Transition‐metal‐catalyzed reactions of 5‐methylene‐2‐oxazolidinone and 5‐methylene‐1,3‐thiazolidine‐2‐thione with isocyanates

5‐Methylene‐2‐oxazolidinone (1) and 5‐methylene‐1,3‐thiazolidine‐2‐thione (4) react with various isocyanates to give the corresponding urethanes 3 and 5 in high yields in the presence of palladium(0) or palladium(II) catalyst under mild reaction conditions. A mechanism is proposed. Copyright © 2003 John Wiley & Sons, Ltd.     

Fluorinated,crosslinkable terpolymers based on vinylidene fluoride and bearing sulfonic acid side groups for fuel‐cell membranes

The radical terpolymerization of 8‐bromo‐1H,1H,2H‐perfluorooct‐1‐ene with vinylidene fluoride (VDF) and perfluoro(4‐methyl‐3,6‐dioxaoct‐7‐ene) sulfonyl fluoride is presented. Changing the feed compositions of these three fluorinated comonomers enabled us to obtain different random‐type poly[vinylidene fluoride‐ter‐perfluoro(4‐methyl‐3,6‐dioxaoct‐7‐ene) sulfonyl fluoride‐ter‐8‐bromo‐1H,1H,2H‐perfluorooct‐1‐ene] terpolymers containing various sulfonyl fluoride and brominated side groups. Yields higher than 70% were reached in all cases. The hydrolysis of the sulfonyl fluoride group into the ? SO₃Li function in the presence of lithium carbonate was quantitatively achieved without the content of VDF being affected, and so dehydrofluorination of the VDF base unit was avoided. These original terpolymers were then crosslinked via dangling bromine atoms in the presence of a peroxide/triallyl isocyanurate system, which produced films insoluble in organic solvents such as acetone and dimethylformamide (which totally dissolved uncured terpolymers). The acidification of ? SO₃Li into the ? SO₃H function enabled protonic membranes to be obtained. The thermal stabilities of the crosslinked materials were higher than those of the uncured terpolymers, and their electrochemical performances were investigated. According to the contents of the sulfonic acid side functions, the ion‐exchange capacities ranged from 0.6 to 1.5 mequiv of H⁺/g, whereas the water uptake and conductivities ranged from 5–26% (±11%) and from 0.5 to 6.0 mS/cm, respectively. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 4566–4578, 2006     

新型2-氧代-1,2,4-三唑并[3,2-d][1,5]苯并氧氮杂类稠杂环的合成

将取代色满酮(1)与芳肼反应生成的腙与HNCO发生[3+2]环加成反应,加成产物(2)经氧化得到偕偶氮异氰酸酯(3).化合物3在HBF4的催化下发生环化-重排反应,得到新颖的三环系2-氧代-1,2,4-三唑并[3,2-d][1,5]苯并氧氮杂化合物5a～5g.     

Catalytic carbonylation of potassiumN,2-dichlorobenzenesulfonamidate to sulfonyl isocyanate

Application of acetonitrile as a solvent in the catalytic carbonylation of potassiumN,2-dichlorobenzenesulfonamidate allowed to reduce the catalyst/substrate ratio and the CO pressure as compared to those used with chlorinated hydrocarbons.     

Cycloaddition reactions of 2,4-diphenyl-1,3-diazabuta-1,3-dienes with isocyanates and isothiocyanates

The cycloaddition reactions of 1-p-tolyl and 1-benzyl- 2,4-diphenyl-1,3-diazabuta-1,3-dienes with a variety of aryl and alkyl isocyanate and isothiocyanate are described. The reaction mechanism is also discussed.     

Trifluoromethanesulfonyl azide: an efficient reagent for the preparation of α-cyano-α-diazo carbonyls and an α-sulfonyl-α-diazo carbonyl

The reaction scope of trifluoromethanesulfonyl azide in diazo transfer reactions was extended to include the preparation of α-cyano-α-diazo-carbonyls, phenyl sulfonyl diazoacetophenone and diethyl diazomalonate in high yields. The effect of the bases used in the diazo transfer reactions were found to have a dramatic influence on the success of the reaction with pyridine being the base of choice.     

Bioisostere of Sulfonyl Moiety-The Synthesis of New ALS Inhibitors N-(Asymmetry Disubstituted Phosphoryl)-N'-(4,6-dimethoxypyrimidin-2-yl) Ureas

IntroductionAcetolactatesynthase(ALS)isthefirstcommonenzymeinthebiosyntheticpathwayforthebranched-chainaminoacidsvaline,leucineandisoleucine.Itisaveryeffectivetargetsiteforherbicidalaction,whichistheselectedmodeofactionasitisspecificforplantsanddoesnotaffectmammals.Sulfonylureaherbicidesareanewclassofherbicidesdiscoveredinthemid-l97O'sl.ItsmodeofactionhasbeenestablishedtobeinhibitorytowardALS2.Muchattentionhasbeenfocusedonthiskindofcompounds,sincetheyhaveexcellentactivity,ahighdegreeofseIe…     

PIXE法分析共聚物中痕量氯

四氟乙烯和全氟4-甲基-3,6-二氧杂-△~7辛基磺酰氟在溶剂氟里昂-113(F-113)中进行自由基引发聚合反应时,共聚物(T-O)是否有链转移,可以通过测定所得共聚物中的含氯量来得以证实。我们首次应用质子X萤光分析法(PIXE)进行分析。结果表明,共聚物中含氯量小于1ppm,F-113溶剂并未发生链转移。同时,我们测定了已证明有F-113参与链转移反应的F_(40)试样,含氯量高达700ppm。     

Nature of the active center in the cyclotrimerization of isocyanates catalyzed by the tertiary amine—α-oxide—protondonor system

The structure of the dimethylbenzylamine (DMBA)—phenylglyc idyl ether (PGE)—phenol complex was studied by IR and¹H NMR spectroscopy under various conditions of its formation. The active catalyst in the cyclotrimerization of isocyanates is a complex of composition DMBA : PGE : PhOH = 1 : 1 : 2, in which the oxygen atom of the zwitter-ion PhCH₂N⁺Me₂CH₂CH(O^–)CH₂OPh that forms after opening, of the epoxide cycle is bound to two phenol molecules by a very strong hydrogen bonds. In this complex, the oxygen atom of both the zwitter-ion and the phenolate anion can be catalytic centers. Two schemes of the cyclotrimerization of isocyanate in the presence of the aforementioned catalytic system are suggested, depending on whether the catalytic complex has time to form or not.For Part I, see Ref. 1.Deceased.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1662–1668, July, 1996.