DECOMPLEXATION OF (ETA-ARENE)(ETA-CYCLOPENTADIENYL)IRON(II) HEXAFLUOROPHOSPHATES - A CONVENIENT ONE-POT ARYLATION PROCEDURE

gA study has been made of the relative merits of a range of decomplexa tion reagents in the demetallation of [(eta-arene)(eta-cyclopentadieny l)Fe][PF6] salts. 1,8-Phenanthroline gave good yields of the free liga nd when simple arene complexes were used but did not demetallate more sterically hindered species. The reaction was found to be tight sensit ive. Bipyridine gave much lower yields. Potassium tert-butoxide in pyr idine or DMSO was found to be an excellent demetallating agent even wi th sterically crowded complexes. A one-pot arylation procedure was dev eloped and extended to include a number of important heterocyclic deri vatives. The mechanism of these decomplexation reactions is briefly ad dressed.