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
the synthesis of alkynylphosphine oxides based on the oxidative alkynylation of secondary phosphineoxides with copper acetylides was developed. Activation with molecular oxygen in the presence of either a mixture of 1,2-dimethylimidazole and triethylamine or N-methylimidazole alone enabled the formal umpolung of the poorly nucleophilic copper acetylides, which were coupled with phosphineoxides under
An original and user-friendly synthesis of alkynylphosphine-boranes, useful building blocks in organic synthesis, based on an oxidative P-alkynylation reaction with readily available copper acetylides is reported. The ability of a secondary phosphine protected with a borane to undergo oxidative coupling without oxidation of the P-moiety is demonstrated for the first time. The reaction, which proceeds at room temperature, is applicable to the preparation of enantioenriched and structurally complex alkynylphosphine-boranes.