steady state of the mRNA level of MUC2 gene expression and mucin secretion induced by IL-1beta were determined by reverse transcriptase-polymerase chain reaction (RT-PCR), enzyme immunoassay, and immunoblot analysis. To observe the signal pathway of the IL-1beta-mediated MUC2 gene expression and mucin secretion, we used several specific inhibitors. PD98059 (MEK/ERK inhibitor) suppressed IL-1beta-mediated MUC2 gene expression and mucin secretion, while SB203580 (p38 inhibitor) did not. Ro31-8220 (PKC inhibitor) inhibited IL-1beta-mediated MUC2 gene expression and mucin secretion. It inhibited ERK phosphorylation, but did not inhibit p38 phosphorylation. LY294002 (PI3K inhibitor) also suppressed MUC2 expression, but did not inhibit any MAPKs phosphorylation. These results suggest that the IL-1beta-mediated MUC2 gene expression and mucin secretion in NCI-H292 cells are regulated through activation of the PKC-MEK/ERK pathway, and that PI3K is also involved in the IL-1beta-mediated MUC2 gene expression and mucin secretion.

Interleukin-1beta induces MUC2 and MUC5AC synthesis through cyclooxygenase-2 in NCI-H292 cells.

Interleukin-1beta (IL-1beta) has been implicated in the pathogenesis of inflammatory diseases of the airway. In this study, we investigated the regulation of MUC2 and MUC5AC expression and of their regulatory mechanisms through cyclooxygenase-2 (COX-2) and prostaglandin E(2) (PGE(2)). Cells activated by IL-1beta showed increased COX-2, MUC2, and MUC5AC expressions at both the mRNA and protein levels. Mucin production was blocked by the selective COX-2 inhibitor NS398, and PGE(2) directly induced MUC2 and MUC5AC expression at both the mRNA and protein levels in a dose-dependent manner. These results suggest a role for PGE(2) in IL-1beta-induced mucin synthesis in NCI-H292 cells. To investigate the roles of molecules upstream of COX-2 in mucin regulation, we examined the role of mitogen-activated protein kinases (MAPKs). Cells activated by IL-1beta showed increased extracellular signal-regulated kinase (ERK)1/2 and p38 phosphorylation, and IL-1beta-induced MUC2 and MUC5AC production was blocked by the ERK pathway inhibitor PD98059 or the p38 inhibitor SB203580. The inhibition of both MAPKs reduced IL-1beta-induced COX-2 expression and PGE(2) synthesis. Furthermore, the addition of PGE(2) to cells overcame the inhibitory effects of both MAPK inhibitors in IL-1beta-induced mucin production. These results indicate that in human pulmonary epithelial cells, IL-1beta activates ERK or p38 to induce COX-2 production, which in turn induces MUC2 and MUC5AC production.

cis-stereoselective nickel-catalyzed cyclization/alkylation and arylation reactions of allenyl-aldehydes and -ketones with organozinc reagents.

Highly stereoselective alkylative and arylative cyclization reactions of allenyl-aldehydes and -ketones with organozinc reagents occur efficiently in the presence of catalytic Ni(COD)2 to afford cis-fused homoallylic cyclopentanols.