UC Riverside

Reactions between Mo(NAr)(CHR)(Me₂Pyr)-(OTPP) (Ar = 2,6-i-Pr₂C₆H₃, R = H or CHCMe₂Ph, Me₂Pyr = 2,5-dimethylpyrrolide, OTPP = O-2,3,5,6-Ph₄C₆H) and CH₂=CHX where X = B(pin), SiMe₃, N-carbazolyl, N-pyrrolidinonyl, PPh₂, OPr, or SPh lead to Mo(NAr)(CHX)-(Me₂Pyr)(OTPP) complexes in good yield. All have been characterized through X-ray studies (as an acetonitrile adduct in the case of X = PPh₂). The efficiencies of metathesis reactions initiated by Mo(NAr)(CHX)(Me₂Pyr)(OTPP) complexes can be rationalized on the basis of steric factors; electronic differences imposed as a consequence of X being bound to the alkylidene carbon do not seem to play a major role. Side reactions that promote catalyst decomposition do not appear to be a serious limitation for Mo=CHX species.