Copper- and phosphine-free nickel(II)-catalyzed method for C-H bond alkynylation of benzothiazoles and related azoles

TitleCopper- and phosphine-free nickel(II)-catalyzed method for C-H bond alkynylation of benzothiazoles and related azoles
Publication TypeJournal Article
Year of Publication2018
AuthorsPatel, UN, Punji, B
JournalAsian Journal of Organic Chemistry
Volume7
Issue7
Pagination1390-1395
Date PublishedJUL
ISSN2193-5807
Keywordsalkynylation, azoles, C-H activation, heterocycles, Nickel
Abstract

A phosphine-free nickel(II)-catalyzed method for the C(2)-H bond alkynylation of (benzo)thiazoles, (benz)imidazoles, and oxazoles is described. Well-defined and air-stable (Phen)NiCl2 catalyst efficiently catalyzes the coupling of diverse azoles with alkynyl bromides without the use of a copper co-catalyst, and the method tolerates synthetically important functional groups. Preliminary mechanistic studies on this Ni-II-catalyzed alkynylation emphasize the homogeneous nature of the catalyst, and rule out a radical manifold for the reaction. The synthetic utility of this Ni-catalyzed method is demonstrated by further functionalizing the alkynylated benzothiazoles to 3-methyl-2-(alkynyl)benzo[d]thiazolium salts that are known DNA cleaving agents.

DOI10.1002/ajoc.201800243
Type of Journal (Indian or Foreign)

Foreign

Impact Factor (IF)

2.788

Divison category: 
Chemical Engineering & Process Development