FORMATION AND SYNTHETIC UTILITY OF FORMYLCYCLOPENTADIENYLTHALLIUM, ACETYLCYCLOPENTADIENYLTHALLIUM, CARBOMETHOXYCYCLOPENTADIENYLTHALLIUM, AND CARBOETHOXYCYCLOPENTADIENYLTHALLIUM

Formyl- (1), acetyl- (2), carbomethoxy- (3) and carboethoxycyclopentadienylthallium (4) have been prepared in high yields from reactions of the corresponding functionally substituted cyclopentadienylsodium salts with thallium ethoxide in ethanol solution. Products 1-4 so produced are readily isolated as air-stable solids, and have been characterized by their 1H and 13C NMR spectra. Reactions of 1-4 with Mn(CO)5Br, Re(CO)5Br or [Rh(CO)2Cl]2 provide convenient routes to the respective functionally substituted cyclopentadienyl derivatives of manganese, rhenium or rhodium, and demonstrate the utility of 1-4 in organometallic syntheses. © 1990.