The new η3-silaallyl/alkenylsilyl molybdenumcomplex Cp*Mo(CO)2(η3-Ph2SiCHCMe2) (3) was synthesized by the reaction of Cp*Mo(CO)2(py)Me with Ph2HSiCH═CMe2. Reactions of 3 with primary amines RNH2 (R = tBu, iPr, Et) gave Mo–N–Si three-membered cyclic complexes Cp*Mo(CO)2(κ2-N,Si-RHNSiPh2) (5a, R = tBu; 5b, R = iPr; 5c, R = Et) with elimination of isobutene. In NMR tube reactions using iPrNH2 and EtNH2