General nickel-catalyzed method for C-H bond alkynylation of heteroarenes through chelation assistance

TitleGeneral nickel-catalyzed method for C-H bond alkynylation of heteroarenes through chelation assistance
Publication TypeJournal Article
Year of Publication2017
AuthorsPunji, B, Khake, Smanmathapp, Soni, V, Gonnade, RGhanshyam
JournalChemistry - A European Journal
Volume23
Issue12
Pagination2907-2914
Date PublishedFEB
Abstract

A general nickel-catalyzed method for the alkynylation of heteroarenes through monodentate chelation assistance is described. Many heterocycles, including indoles, pyrroles, imidazoles and pyrazole, efficiently coupled with (triisopropylsilyl)alkynyl bromide, and synthetically important functional groups, such as halides, ether, nitrile, nitro were tolerated. Synthetic applicability of this Ni-catalyzed method is demonstrated by the removal of triisopropylsilyl (-SiiPr₃) group, and further functionalization into triazolyl, benzofuranyl and alkynyl arene derivatives. Preliminary mechanistic investigations on the alkynylation of indole suggest that the reaction proceeds through kinetically relevant C-H activation and follows the two-electron redox pathway. A catalytically competent Ni-species, [(Phen)₃Ni].NiBr₄ has been isolated and structurally characterized.

DOI10.1002/chem.201605306
Type of Journal (Indian or Foreign)

Foreign

Impact Factor (IF)

5.771

Divison category: 
Center for Material Characterization (CMC)
Organic Chemistry