Methylidyne tricobalt nonacarbonyl clusters; optically active silicon and germanium derivatives,and substitutions at silicon

The preparation and alcoholysis of chiral chlorosilanes containing the nonacarbonyltricobaltcarbon cluster, RR′Si(Cl)CCo₃(CO)₉, is described. The alkoxy derivatives react with i-Bu₂AlH or BF₃ · Et₂O to give the corresponding silicon hydride or fluoride. Reaction of methylidynetricobalt nonacarbonyl with optically active silanes of germane gave the optically active cluster complexes R¹R²R³M^*CCo₃(CO)₉ (M^* = Si, Ge). These compounds react with phosphine to give the monosubstituted R¹R²R³M^*CCo₃(CO)₈(PR₃ (M^* = Si, Ge). The diastereomers have been resolved in the case of the MePhSi (Obornyl) CCo₃(CO)₉ complex.