نتایج جستجو برای: bis spiro oxindolopyrrolizidinespyrrolidines
تعداد نتایج: 49983 فیلتر نتایج به سال:
The crystal structures of the new compounds spiro[cyclohexane-1,3’-indol]-2’(1’H)-one (1), (rel-1R,2S)-spiro[bicyclo[2.2.1] heptane-2,3’-indol]-2’(1’H)-one (2) and spiro[indole-3,2’-tricyclo[3.3.1.1]decan]-2(1H)-one (3) have been determined by low temperature single crystal X-ray diffraction. The effects of substitution on the hydrogen bonding pattern is compared between all three compounds.
Beryllium succinate dihydrate [Be(C4H4O4)](H2O)2 is formed in the reaction of equimolar quantities of beryllium sulfate, succinic acid and barium hydroxide in aqueous solution at pH 3.2. Sodium, potassium, and ammonium bis(succinato)beryllates M2[Be(C4H4O4)2] are obtained using the same reagents in the molar ratio 1:2:1 and adjusting the pH to 6.3-6.5 with NaOH, KOH or concentrated aqueous ammo...
Reaction of Meldrum's acid with 3,4-bis(chloromethyl)-2,5-dimethylthiophene (1) or 3,4-bis(bromomethyl)-2,5-dimethylthiophene (2) produces the kinetically favored C,O-dialkylation product, 1,3,7,7-tetramethyl-4H,10H-6,8,9-trioxa-2-thiabenz[f]azulen-5-one (4). Recrystallization of 4 from refluxing methanol results in the methanolysis product 5-(4-methoxymethyl-2,5-dimethylthiophen-3-ylmethyl)-2,...
The concise synthesis of spiro-cyclopropane compounds via the dearomatization of indole derivatives.
A concise synthesis of spiro-cyclopropane compounds from indole derivatives and sulfur ylides has been developed via a dearomatization strategy. Moreover, the spiro-cyclopropane compounds could be conveniently transformed to rearomatized indole derivatives in the presence of acids.
A stable enol from a 6-substituted benzanthrone and its unexpected behaviour under acidic conditions
Treatment of benzanthrone (1) with biphenyl-2-yl lithium leads to the surprisingly stable enol 4, which is converted by dehydrogenation into the benzanthrone derivative 7. Under acidic conditions 4 isomerises to the spiro compound 11 and the bicyclo[4.3.1]decane derivative 12. Furthermore, the formation of 7 and the hydrogenated compound 13 is observed. A mechanism for the formation of the reac...
[2+2] Cycloadditions of methylene exo-glycal derivatives with chlorosulfonyl isocyanate and dichloroketene were studied in detail, investigating the effect carbohydrate moiety, protecting groups as well reaction temperature on yields transformations. These reactions gave new anomeric spiro-β-lactam spiro-cyclobutanone derivatives, whose structure was established by 1D 2D NMR MS experiments. The...
The isomerism of the polyspirodienone derivatives of the large-ring p-fertbutylcalix[n]arenes (n=5,6,8) is analyzed. Monoand polyspirodienone calix[n]arene derivatives were prepared by mild oxidation of the respective calix[n]arenes and the obtained products were characterized. Reactions of the monospirodienone derivatives with hydrazines and their rearrangements to xanthenocalixarenes are desc...
Spiro-N,N-ketal 5, consisting of a phthaloperine heterocyclic ring and a naphtha[1,8-ef][1,4]diazepine ring, was obtained along with spiro-N,N-ketal 2 via 2,2-condensation in the reaction of ninhydrin with naphthalene-1,8-diamine. Their molecular structures were elucidated by X-ray crystal structural analysis. Aside from these spiro compounds, the diazapleiadiene compound 3 formed by 1,2-conde...
To construct high-performance organoboron-based blue emitters for electroluminescent (EL) devices, two diboron complexes have been synthesized through the chelation of 2-(1-phenyl-1H-benzo[d]imidazole-2-yl)phenol or 2-(2-pyridyl)phenol ligands with both boron atoms of the 9,10-diboraanthracene group. These complexes exhibit bright blue emissions in solution and in solid films with fluorescence ...
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