A flavin mimic possessing strong oxidizing power due to electron delocalization: a benzo-dipteridine
作者:Yumihiko Yano、Michiaki Nakazato、Rafael E. Vasquez
DOI:10.1039/c39850000226
日期:——
7,14-Diethyl-3,10-dimethylbenzo[1,2-g,4,5-g]dipteridine-2,4,9,11(3H,7H,10H,14H)-tetrone [benzo-dipteridine (1)] shows remarkablyhighoxidizing activity towards thiols and phenylhydrazine; acid-catalysis is observed in the oxidation of an NADH model by (1).
7,14-二乙基-3,10-二甲基苯并[1,2- g,4,5 - g ]二哌啶-2,4,9,11(3 H,7 H,10 H,14 H)-四元[苯并-二哌啶(1)]显示出对硫醇和苯肼的极高的氧化活性;通过(1)在NADH模型的氧化中观察到酸催化。
Palladium-catalyzed amination of aryl dibromides with secondary amines: synthetic and mechanistic aspects
作者:Irina P. Beletskaya、Alla G. Bessmertnykh、Roger Guilard
DOI:10.1016/s0040-4039(99)01246-0
日期:1999.8
Diaminobenzenes are obtained starting from m- and p-dibromobenzenes and secondary amines in the presence of Pd(dba)2/P(o-tolyl)3and sodium tert-butoxide in moderate to good yields. Reductive dehalogenation of aryl dibromides is a major side reaction under these conditions. The study of this reaction has shown that the formation of reductive dehalogenation products occurs according to two independent ways. The
Pattern of OH radical reaction with N6,N6-dimethyladenosine. Production of three isomeric OH adducts and their dehydration and ring-opening reactions
作者:A. J. S. C. Vieira、S. Steenken
DOI:10.1021/ja00258a031
日期:1987.11
20 /sup 0/C) and activation parameters. With A-4-OH and A-5-OH, the transformations involve OH/sup -/ elimination (dehydration) (k = (4.2-4.9) x 10/sup 5/ s/sup -1/) to yield the radical cation DMAdo/sup .+/; with A-8-OH, opening of the imidazole ring occurs (k = 9.5 x 10/sup 4/ s/sup -1/). DMAdo/sup .+/ oxidizes N,N,N',N'-tetramethyl-p-phenylenediamine with k = 2.9 x 10/sup 9/ M/sup -1/ s/sup -1/
ESR and ENDOR Investigations on Various Wurster?s Radical Cations in Solution. Experimental Results, Theoretical Ab Initio, and DFT Calculations
作者:G�nter Grampp、Anne-Marie Kelterer、Stephan Landgraf、Michael Sacher、Dominique Niethammer、Jo�o P. Telo、Rui M. B. Dias、Abel J. S. C. Vieira
DOI:10.1007/s00706-004-0224-4
日期:2005.4
ESR and ENDOR spectra are reported of several symmetrical substituted N , N , N ′, N ′-tetraalkyl- p -phenylenediamine radical cations in solution. Different N , N ′-alkyl substituted para -phenylenediamines, like the ethyl, n -propyl, and iso -propyl derivative are compared with the parent N , N , N ′, N ′-tetramethyl- p -phenylenediamine ( Wurster ’s Blue Cation). N , N , N ′, N ′-Tetrabenzyl- p
报告了溶液中几个对称取代的 N , N , N ', N'- 四烷基- 对苯 二胺自由基阳离子的ESR和ENDOR光谱 。不同 Ñ , Ñ ' -烷基取代的 对 苯二胺类,如乙基, Ñ 丙基,和 异丙 丙基衍生物是与亲本相比 Ñ , Ñ , Ñ ', Ñ ' -四甲基- p 苯二胺( 沃斯特 的蓝阳离子)。 ñ 另外,还研究了 N , N ′, N′- 四苄基- 对苯 二胺,1,4-二吡咯烷基苯 和 N , N′- 双[4-(二甲基氨基)苯基]哌嗪。比较了实验和计算的超精细耦合常数。报告了乙腈中的特征性UV-VIS数据和氧化还原电位,以及化合物的合成。
Alpha-olefin polymerization catalyst, process for producing catalyst component and process for polymerizing alpha-olefins
申请人:Standard Oil Company
公开号:EP0015645A1
公开(公告)日:1980-09-17
Catalyst for the stereospecific polymerization of alpha-olefins of 3 or more carbon atoms comprising an organoaluminium compound and a component prepared from halogen-containing compound of titanium(IV), organic electron donor, and a pretreatment product of components comprising magnesium alcoholate, Group II or IIIA metal alkyl, and optionally, one or more pretreatment modifiers such as a mineral acid or anhydride of sulfur, organometallic chalcogenide derivative of hydrogen sulfide, organic acid or organic acid ester. Preferably, the product obtained from such materials is contacted with liquid Lewis acid and mechanically activated prior to polymerization use.