ArticleOrganic letters2018
Tin-Free Access to the ABC Core of the Calyciphylline A Alkaloids and Unexpected Formation of a D-Ring-Contracted Tetracyclic Core.
Article in Organic letters, 2018. The graph could read no effect estimate from its abstract, so it casts no vote on the map. An erratum has been issued. Cited by 3 papers.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
3 citing papers in PubMed.
- The Latest Progress in the Chemistry ofMolecules (Basel, Switzerland) · 2024Review
- Synthesis of the ABC Ring of Calyciphylline A-Type Alkaloids by a Stereocontrolled Aldol Cyclization: Formal Synthesis of (±)-Himalensine A.The Journal of organic chemistry · 2022Article
- Synthetic and Computational Study of Tin-Free Reductive Tandem Cyclizations of Neutral Aminyl Radicals.Organic letters · 2018Article
Corrections and comments
- Erratum issued
Authors and funding
5 authors.
Funding
Abstract
A tin-free strategy for the successful cyclization of a variety of internal alkyne-containing N-chloroamine precursors to the ABC core via cyclization of a neutral aminyl radical is established. Deuterium labeling experiments confirm that the solvent is the primary source of the final H atom in the cyclization cascade. These conditions enabled a streamlined route to a β-ketoester intermediate poised for intramolecular Knoevenagel condensation to construct the seven-membered D-ring of calyciphylline A alkaloids. However, exposure to CsF in t-BuOH at elevated temperatures led to an unexpected decarboxylation to form a D-ring-contracted tetracyclic core.
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Registered trials
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