Metallation and functionalization of 1‐allenylpyrrole

Abstract 1‐Allenylpyrrole is lithiated at the α‐carbon atom of the allenyl group by n‐butyllithium in mixtures of diethyl‐ether/hexane or tetrahydrofuran/hexane. Whereas functionalization with trimethylchlorosilane, butyl iodide and dimethyl disulfide gives only allenic derivatives, addition of carbonyl compounds generally leads to mixtures of allenic and acetylenic derivatives. Upon heating its solutions in ether or tetrahydrofuran, Li‐allenylpyrrole is slowly transformed into the lithium derivative of 1‐(propyn‐2‐yl)pyrrole.