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Copper-catalyzed oxidative cross-dehydrogenative coupling of 2H-chromenes and terminal alkynes.

ABSTRACT: An efficient copper-catalyzed cross-dehydrogenative coupling of 2H-chromenes and terminal alkynes mediated by DDQ has been established. A protic additive, EtOH, proved to be crucial for harmonizing the oxidation with a subsequent alkynylation step by retaining the oxidation state of an oxocarbenium ion in the form of acetal. The CDC reaction exhibits a good substrate scope, with a range of terminal aryl- and alkyl alkynes being well tolerated. The copper-catalyzed alkynylation of 2H-chromene acetals with terminal alkynes was also explored.

SUBMITTER: Yang F

PROVIDER: S-EPMC6051884 | biostudies-literature | 2018 Jul

REPOSITORIES: biostudies-literature

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Copper-catalyzed oxidative cross-dehydrogenative coupling of 2H-chromenes and terminal alkynes.

Yang Fei F Li Yangshan Y Floreancig Paul E PE Li Xiaoyan X Liu Lei L

Organic & biomolecular chemistry 20180701 28

An efficient copper-catalyzed cross-dehydrogenative coupling of 2H-chromenes and terminal alkynes mediated by DDQ has been established. A protic additive, EtOH, proved to be crucial for harmonizing the oxidation with a subsequent alkynylation step by retaining the oxidation state of an oxocarbenium ion in the form of acetal. The CDC reaction exhibits a good substrate scope, with a range of terminal aryl- and alkyl alkynes being well tolerated. The copper-catalyzed alkynylation of 2H-chromene ace ...[more]

PMID: 29963678

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