Organohalides transition-metal halides

Little is known about the oxidative addition of organohalides to early transition metal atoms. Nevertheless, macroscale amounts of solvated transition metal halides in lower valency states have been obtained. Re yields interesting clusters in reactions with 1,2-dibromoethane and oxalyl chloride ... 

It follows that where organohalides are used in the preparation of organo metal complexes, an excess may cause low yields. There are a few examples where alkyl halides add to transition metal complexes (see pp. 251, 264). 

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