Results Precursors of Dimethylcarbene Complexes. There are three general routes to electrophilic carbene complexes which are not stabilized by an a-heteroatom:(1) the addition of electrophiles to MCRR'X systems, 2-10v12 (2) protonation or alkylation of vinyl metal c~ mplexes~-~~ J~ and (3) a-hydrogen abstraction from metal-alkyl system~.~ J~ For the synthesis of dimethylcarbene complex 1, we investigated the synthesis and reactivity ...