Cationic molybdenum imido alkylidene complexes

Addition of 1 equiv of [HNMe2Ph]BAr4F (Ar-F = 3,5-(CF3)(2)C6H3) to Mo(NAr)(CHCMe2Ph)(Pyrrolide)(2) (Pyrrolide = parent pyrrolide (Pyr) or 2,5-dimethylpyrrolide (Me(2)Pyr)) species in THF produced [Mo(NAr)(CHCMe2Ph)(Pyrrolide)(THF)(x)]BAr4F species (x = 2 for Me(2)Pyr (1b) or 3 (1a) for Pyr; Ar = 2,6-diisopropylphenyl). [Mo(NAr)(CHCMe2Ph)(Me(2)Pyr)(2,4-lutidine)]BAr4F (1c) was formed upon addition of 2,4-lutidine to [Mo(NAr)(CHCMe2Ph)(MePyr)(THF)(2)]BAr4F (1b). Addition of 1 equiv of hexafluoro-tert-butanol to la produced (Mo(NAr)(CHCMe2Ph)[OC(CF3)(2)Me](THF)(3))BAr4F (3a), while {Mo(NAr)(CHCMe2Ph)[OCMe(CF3)(2)](THF)(2))BAr4F (3b) was obtained similarly through addition of hexafluoro-tert-butanol to 1b. Similar reactions produced unstable [Mo(NAr)(CHCMe2Ph)(O-2,6-i-Pr2C6H3)(THF)]BAr4F (3c) and [Mo(NAr)(CHCMe2Ph)(OAdamantyl)(THF)(2)]BAr4F (3d). Treatment of 1b with 2 equiv of 2,6-diisopropylphenol yielded [Mo(NAr)(CH2CMe2Ph)(O-2,6-i-Pr2C6H3)(2)]BAr4F(4). Compound 3a reacts with ethylene to yield {Mo(NAr)(CH2CH2)[OC(CF3)(2)Me](THF)(3)}BAr4F (6). The reaction between Mo(NAr)(CHCMe2Ph)(OTf)(2)(dme) and 2 equiv of Li(MesPyr) (MesPyr = 2-mesi-tylpyrrolide) gave Mo(NAr)(CHCMe2Ph)(MesPyr)(2) (2), but no cationic species could be prepared that contain 2-mesitylpyrrolide. Compounds 1a, 1c, 2, 3a, 4, and 6 were characterized crystallographically.