title: Cobalt-Catalyzed Oxidase C-H/N-H Alkyne Annulation: Mechanistic Insights and Access to Anticancer Agents.
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.
authors.affiliation: Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstraße 2, 37077, Göttingen, Germany.
authors.forename: Ruhuai
authors.initials: R
authors.lastname: Mei
authors.affiliation: Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstraße 2, 37077, Göttingen, Germany.
authors.forename: Hui
authors.initials: H
authors.lastname: Wang
authors.affiliation: Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstraße 2, 37077, Göttingen, Germany.
authors.forename: Svenja
authors.initials: S
authors.lastname: Warratz
authors.affiliation: Institute of Chemical Sciences, Heriot-Watt University, Edinburgh, EH14 4AS, UK. S.A.Macgregor@hw.ac.uk.
authors.forename: Stuart A
authors.identifier: 0000-0003-3454-6776
authors.initials: SA
authors.lastname: Macgregor
authors.affiliation: Institut für Organische und Biomolekulare Chemie, Georg-August-Universität Göttingen, Tammannstraße 2, 37077, Göttingen, Germany. Lutz.Ackermann@chemie.uni-goettingen.de.
authors.forename: Lutz
authors.identifier: 0000-0001-7034-8772
authors.initials: L
authors.lastname: Ackermann
mesh_terms: D000480:Alkynes / Q000737:chemistry*; D000970:Antineoplastic Agents / Q000138:chemical synthesis / Q000737:chemistry*; D002384:Catalysis; D003035:Cobalt; D056831:Coordination Complexes / Q000737:chemistry; D006576:Heterocyclic Compounds, 4 or More Rings / Q000138:chemical synthesis / Q000737:chemistry*; D007546:Isoquinolines / Q000138:chemical synthesis / Q000737:chemistry; D010088:Oxidoreductases / Q000737:chemistry; D011789:Quantum Theory; D013237:Stereoisomerism; D013816:Thermodynamics; D059004:Topoisomerase I Inhibitors / Q000138:chemical synthesis / Q000737:chemistry*
chemical_list: C000617876:21,22-dimethoxyrosettacin; D000480:Alkynes; D000970:Antineoplastic Agents; D056831:Coordination Complexes; D006576:Heterocyclic Compounds, 4 or More Rings; D007546:Isoquinolines; D059004:Topoisomerase I Inhibitors; D003035:Cobalt; D010088:Oxidoreductases
keywords: C−H activation; annulation; cobalt; density functional calculations; isoquinolones; oxidase