RZnX reagent

Generally, organocopper compounds can be prepared by transmetallation between copper salts and organometallic reagents such as RLi, RMgX, and RZnX.53,53a,53b Copper alkynides can be obtained by reaction of terminal alkynes... 

Organoaluminum reagents have also been employed for alkylative rearrangement, but use of Grignard reagents permits greater flexibility. Reagents of the type RLi or RZnX are either ineffective or less satisfactory. 

There has only been one new report of a substitution without cleavage and this involves nucleophilic substitution of the benzotriazolyl group at C-2 of a 1,3-dioxolane by an organozinc reagent giving the substituted product (Equation 13) <2000JOC1886>. The RZnX is produced in situ by reaction of RMgX and ZnCU or RBr and zinc. 

A major part of this chapter will show the synthetic applications of these transmetallation reactions for the perfonnancc of cross-coupling reactions. After a short description of the methods of preparation of organozinc halides (RZnX) and diorganozincs (R2Zn), the utility of these reagents for forming new carbon-carbon bonds will be presented. Emphasis will be... 

The reagent is described as inexpensive, readily prepared and nonpyrophoric, but air-sensitive. Sodium dispersed on titanium dioxide in a similar way has been used to reduce zinc chloride to active zinc for reaction with RX to give RZnX. This method produces fewer by-products from Wurtz coupling.18... 

Organozinc compounds of the types RZnX and R2Zn are known, whereas except for BunCdCl40 only R2Cd compounds have been isolated. The constitution of RMX in solution has presented a-problem similar-to that for Grignard reagents. Spectroscopic studies400 show that RMX species predominate in ethers, e.g.,... 

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