Metalation of polystyrene and its model compound 1,3,6,8‐tetraphenyloctane by the sec‐butyllithium‐N,N,N′,N′‐tetramethylethylenediamine complex

Abstract 1,3,6,8‐Tetraphenyloctane (1) the tetramer of styrene was metalated by a complex of sec‐butyllithium with N,N,N′,N′‐tetramethylethylenediamine in cyclohexane. The lithiated styrene tetramer was quenched with deuterium oxide, and the deuterated compounds were examined by mass, 1H NMR and IR spectrometry. The spectroscopic data revealed that the lithium atoms are placed chiefly at the aromatic ring. The meta/para distribution of metalated sites in the aromatic ring was found to be approximately 2:1. Polystyrene was lithiated with the same complex. The amount of lithium in the polymer could be varied over a wide range. It was found that each lithium atom in the polymer can be substituted by a functional group, thus permitting the introduction of a controlled number of functional groups. By use of this metalation technique, phosphonate groups could be introduced into the aromatic rings of polystyrene.