Alkenyl organocopper reagent

The organocopper reagents react with alkyl-, alkenyl-, and aryl halides to give alkylated products. 

Organocopper reagents. Dialkenyl tellurides are readily transformed into copper reagents for conjugate addition, on reaction with CuCN-RLi. When the tellurides contain both alkyl and alkenyl groups they are also transformed into alkenylcuprates. 

A new method for the selective demethylation of alkyl methyl phosphates employs a mixture of dimethyl sulphide and methanesulphonic acid. Boron trifluoride etherate catalyses the regio- and stereo-specific alkenylation of phenolic ethers by diisopropyl prenyl or geranyl phosphates (84) in low to moderate yields. 2-(Diethoxyphosphinyl)-1,3-butadienes, e.g., (85), are cleaved by organocopper reagents in some cases this reaction is accompanied by alkylation and rearrangement to an allene structure. ... 

Another approach to bicyclic a-alkylidene y-lactones requires the preparation of iodinated alkynoate precursors that can undergo a radical cyclization (Equation 2) The resulting alkenyl iodide can be reduced with zinc to provide the trisubstituted alkene or can be further substituted with organocopper reagents to produce the desired y-lactones embedding a tetrasubstituted alkene. 

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