Room-Temperature Direct Alkynylation of Arenes with Copper Acetylides
作者:Cédric Theunissen、Gwilherm Evano
DOI:10.1021/ol502030y
日期:2014.9.5
C–H bond in azoles and polyhalogenated arenes can be smoothly activated by copper acetylides to give the corresponding alkynylated (hetero)arenes by simple reaction at room temperature in the presence of phenanthroline and lithium tert-butoxide under an oxygen atmosphere. These stable, unreactive, and readily available polymers act as especially efficient and practical reagents for the introduction
Copper as a Powerful Catalyst in the Direct Alkynylation of Azoles
作者:François Besselièvre、Sandrine Piguel
DOI:10.1002/anie.200904776
日期:2009.12.7
Copper‐bottomed catalysis! The direct alkynylation of azolesthrough a copper‐based CH bond activation, using alkynylbromides as the coupling partner, has been developed (see scheme). The method is very rapid, is functional‐group tolerant, and provides a straightforward entry to diverse alkynyl heterocycles that is complementary to the Sonogashira reaction.
The direct alkynylation reaction of 1,3,4-oxadiazoles with alkynyl bromides efficiently proceeds in the presence of a copper catalyst at room temperature to create the corresponding heteroaryl−alkynyl linkage in good yields. This direct coupling provides a rapid and convergent access to oxadiazole core π-conjugated systems.
The simplest coupling: Copper‐mediated direct oxidative cross‐coupling of 1,3,4‐oxadiazoles and oxazoles with terminal alkynes proceeds through cleavage of sp2 CH and sp CH bonds to furnish the corresponding alkynylazoles in good yields. The reaction is tolerant toward various substitution patterns of substrates and allows the facile construction of azole‐core π‐conjugated systems.