Copper compounds dppe

Finally, some orgatiocopper compounds undergo diarge disproporLionation under die influence of ligands dial bind strongly to copper. Treatment of mesityl-copper witli 1,2-bis-idipbenylpbospbinoJediane iDPPE), for example, results in tlie fotniation of bisimesityljcopper anions and a copper cation to wbidi four pbos-pborus atoms of two DPPE molecules ate coordinated [75]. 

Finally some organocopper compounds undergo charge disproportionation under the influence of ligands that bind stron y to copper. Treatment of mesityl-copper with lj2-bis-(diphenylphosphino)ethane (DPPE) for example results in the formation of bis (mesityl) copper anions and a copper cation to whidi four phosphorus atoms of two DPPE molecules are coordinated [75]. 

Several other examples of intramolecular ruthenium-, copper-, rhodium- and iron-catalyzed cyclizations via carbometalation with polyhalocarbons are known, with a range of stereoselectivities25 4 49. Similarly, palladium-catalyzed intramolecular ene-halogenocyclization" of unsaturated a-iodo carbonyl compounds, using Pd(dppe)2, has been applied to heterocyclic synthesis26 29. 

Four closely related Cu—Se—SePh clusters are formed in the presence of either dppe, dppp, or dppb (47-50). The syntheses of isomeric, mixed valence compounds 47 and 48 containing 36 copper centers were carried out in THF the isomeric Cuag clusters 49 and 50 that formally display exclusively Cu crystallize from toluene. As well as being performed in different solvents, the reactions producing the dppp-ligated compounds 48 or 50 differed in the CuCl dppp ratios (3.1 1 for 48,5 1 for 50). The molecular structures of 47 and 49 are given as examples in Figure 3.59. 

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