Alkynes organocopper reagents

For the addition of organocopper reagents to alkynes and conjugated dienes, see 15-23. 

When the CuBr-SMe2 complex is used in preparing the organocopper reagent, and Me2S is a cosolvent in the addition, higher yields may be achieved. Under such conditions even the otherwise unreactive methylcopper adds to terminal alkynes to generate 2-methyl-susbtituted alkenylcopper derivatives.520... 

The conjugate addition of organocopper reagents to ot,(3-alkynic esters, ketones, aldehydes and acids is a useful method for the preparation of various tri- and tetra-substituted alkenes,87 although addition to aldehydes is less common.88 Use of a vinylcuprate results in the formation of a conjugated dienone, which further highlights the importance of this methodology (equation 43 ).87... 

I. B. Campbell, The Sonogashira Cu-Pd-Catalyzed Alkyne Coupling Reactions, in Organocopper Reagents A Practical Approach (R. J. K. Taylor, Ed.), 217, Oxford University Press, Oxford, U. K., 1994. 

Copper(i) catalysis of the addition of organomagnesium compounds to alkynes has been observed, but stoichiometric organocopper reagents, derived from organomagnesium compounds, are more effective in the absence of other activating features [4],... 

The NMR spectrum of an intermediate similar to 148 has been reported." For the addition of organocopper reagents to alkynes and conjugated dienes, see 15-22. 

Scheme 7-15 Internal carbocupration of an alkyne by a primary organocopper reagent.

Campbell IB (1994) The sonogashira Cu-Pd-catalyzed alkyne coupling reaction. In Organocopper Reagents. Oxford Oxford University Press, 217. 

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