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Updated: Jan 15, 2026

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
Electro-carbo-cyclization of alkyne-, alkene-, and nitrile-tethered α-halocarbonyls
Subhadeep Ghosh1,2, Sumit Biswas1, Indrajit Das1,2
1CSIR-Indian Institute of Chemical Biology, Organic and Medicinal Chemistry Division, 4, Raja S. C. Mullick Road, Kolkata 700032, India. indrajit@iicb.res.in.
Abstract:
The electrochemical dehalogenative carbo-cyclization of acyclic precursors provides an efficient method for synthesizing various heterocycles. Typically, C(sp2) aryl radicals undergo intramolecular carbo-cyclization with unsaturated functional groups. In this report, we present, for the first time, a carbo-cyclization involving tertiary C(sp3) radicals reacting with alkynes, alkenes, and nitriles in an undivided cell. This leads to the synthesis of both deuterated and non-deuterated 3,4-dihydroquinolin-2-ones and quinoline-2,4-diones in good yields. The proposed mechanism is supported by the isolation of a 4-benzylidene intermediate.
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