نتایج جستجو برای: substituted uea
تعداد نتایج: 39490 فیلتر نتایج به سال:
Highly fluorinated epoxides were polymerized under mild conditions regioregularly, which gave easy access to isotactic polymers by using optically pure epoxides.
A series of novel 3-(indol-1-yl)prop-1-yn-1-yl-substituted phthalazines and related azines was prepared via a concise pathway by palladium-catalyzed cross-coupling of appropriate halo-azines and N-propargylindoles. Some of the compounds exhibited significant antitumor activity in an in-vitro assay.
Non-concerted [2+2] and [4+2] cycloadditions between N,N-dimethylanilino-substituted 1,1,2,4,4-pentacyanobuta-1,3-diene and 4-ethynyl-N,N-dimethylaniline are controlled by solvent polarity and provide access to a highly functionalised 6,6-dicyanopentafulvene featuring an intense, low-energy charge-transfer band and to an unusual spirocyclic zwitterion, characterised by X-ray analysis.
Dirhodium catalyzed reactions of aryl-substituted tetrahydropyranone diazoacetoacetates produce ylide intermediates that unexpectedly yield two oxabicyclo[4.2.1]-nonane diastereoisomers, but a single diastereoisomer is formed by increasing the steric bulk of the aryl substituent.
A new total synthesis of the alkaloid variolin B is achieved by a selective and sequential palladium-mediated functionalization of a trihalo-substituted pyrido[30,20:4,5]pyrrolo[1,2-c]pyrimidine. This intermediate is obtained by a new heterocyclization reaction between an appropriate bromomethyl azaindole and N-tosylmethyl dichloroformimide. The methodology may be effective for the synthesis of...
A 2-diethanolamine boronyl substituted 1,3-diene has been synthesized in high yield and characterized spectroscopically as well as by X-ray crystallography. This diene has then subsequently been used in a number of fast, high yielding Diels-Alder/cross coupling reactions.
A strategy for synthesizing highly functionalized cyclohepta[b]indoles through a concise (4 + 3) cycloaddition-cyclization-elimination sequence is described. The cycloaddition features nitrogen-stabilized oxyallyl cations derived from epoxidations of N-aryl-N-sulfonyl-substituted allenamides, while the cyclization and elimination employed an intramolecular Grignard addition and a one-step Chuga...
BACKGROUND In chronic spontaneous urticaria (CSU) mast cell activation together with inflammatory changes in the skin are well documented and may play an important role in mechanisms of tissue oedema. OBJECTIVES To confirm and extend these observations by measuring microvascular markers, leucocytes and mast cell numbers in lesional and uninvolved skin and to compare findings with a control gr...
Invasion specificity of Eimeria stiedai sporozoites in cultured cells was examined. Intracellular sporozoites were observed in hepatobiliary epithelial cells, as early as 3 hours post inoculation (p.i.) but the infection rate was monitored for 6 hours. No intracellular parasites were found in rabbit parenchymal hepatocytes and rabbit kidney cells, even on prolonged culturing. In the hepatobilia...
AIMS Histopathological distinction of cystic jaw lesions, including odontogenic tumours, is challenging because their lining epithelia, which are basically stratified squamous epithelia, resemble each other, especially when they become hyperplastic from inflammatory reaction. The aim of this study was to seek practical measures to differentiate such lesions. METHODS AND RESULTS Nineteen surgi...
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