Diverse Reactivity of 9‐Fluorene Propargylic Alcohol and 1,3‐Dicarbonyls with Bronsted and Lewis Acid Catalysts: Synthesis of Spiro, Conjugated, and 9‐Ethynyl Fluorene Derivatives
A TFA‐catalyzed reaction of fluorene propargylic alcohol with 1,3‐dicarbonyls as nucleophiles, resulting in highly functionalized conjugated diene‐diones appended and propargyl‐substituted 1,3‐dicarbonyl derivatives of fluorenone, has been developed. A plausible mechanism for forming title compounds via allene and propargyl carbocation intermediates has been proposed. On the other hand, the reaction under Lewis acid conditions (BF 3 OEt 2 ) afforded an unusual spirocyclic product, and a plausible mechanism is provided. The scope and synthetic utility of the synthesized products by reduction and base‐promoted cyclization have also been investigated. Spectroscopic data and single‐crystal XRD of the compounds have been utilized to determine the structure of the products.
Authors
- Ponnusamy Shanmugam (ORCID: https://orcid.org/0000-0003-0411-1982)
- Aravamudhan Subhashini (ORCID: https://orcid.org/0009-0001-5621-4775)
Institutions
- Central Leather Research Institute (IN)
Publication Details
- Journal
- European Journal of Organic Chemistry
- Published
- 2025-12-12
- DOI
- https://doi.org/10.1002/ejoc.202500783
- Primary Topic
- Catalytic Alkyne Reactions
- Type
- article
- Field-Weighted Citation Impact
- 0.00
Funders
- Department of Science and Technology, Ministry of Science and Technology, India
- Indian Institute of Technology Madras
- Academy of Scientific and Innovative Research
- Central Leather Research Institute