Abstract Lithium atoms were cocondensed with eight aromatic five-membered heterocycles in the presence of THF at 77 K. In the case of the oxygen-and sulfur-containing heterocycles (furans and thiophenes), the reaction resulted in C− H bond activation and led to the corresponding aryllithium compound. The other heterocycles (pyrroles) failed to react with lithium atoms in the presence of THF. A special case was found when oxazole was ...
