Synthesis and reactivity of 1-chloro-2-methylthio-ferrocene and 1,1′-dichloro-2,2′-bis(methylthio)ferrocene. Molecular structure of 1-chloro-2,5-bis(methylthio)ferrocene

Lithiation of chloroferrocene (1a) with n-butyl lithium or lithium tetramethylpiperidinide (LiTMP) followed by addition of dimethyldisulfide gives 1-chloro-2-methylthioferrocene (2). Renewed treatment of 2 with LiTMP and MeSSMe yields 1-chloro-2,5-bis(methylthio)ferrocene (3), the structure of which was determined by X-ray diffraction. The reaction of 1,1′-dichloroferrocene (1b) with n-butyl lithium in the presence of TMEDA followed by addition of MeSSMe gives 1,1′-dichloro-2,2′-bis(methylthio)ferrocene as a diastereomeric 1:2 mixture of the meso and d,l form.