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Updated: Jan 8, 2026
A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis
Published on: February 16, 2020
Enantioselective Intramolecular C-H Alkylation Catalyzed by a Nonsymmetric Chiral Cobalt Porphyrin
Christoph Buchelt1, Stefan Breitenlechner1, Julian Zuber1
1School of Natural Sciences, Department of Chemistry and Catalysis Research Center (CRC), Technische Universität München, Lichtenbergstr. 4, 85747 Garching, Germany.
Abstract:
Upon catalysis (1 mol %) by a chiral cobalt porphyrin, quinazolinones with a tethered diazo alkane precursor underwent an enantioselective C-H alkylation at carbon atom C4. Formation of five-, six-, and seven-membered rings was successfully accomplished (27 examples, 72-99% yield, 47-99% ee). Experimental and computational studies suggest that the catalyst recruits the substrates by two-point hydrogen bonding. After formation of a cobalt-entangled carbon-centered radical, a sequence of hydrogen abstraction and homolytic substitution is precisely orchestrated by the chiral confinement of the cobalt porphyrin.
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