Anisole tricarbonylchromium

Solutions of this compound and other arenetricarbonylchromiums can only be handled for very brief periods in air. The workup procedures are therefore best carried out in an inert atmosphere throughout, but they can be conducted in air if done rapidly and efficiently. 

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Activation of aromatic compounds by transition-metal complexes was initially studied with Cr(CO)3 complexes. Nucleophilic addition of 2-lithio-l,3-dithianes to arene-chromium(O) complexes 185 followed usually by iodine-promoted decomplexation affords the corresponding 2-arylated 1,3-dithianes 186. The reaction of //-(toluene)- and (anisole)tricarbonylchromium (185) with compound 161 gave mixtures (52 46 and 10 90, respectively) of ortho and meta substituted derivatives (186) (Scheme 54)244. The meta directing effect was also observed (mainly better than 95%) with amino and fluoro substituted complexes245. 

In-situ decomposition of (rf-benzene)tricarbonylchromium(O) and (if-anisole)tricarbonylchromium(O) complexes on Na-XzeoHte was studied via temperature-programmed reaction and DRIFT by Shirley and Scoville [927]. At increasing temperatures, the decomposition could be monitored, for instance, by the change from the band of complexed benzene (1452 cm ) to that of adsorbed benzene (1477 cm ). Similarly, the change from the spectriun of intact (q -ben-zene)tricarbonylchromium(O) complex to that of a surface Cr(CO)3 complex with CO absorbances at 1917 and 1773 cm was observed. 

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