Abstract
Cp*-free cobalt-catalyzed alkyne annulations by C-H/N-H functionalizations were accomplished with molecular O2 as the sole oxidant. The user-friendly oxidase strategy proved viable with various internal and terminal alkynes through kinetically relevant C-H cobaltation, providing among others step-economical access to the anticancer topoisomerase-I inhibitor 21,22-dimethoxyrosettacin. DFT calculations suggest that electronic effects control the regioselectivity of the alkyne insertion step.
Keywords:
C−H activation; annulation; cobalt; density functional calculations; isoquinolones; oxidase.
© 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Alkynes / chemistry*
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Antineoplastic Agents / chemical synthesis
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Antineoplastic Agents / chemistry*
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Catalysis
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Cobalt*
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Coordination Complexes / chemistry
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Heterocyclic Compounds, 4 or More Rings / chemical synthesis
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Heterocyclic Compounds, 4 or More Rings / chemistry*
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Isoquinolines / chemical synthesis
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Isoquinolines / chemistry
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Oxidoreductases / chemistry
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Quantum Theory
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Stereoisomerism
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Thermodynamics
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Topoisomerase I Inhibitors / chemical synthesis
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Topoisomerase I Inhibitors / chemistry*
Substances
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21,22-dimethoxyrosettacin
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Alkynes
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Antineoplastic Agents
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Coordination Complexes
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Heterocyclic Compounds, 4 or More Rings
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Isoquinolines
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Topoisomerase I Inhibitors
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Cobalt
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Oxidoreductases