Investigations on the Reactivity of Fascaplysin, Part II, General Stability Considerations and Products Formed with Nucleophiles

Fretz, Heinz; Ucci-Stoll, Katharina; Hug, P.; Schoepfer, Joseph; Lang, Marc

doi:10.1002/1522-2675(20010418)84:4<867::aid-hlca867>3.0.co;2-a

Cited by 12 publications

(16 citation statements)

References 6 publications

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“…To our delight, even with smallest nucleophile, target amide 3 n was exclusively produced in good yield without byproduct of imine formed via competitive reaction between amino and benzoyl groups. Bearing in mind that the benzoyl functionality of fascaplysin is much active, this result clearly indicates the feasibility of our methodology to form amide with excellent efficiency and chemoselectivity.…”

Section: Resultsmentioning

confidence: 52%

Efficient and Chemoselective Amidation of β‐Carboline Carboxylic Acids

Lin

Liang

et al. 2019

ChemistrySelect

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Section: Resultsmentioning

confidence: 52%

Efficient and Chemoselective Amidation of β‐Carboline Carboxylic Acids

Lin

Liang

et al. 2019

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“…Previously zwitter-ionic β-carboline 26 was obtained from fascaplysin that was treated with aqueous solution of NaOH or 30% NH 4 OH [39]. After optimization of the reaction conditions 14-bromoreticulatate ( 10 ) and its dibromo analog ( 27 , not isolated from marine organisms) were obtained from compounds 3 and 5 in DMF at r.t. with 86% and 80% yields, respectively (Scheme 3).…”

Section: Resultsmentioning

confidence: 99%

Total Syntheses and Preliminary Biological Evaluation of Brominated Fascaplysin and Reticulatine Alkaloids and Their Analogues

et al. 2019

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A simple approach toward the synthesis of the marine sponge derived pigment fascaplysin was used to obtain the marine alkaloids 3-bromofascaplysin and 3,10-dibromofascaplysin. These compounds were used for first syntheses of the alkaloids 14-bromoreticulatate and 14-bromoreticulatine. Preliminary bioassays showed that 14-bromoreticulatine has a selective antibiotic (to Pseudomonas aeruginosa) activity and reveals cytotoxicity toward human melanoma, colon, and prostate cancer cells. 3,10-Dibromofascaplysin was able to target metabolic activity of the prostate cancer cells, without disrupting cell membrane’s integrity and had a wide therapeutic window amongst the fascaplysin alkaloids.

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“…An analogous opening of the fi ve-membered ring was earlier described in the literature. It was shown that fascaplysin (V) at treatment with alkali formed zwitter-ion VI [4] (Scheme 3).…”

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confidence: 99%

Reaction of indigo malonic ester with dimethyl sulfate

Andin

Sokolov

2012

Russ J Org Chem

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Indigo malonic ester (I), the product of indigo condensation with malonic ester, a representative of the class of 6,13-dioxopyrido[1,2-a;3,4-b]diindoles, has been known since the beginning of the previous century; it has been fi rst obtained in 1926 alongside the product of indigo condensation with phenylacetic acid and its N-acyl derivatives [1]. The chemical properties of these compounds were not practically further examined. Yet the pyrido[1,2-a;3,4-b]diindole system is the structural skeleton of a series of marine alkaloids of a high biological action, e.g., fascaplysin from the sponge Fascaplysinopsis sp. [2].We examined the reaction of indigo malonic ester (I) with dimethyl sulfate. The reaction was carried out in DMF in the presence of sodium hydride. It was initially presumed that the indigo malonic ester being an ambidente nucleophile would form a mixture of N-and O-methylation products. However unexpectedly alongside the product of the N-methylation II we isolated a substituted pyrido [3,4-b]indole III (Scheme 1).We failed to convert fully compound II into III, and increasing the reaction duration and the excess of dimethyl sulfate did not affect the yield of compound III.The sequence of transformations leading to compound III may be rationalize as follows. Evidently fi rst the ambidente anion originating from initial pyridodiindole I at the action of sodium hydride suffers the O-methylation. The product of the О-methylation in the presence of excess dimethyl sulfate is methylated again at the nitrogen Scheme 1.

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Investigations on the Reactivity of Fascaplysin, Part II, General Stability Considerations and Products Formed with Nucleophiles

Cited by 12 publications

References 6 publications

Efficient and Chemoselective Amidation of β‐Carboline Carboxylic Acids

Efficient and Chemoselective Amidation of β‐Carboline Carboxylic Acids

Total Syntheses and Preliminary Biological Evaluation of Brominated Fascaplysin and Reticulatine Alkaloids and Their Analogues

Reaction of indigo malonic ester with dimethyl sulfate

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