Synthesis and reactivity of mixed-ring indenyl complexes of molybdenocene

The complex [IndCpMo(NCMe)2][BF4]2 provides a suitable entry to the synthesis of IndCpMoBr2 and IndCpMoMe2. The latter, also available from IndCpMoX2 (X = Cl, Br) and MeMgCl, reacts with HCl to give IndCpMoCl(Me) which, in turn reacts with NaSPh to yield IndCpMo(SPh)(Me). Cyclic voltammetry shows that these three alkyl complexes undergo a 1e reversible oxidation to 17 e MoV cations. IndCpMoCl(Me) is oxidized by [Cp2Fe]BF4 to afford [IndCpMoCl(Me)]BF4 in 95% yield. Reaction of [IndCpMo(NCMe)2][BF4]2 with KBPz4 in CH2Cl2/NMF leads to [IndCpMo(κ2-BPz4)]BF4. Taken together with previous reports these results show that the indenyl ring slows down substitutional chemistry at the View the MathML sourceCp2′Mo(IV) fragment (Cp′ = Cp, Ind) by steric reasons, overshadowing any acceleration due to a possible indenyl effect.