Reactivity of Bis(3,5-dimethylpyrazol-1-yl)methyllithium with S or CS2, Followed by Reaction with Fe3(CO)12 and Ar3SnCl or RX: Unexpected Formation of (3,5-Dimethylpyrazol-1-yl)dithioformate Derivatives

Reaction of bis­(3,5-dimethylpyrazol-1-yl)­methyllithium with sulfur at −70 °C, followed by reaction with Fe3(CO)12 and triaryltin chlorides, yielded trinuclear butterfly cluster complexes. When the triaryltin chlorides were replaced by organic halides, unexpected (3,5-dimethylpyrazol-1-yl)­dithioformate derivatives were obtained. In addition, treatment of bis­(3,5-dimethylpyrazol-1-yl)­methane with n-BuLi at 0 °C resulted in partial decomposition to yield a carbene intermediate and a 3,5-dimethylpyrazolate anion. The carbene intermediate readily dimerized, and reaction of the anion with carbon disulfide, and subsequently with Fe3(CO)12 and organic halides, also gave the dithioformate derivatives.