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121.
Carbazole Dendrimers as Solution‐Processable Thermally Activated Delayed‐Fluorescence Materials
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Assist. Prof. Ken Albrecht Assist. Prof. Kenichi Matsuoka Assoc. Prof. Katsuhiko Fujita Prof. Kimihisa Yamamoto 《Angewandte Chemie (International ed. in English)》2015,54(19):5677-5682
Recently, thermally activated delayed fluorescence (TADF) materials have received increasing attention as effective emitters for organic light‐emitting diodes (OLEDs). However, most of them are usually employed as dopants in a host material. In this report, carbazole dendrimers with a triphenyl‐s‐triazine core are reported, which are the first solution‐processable, non‐doped, high‐molecular‐weight TADF materials. The dendrimers were obtained by a new and facile synthetic route using the tert‐butyldimethylsilyl moiety as a protecting group. All dendrimers showed TADF in toluene. Measurements of the temperature‐dependent luminescence lifetime revealed that spin‐coated neat films also showed TADF with moderate quantum yields. OLED devices incorporating these dendrimers as spin‐coated emitting layers gave external quantum efficiencies of up to a 3.4 %, which suggests that this device is harvesting triplet excitons. This result indicates that carbazole dendrimers with attached acceptors are potential TADF materials owing to their polarized electronic structure (with HOMO–LUMO separation). 相似文献
122.
Ryosuke Sakae Dr. Koji Hirano Prof. Dr. Tetsuya Satoh Prof. Dr. Masahiro Miura 《Angewandte Chemie (International ed. in English)》2015,54(2):613-617
A copper‐catalyzed aminoboration of bicyclic alkenes, including oxa‐ and azabenzonorbornadienes, has been developed. With this method, amine and boron moieties are simultaneously introduced at an olefin with exo selectivity. Subsequent stereospecific transformations of the boryl group can provide oxygen‐ and nitrogen‐rich cyclic molecules with motifs that may be found in natural products or pharmaceutically active compounds. Moreover, a catalytic asymmetric variant of this transformation was realized by using a copper complex with a chiral bisphosphine ligand, namely (R,R)‐Ph‐BPE. 相似文献
123.
M. Sc. Yasemin Akbulut Hannah J. Gaunt Prof. Katsuhiko Muraki Dr. Melanie J. Ludlow Dr. Mohamed S. Amer Dr. Alexander Bruns Dr. Naveen S. Vasudev Dr. Lea Radtke Dr. Matthieu Willot M. Sc. Sven Hahn M. Sc. Tobias Seitz Dr. Slava Ziegler Prof. Dr. Mathias Christmann Prof. Dr. David J. Beech Prof. Dr. Herbert Waldmann 《Angewandte Chemie (International ed. in English)》2015,54(12):3787-3791
Current therapies for common types of cancer such as renal cell cancer are often ineffective and unspecific, and novel pharmacological targets and approaches are in high demand. Here we show the unexpected possibility for the rapid and selective killing of renal cancer cells through activation of calcium‐permeable nonselective transient receptor potential canonical (TRPC) calcium channels by the sesquiterpene (?)‐englerin A. This compound was found to be a highly efficient, fast‐acting, potent, selective, and direct stimulator of TRPC4 and TRPC5 channels. TRPC4/5 activation through a high‐affinity extracellular (?)‐englerin A binding site may open up novel opportunities for drug discovery aimed at renal cancer. 相似文献
124.
Dr. Ayumi Hirano‐Iwata Yutaka Ishinari Dr. Hideaki Yamamoto Prof. Michio Niwano 《化学:亚洲杂志》2015,10(6):1266-1274
Ion channel proteins provide gated pores that allow ions to passively flow across cell membranes. Owing to their crucial roles in regulating transmembrane ion flow, ion channel proteins have attracted the attention of pharmaceutical investigators as drug targets for use in the studies of both therapeutics and side effects. In this review, we discuss the current technologies that are used in the formation of ion channel‐integrated bilayer lipid membranes (BLMs) in microfabricated devices as a potential platform for next‐generation drug screening systems. Advances in BLM fabrication methodology have allowed the preparation of BLMs in sophisticated formats, such as microfluidic, automated, and/or array systems, which can be combined with channel current recordings. A much more critical step is the integration of the target channels into BLMs. Current technologies for the functional reconstitution of ion channel proteins are presented and discussed. Finally, the remaining issues of the BLM‐based methods for recording ion channel activities and their potential applications as drug screening systems are discussed. 相似文献
125.
Highly Chemoselective and Versatile Method for Direct Conversion of Carboxylic Acids to Ketones Utilizing Zinc Ate Complexes
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Various carboxylic acids were directly transformed into the corresponding ketones by utilizing organozinc ate complexes, which provide high chemoselectivity without any overreaction to the undesired tertiary carbinol, owing to formation of a stable tetrahedral zincioketal intermediate. This method offers good overall atom/step/pot economy and operational simplicity. 相似文献
126.
Runyan Ni Naoto Mitsuda Takeru Kashiwagi Kazunobu Igawa Katsuhiko Tomooka 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(4):1206-1210
A variety of medium‐sized cycloalkynes were efficiently synthesized by the double Nicholas reaction of cobalt complex and bis(hetero)substituted acyclic compound. The alkyne moiety within the ring has a unique bent structure and high reactivity toward cycloaddition reactions. Furthermore, preparation of multifunctionalized alkynes was achieved by embedding the cycloalkyne within a peptide chain. 相似文献
127.
128.
Various N,N-dimethyl amides, N-methoxy-N-methyl amides, and isopropyl esters were smoothly transformed into the corresponding nitriles in good to moderate yields by the treatment with diisobutylaluminium hydride, followed by treatment with molecular iodine in aq ammonia. The present reactions are novel one-pot and practical methods for the transformation of N,N-disubstituted amides and isopropyl esters into nitriles, through the formation of hemiaminal O-AlBu2 and hemiacetal O-AlBu2, respectively. 相似文献
129.
Liu B Nakata K Sakai M Saito H Ochiai T Murakami T Takagi K Fujishima A 《Langmuir : the ACS journal of surfaces and colloids》2011,27(13):8500-8508
A facile new method that combines electrospray and hydrothermal treatment is used to prepare mesoporous core-shell TiO(2) spheres with high specific surface areas and high pore volumes. Interestingly, the resulting TiO(2) spheres are composed of anatase TiO(2) nanocrystals with exposed step-like {001} and smooth {010} facets. The percentage of exposed {001} facets can be adjusted by changing the experimental parameters used in the electrospray and hydrothermal treatment processes, such as the contents of poly(N-vinyl-2-pyrrolidone) and acetic acid. The combination of high specific surface area (>100 m(2) g(-1)), high pore volume (>0.30 cm(3) g(-1)), useful pore size (10-15 nm), spherical core-shell structure, and exposed high energy facets makes these TiO(2) spheres an important candidate for use in many photoelectrochemical applications. The formation mechanism of the mesoporous TiO(2) spheres is also studied. The great advantage of this method is that interesting and complicated mesoporous superstructures can be prepared using electrospray technology. 相似文献
130.
A remarkable effect of ionic liquids in transition-metal-free aerobic oxidation of benzylic alcohols
Yoshiro OdaKoji Hirano Tetsuya SatohSusumu Kuwabata Masahiro Miura 《Tetrahedron letters》2011,52(41):5392-5394
The transition-metal-free aerobic oxidation of benzylic alcohols is uniquely accelerated by a 1-butyl-3-methylimidazolium hexafluorophosphate (BMI-PF6)/PhCF3 biphasic system and Cs2CO3 to afford the corresponding ketones in good yields. The reaction system is also applicable to an oxidative cross-esterification of primary benzyl alcohols with a higher aliphatic alcohol. 相似文献