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Zav’yalov, S. I.; Ezhova, G. I.; Kravchenko, N. E.; Kulikova, L. B.; Дорофеева, О. В.; Rumyantseva, E. E.; Zavozin, A. G.

doi:10.1023/a:1026355105151

Cited by 7 publications

(3 citation statements)

References 12 publications

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“…39 Initially, we focused on the direct addition of transmetallated derivatives of triazone 27 (Scheme 2, metal = Li, Mg, Cu, Ce, Zn) to the bicyclic C5-ester (+)-21. Unfortunately, these attempts were plagued by either lack of reactivity, the formation of byproducts associated with metal-halogen exchange, double addition, or competing decomposition pathways.…”

Section: Total Synthesis Of the Agelastatin Alkaloidsmentioning

confidence: 99%

Total Synthesis of All (–)‐Agelastatin Alkaloids

and

Han

2012

Asymmetric Synthesis II

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The pyrrole-imidazole family of marine alkaloids, derived from linear clathrodin-like precursors, constitutes a diverse array of structurally complex natural products. The bioactive agelastatins are members of this family that possess a tetracyclic molecular framework incorporating C4-C8 and C7-N12 bond connectivities. We provide a hypothesis for the formation of the unique agelastatin architecture that maximally exploits the intrinsic chemistry of plausible biosynthetic precursors. We report the concise enantioselective total syntheses of all known agelastatin alkaloids including the first total syntheses of agelastatins C, D, E, and F. Our gram-scale chemical synthesis of agelastatin A was inspired by our hypothesis for the biogenesis of the cyclopentane C-ring and required the development of new transformations including an imidazolone-forming annulation reaction and a carbohydroxylative trapping of imidazolones.

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Section: Total Synthesis Of the Agelastatin Alkaloidsmentioning

confidence: 99%

Total Synthesis of All (–)‐Agelastatin Alkaloids

and

Han

2012

Asymmetric Synthesis II

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“…Among the privileged core motifs, the naturally occurring heterocycle uracil (compound 1 , Figure 1) occupies a preeminent position, due to its innate chemical structure—a stable six‐membered 2,4‐pyrimidindione ring with a prevalence of the lactam tautomeric form—responsible for it to establish key gene‐related H‐bond connections [3] . In addition, uracil has proven to be extremely inclined toward chemical modification, especially at the N1, N3, C5, and C6 positions [4] . Accordingly, a wide array of uracil‐based molecules has been accessed so far, exhibiting as many diverse biological activities ranging from antiviral and anti‐tumor to herbicidal, bactericidal, and anti‐malarial action, as testified by the outstanding number of uracil‐founded drugs approved worldwide (Figure 1).…”

Section: Introductionmentioning

confidence: 99%

Unlocking Access to Enantiopure Fused Uracils by Chemodivergent [4+2] Cross‐Cycloadditions: DFT‐Supported Homo‐Synergistic Organocatalytic Approach

et al. 2020

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The discovery of chemical methods enabling the construction of carbocycle-fused uracils whiche mbody at hree-dimensional and functional-group-richa rchitecture is au seful tool in medicinal chemistry oriented synthesis.I nt his work, an unprecedented amine-catalyzed [4+ +2] cross-cycloaddition is documented;i ti nvolves remotely enolizable 6methyluracil-5-carbaldehydes and b-aryl enals,a nd chemoselectively produces two novel bicyclic and tricyclic fused uracil chemotypes in good yields with am aximum level of enantiocontrol. In-depth mechanistic investigations and control experiments support an intriguing homo-synergistic organocatalytic approach,w here the same amine organocatalyst concomitantly engages both aldehyde partners in as tepwise eliminative [4+ +2] cycloaddition, whose vinylogous iminium ion intermediate product mayd iverge-depending upon conditions-to either bicyclic targets by hydrolysis or tricyclic products by as econd homo-synergistic trienamine-mediated stepwise [4+ +2] cycloaddition.

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“…Unsubstituted uracil reacts smoothly in the Mannich reaction at the C-5 atom, forming the corresponding aminomethyl derivative [6]. However, blockade of this nucleophilic center produces cardinal changes in the direction of the reaction in favor of nitrogen atoms.…”

mentioning

confidence: 99%