نتایج جستجو برای: intermediate c ring
تعداد نتایج: 1259952 فیلتر نتایج به سال:
Herein we report the formation and interesting reactivity of several azepino[4,5-b]indole heterocycles. Initially, a key intramolecular Heck reaction is used to efficiently create the azepino[4,5-b]indole seven membered ring containing an exocyclic double bond. Treatment of the olefin with ozone results in an unprecedented secondary reaction of the Criegee intermediate, through intramolecular o...
In the course of our studies on the regioselective carbon-oxygen bond cleavage of the benzylidene acetal group of hexopyranosides with a reducing agent, we found that a combination of a Lewis acid and a reducing agent triggered a ring-opening reaction of the pyranose ring of methyl α-D-allopyranosides. The formation of an acyclic boronate ester by the attachment of a hydride ion at C-1 indicate...
The marine ascidian Clavelina cylindrica produces a series of interesting tricyclic quinolizidine and indolizidine alkaloids that show toxicity in a brine shrimp assay.1 Cylindricines A (1), C (2), D (3), E (4), and F (5) differ only in the functionality of the methylene substituent in the fivemembered ring. Interestingly, cylindricines A and B (7) interconvert simply upon standing in solution,...
A review paper on Au(III) cyclometallated compounds with 2-arylpyridines (2-phenylpyridine, 2-benzylpyridine, 2-benzoylpyridine, 2-phenoxypyridine, 2-phenylsulfanylpyridine, 2-anilinopyridine, 2-(naphth-2-yl)pyridine, 2-(9,9-dialkylfluoren-2-yl)pyridines, 2-(dibenzofuran-4-yl)pyridine, and their derivatives) analogues (2-arylquinolines, 1- 3-arylisoquinolines, 7,8-benzoquinoline), 113 reference...
Substituted pyrroles may be synthesized from selected 1,2-pyridazines through a reductive ring contraction involving the addition of four electrons and four protons. Our density functional theory computations of this reaction mechanism show that the first reduction event must be preceded by the uptake of one proton by 1,2-pyridazine and that the reaction proceeds through a 2e(-)/3H(+)-bearing i...
HIE-124 is the new member of ultra-short acting hypnotics drug family. In this research, thiadiazole can act as the bio-isosteric replacement of thiazole in synthesized compounds as HIE-124 derivatives. HIE-124 drug, in which the heterocyclic thiazole ring replaced to thiadiazole, will be presented. Thiadiazolodiazepines were synthesized by a two-step reaction starting from the amino thiadiazol...
Tetracyclines are aromatic polyketides biosynthesized by bacterial type II polyketide synthases. The amidated tetracycline backbone is biosynthesized by the minimal polyketide synthases and an amidotransferase homologue OxyD. Biosynthesis of the key intermediate 6-methylpretetramid requires two early tailoring steps, which are cyclization of the linearly fused tetracyclic scaffold and regiosele...
<p>For a completely regular Hausdorff topological space X, let C(X, C) be the ring of complex-valued continuous functions on C ∗ (X, its subring bounded functions, and Σ(X, denote collection all rings that lie between C). We show there is natural correlation absolutely convex ideals/ prime ideals/maximal ideals/z-ideals/z ◦ -ideals in P(X, their real-valued counterparts ∩ C(X). These corr...
Substituted 2, 4- diphenyl quinolines were synthesized by a multicomponent domino reaction of anilines, aldehydes and terminal aryl alkynes. The synthetic pathway involves the formation of an imine, followed by the intermolecular addition of an alkyne to the imine. This intermediate immediately undergoes ring closure and oxidative aromatization. The reaction is catalyzed by natural kaolin, a st...
نمودار تعداد نتایج جستجو در هر سال
با کلیک روی نمودار نتایج را به سال انتشار فیلتر کنید