نتایج جستجو برای: amidines
تعداد نتایج: 390 فیلتر نتایج به سال:
α,β-Unsaturated amidines can be synthesized in high yield by rhodium(II) carboxylate catalyzed 1,2-H shift following denitrogenation of α-diazo amidines. Using a large ligand and an electron-poor N-sulfonyl group results exclusive Z-selectivity excellent suppressing side reactions involving intramolecular oxygen transfer.
Certain aromatic amidines have been reported to be useful chemotherapeutic agents for the treatment of leishmaniasis, trypanosomiasis, and babesiasis (1). Pharmacological and clinical studies of these compounds have been handicapped by lack of suitable methods for the determination of aromatic amidines in plasma and urine. Recently Fuller (2) described a method which is based upon a reaction be...
Three amidines, N, N’-Diphénylbenzamidine (1), N-Cyclohexyl-N’-phényl-octamidine (2), N, N’diphényldodécamidine (3), were synthesized and investigated for their antioxidant activity using 2, 2-diphenyl-1picrylhydrazyl (DPPH) radical scavenging, ferric reducing antioxidant power (FRAP) and β-carotene/linoleic acid assays. The results indicated that amidines tested possess good antioxidant activi...
A Pd-catalyzed and ligand-free carbonylation/cycloaddition/decarboxylation cascade synthesis of sulfonyl amidines from sulfonyl azides and substituted amides at low CO pressure is reported. The reaction proceeds via an initial Pd-catalyzed carbonylative generation of sulfonyl isocyanates from sulfonyl azides, followed by a [2 + 2] cycloaddition with amides and subsequent decarboxylation, which ...
Mesoionic 4-trifluoroacetyl-1,3-oxazolium-5-olates (1), obtained from the reaction of N-acyl-N-alkylglycines (2) with trifluoroacetic anhydride, react with amidines to give 5-trifluoroacetylimidazoles (3) in moderate yield. The novel ring transformations of 1 into 3 occur via an initial attack of amidines on the C-2 position of the ring.
Cu-catalyzed aerobic oxidative three-component coupling of a terminal alkyne, secondary amine, and sulfonamide enables efficient synthesis of amidines. The use of Cu(OTf)2 (5 mol %) produces amidines selectively without Glaser-Hay alkyne homocoupling products. Preliminary studies suggest that the reaction pathway involves initial oxidative coupling of the terminal alkyne with the secondary amin...
An immense effort has been made to develop efficient strategies for the direct functionalization of C H bonds using transition-metal catalysis. For the most part, ruthenium-, rhodium-, and palladium-based catalysts have been applied to effect either C C or C Het (Het= heteroatom) bond formation by replacement of a C H bond. Few examples have been described that employ copper as catalysts, which...
Aromatic diamidines represent a class of DNA minor groove-binding ligands that exhibit high levels of antiparasitic activity. Since the chemotherapy for Chagas' disease is still an unsolved problem and previous reports on diamidines and related analogues show that they have high levels of activity against Trypanosoma cruzi infection both in vitro and in vivo, our present aim was to evaluate the...
Condensation reactions of carboxylic acids and anilines in the presence of polyphosphoric acid trimethylsilyl ester (PPSE) afforded a range of sterically demanding N,N'-bis(aryl)amidines, RN{C(R')}N(H)R [R = Mes (Mes = 2,4,6-trimethylphenyl), R' = Cy (Cy = cyclohexyl) L¹H; R = Dipp (Dipp = 2,6-diisopropylphenyl), R' = Cy L²H; R = Mes, R' = Ph L³H; R = Dipp, R' = Ph L⁴H; R = Mes, R' = Dmp (Dmp =...
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