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1.
We compute the cyclic homology of the coordinate ring A(SLq(2)) of the quantum algebraic group SL
q
(2). We observe a degeneration of the noncommutative de Rham complex. The results are also verified from the point of view of Connes' noncommutative differential geometry. 相似文献
2.
M Mitsukuchi J Nakagami T Ikemoto S Higuchi Y Tarumoto H Yasui K Sota 《Chemical & pharmaceutical bulletin》1989,37(6):1534-1539
A series of 17-succinyl derivatives of four corticosteroids was prepared. They were tested for vasoconstrictive activity in humans, using 9 alpha-fluoro-11 beta, 21-dihydroxy-16 beta-methyl-17 alpha-valeryloxy-1,4-pregnadiene-3,20-dione (betamethasone 17-valerate, BV) as a standard. The activities of the 21-chloro 17-methylsuccinate compounds (6A, 6C and 6D) were greater than that of BV. A structure-activity relationship study showed that the activities of the 21-chloro 17-methylsuccinates were more potent than those of the corresponding 21-esters. 相似文献
3.
Anti-allergic activities of lyophilized pig bile [( PB]) were examined in mice with picryl chloride-induced contact dermatitis (PC-CD), an experimental model of delayed-type hypersensitivity (DTH; type-IV allergy). PC-CD was markedly inhibited by an oral administration of [PB] within 4 h after but not during 8 to 16 h after challenge with picryl chloride. Anti-inflammatory activities of [PB] were also examined in acetic acid-induced mouse increased vascular permeability, hypotonic-hyperthermic lysis of rat erythrocytes and carrageenin-induced rat hind paw edema. [PB] had no effect on these models. The present study suggests that [PB] inhibits PC-CD through its immuno-modulation in the inductive phase of DTH rather than by an anti-inflammatory action. 相似文献
4.
Prof. Dr. Junfeng Yang Yuto Mori Prof. Masahiro Yamanaka Prof. Naohiko Yoshikai 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(37):8302-8307
A simple cobalt-diphosphine catalyst has been found to efficiently promote intramolecular cyclization of ortho-cyclopropylvinyl- and cyclopropylidenemethyl-substituted benzaldehydes into benzocyclooctadienone and benzocycloheptadienone derivatives, respectively. This ring-opening hydroacylation likely involves aldehyde C−H oxidative addition, olefin insertion, cyclopropane cleavage by β-carbon elimination, and C−C bond-forming reductive elimination, as was supported by mechanistic experiments and DFT calculations. 相似文献
5.
6.
Prof. Takanori Suzuki Yuto Sakano Dr. Tomohiro Iwai Dr. Shinichi Iwashita Dr. Youhei Miura Dr. Ryo Katoono Prof. Hidetoshi Kawai Prof. Kenshu Fujiwara Prof. Yasushi Tsuji Prof. Takanori Fukushima 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(1):117-123
When two benzene rings are fused to a tetraaryl‐o‐quinodimethane skeleton, sterically hindered helical molecules 1 acquire a high thermodynamic stability. Because the tetraarylbutadiene subunit contains electron‐donating alkoxy groups, 1 undergo reversible two‐electron oxidation to 2 2+, which can be isolated as deeply colored stable salts. Intramolecular transfer of the point chirality (e.g., sec‐butyl) on the aryl groups to helicity induces a diastereomeric preference in dications 2 b 2+ and 2 c 2+, which represents an efficient method for enhancing circular‐dichroism signals. Thus, those redox pairs can serve as new electrochiroptical response systems. X‐ray analysis of dication 2 2+ revealed π–π stacking interaction of the diarylmethylium moieties, which is also present in solution. The stacking geometry is the key contributor to the chirosolvatochromic response. 相似文献
7.
Chiral Palladacycle Catalysts Generated on a Single‐Handed Helical Polymer Skeleton for Asymmetric Arylative Ring Opening of 1,4‐Epoxy‐1,4‐dihydronaphthalene
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Dr. Takeshi Yamamoto Yuto Akai Prof. Dr. Michinori Suginome 《Angewandte Chemie (International ed. in English)》2014,53(47):12785-12788
Post‐polymerization C? H activation of poly(quinoxaline‐2,3‐diyl)‐based helically chiral phosphine ligands (PQXphos) with palladium(II) acetate afforded chiral phosphapalladacycles quantitatively. In situ generated palladacycles exhibited enantioselectivities up to 94 % ee in the palladium‐catalyzed asymmetric ring‐opening arylation of 1,4‐epoxy‐1,4‐dihydronaphthalenes with arylboronic acids. 相似文献
8.
Elaine Tsui Anthony J. Metrano Yuto Tsuchiya Robert R. Knowles 《Angewandte Chemie (International ed. in English)》2020,59(29):11845-11849
We report a catalytic, light‐driven method for the intramolecular hydroetherification of unactivated alkenols to furnish cyclic ether products. These reactions occur under visible‐light irradiation in the presence of an IrIII‐based photoredox catalyst, a Brønsted base catalyst, and a hydrogen‐atom transfer (HAT) co‐catalyst. Reactive alkoxy radicals are proposed as key intermediates, generated by direct homolytic activation of alcohol O?H bonds through a proton‐coupled electron‐transfer mechanism. This method exhibits a broad substrate scope and high functional‐group tolerance, and it accommodates a diverse range of alkene substitution patterns. Results demonstrating the extension of this catalytic system to carboetherification reactions are also presented. 相似文献
9.
Hisatoyo Morinaga Yusuke Ujihara Naho Yuto Daisuke Nagai Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》2011,49(24):5210-5216
Metal‐free controlled ring‐opening polymerization of glycidyl phenyl ether (GPE) was achieved using tetra‐n‐butylammonium fluoride (Bu4NF) as an initiator in the presence of water and ethanol as chain transfer agents (CTAs). Number‐averaged molecular weight of poly(GPE) increased with an increase of [GPE]0/([Bu4NF]0 + [CTA]0) values, showing relatively narrow molecular weight distributions. NMR spectroscopic analysis exhibited a formation of ethoxy groups as well as FCH2 at the initiating polymer chain‐end when ethanol was used as the CTA in the polymerization. These results indicate that Bu4NF acts as a catalyst as well as the initiator for this polymerization system. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
10.
We consider the numerical integration of the Hunter–Saxton equation, which models the propagation of weakly nonlinear orientation waves. For the equation, we present two weak forms and their Galerkin discretizations. The Galerkin schemes preserve the Hamiltonian of the equation and can be implemented with cheap H~1 elements. Numerical experiments confirm the effectiveness of the schemes. 相似文献