Organocopper compound alkynylation

As a last example of an uncatalyzed C,C coupling of a neutral organocopper compound Figure 16.9 depicts the alkynylation of a copper acetylide with a bromoalkyne which is easily accessible via bromination of a terminal alkyne ... 

Arylations, Alkenylations and Alkynylations of Neutral Organocopper Compounds II... 

Other examples of coupling between alkynyl halides and organocopper compounds can be found in Reference 559. 

Ebert, G. W., RIeke, R. D. Preparation of aryl, alkynyl, and vinyl organocopper compounds by the oxidative addition of zerovalent copper to carbon-halogen bonds. J. Org. Chem. 1988, 53,4482-4488. 

We have found that alkynylsilanes are smoothly converted into alkynylcopper compounds by treatment with CuCl in l,3-dimethyl-2-imidazohdinone (DMI) the copper reagents can be isolated in good yields [563]. This study was the first example of preparation and isolation of organocopper compounds by use of organosilicon reagents. The Si-Cu transmetalation is applicable to the synthesis of alkynyl ketones by Cu-catalyzed alkynylation of acid chlorides (Scheme 10.217). We have also shown that a Cu-mediated system is effective in the cross-coupling reaction between arylsilanes or heteroarylsilanes and aryl hahdes [564]. 

Cross-coupling with Organocopper Reagents. HexasUylbi-cyclo[2.2.2]octan-l-yl copper, prepared from tbe treatment of hexasilylbicyclo[2.2.2]octan-l-yl lithium with copper(T) iodide in THF, reacts with (iodoethynyl)trimethylsilane (eq 6) in the presence of pyridine to afford the alkynyl-substituted polysilacage compound. ... 

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