نتایج جستجو برای: 5 tetrasubstituted imidazoles
تعداد نتایج: 1218724 فیلتر نتایج به سال:
two simple protocols for the synthesis of 1, 2, 4, 5- tetrasubstitutedimidazoles using nano-spa as a reusable, eco- friendly, inexpensive, and efficient catalyst are reported. short reaction times, high yields, scale-up and easy workup are the advantages of these protocols.
Two simple protocols for the synthesis of 1, 2, 4, 5- tetrasubstitutedimidazoles using nano-SPA as a reusable, eco- friendly, inexpensive, and efficient catalyst are reported. Short reaction times, high yields, scale-up and easy workup are the advantages of these protocols.
A series of tri- and tetra- substituted imidazoles were synthesized from benzyl, aldehyde and ammonium acetate in the presence of zeolite as an ecofriendly reusable catalyst under microwave irradiation in the absence of solvent. The yields are high to excellent and the use of microwave irradiation reduces reaction times to few minute.
The reaction of protected 4,5-diiodoimidazoles with (PhMe2CCH2)2CuLi regioselectively provides 5-cuprated imidazoles, which readily react with various electrophiles furnishing functionalized imidazoles in good yields; remarkably, these resulting mono-iodoimidazoles undergo again an iodine-copper exchange reaction in the presence of sensitive functional groups, like an aldehyde or a ketone.
The first examples of highly enantioselective Narasaka-Heck cyclizations are described. A SPINOL-derived P,N-ligand system enables Pd-catalyzed 5-exo cyclization of a range of oxime esters with sterically diverse trisubstituted alkenes to generate dihydropyrroles containing tetrasubstituted nitrogen-bearing stereocenters in 56 to 86% yield and 90 : 10 to 95 : 5 e.r. These processes are rare exa...
A survey of the pertinent literature reveals that aryl imidazoles have been found to possess a wide spectrum of biological activity such as antibacterial [1], antirheumatoid arthritis [2], antitubercular [3], antiviral [4], anti-inflammatory [5] and anticancer activities [6-8]. Specifically, it has been revealed from the literature that imidazoles fused with indole nucleus possess various biolo...
An alternative strategy for the synthesis of 1-aryl- and 1-alkyl-2-methylsulfanyl-4-(4-fluorophenyl)-5-(pyridin-4-yl)imidazoles as potential p38α mitogen-activated protein kinase inhibitors is reported. The regioselective N-substitution of the imidazole ring was achieved by treatment of α-aminoketones with different aryl or alkyl isothiocyanates. In contrast to previously published synthesis ro...
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