Activation of Reducing Agents. Sodium Hydride Containing Complex Reducing Agents. 15. Reduction and Selective Reduction of Organic Halides

Article abstract of DOI:10.1021/jo00320a009

The reduction of alkyl and vinyl halides with a reducing system composed of NaH, alkoxides, and metal salts ("complex reducing agents", CRA) has been investigated.The reagent system efficiently converts primary, secondary, and tertiary alkyl iodides, bromides, and chlorides to the corresponding hydrocarbons.Alkyl tosylates are less readily attacked, and fluorides are inert.Benzyl, allyl, and vinyl halides are also reduced.The latter react stereospecifically without double bond isomerization.Selective reductions of mixtures of alkyl halides are possible with eitherNi CRA or Zn CRA, and the reagents are inert toward a number of other functional groups, allowing selective reductions to be achieved.Finally, the reduction may be achieved by using catalytic amounts of nickel salts.Possible structures for the complex reducing agents are discussed, as well as suggested mechanisms for halide reductions.