Reactions of the rhenium allyl hydrido complex Cp*Re( η3-C 3H 5)(CO)(H) with the electrophiles CF 3CO 2H, CF 3SO 3H, NOBF 4, [ p-N 2C 6H 4OMe][BF 4] and [Ph 3C][BF 4

Abstract

The rhenium hydrido allyl complex Cp*Re( η 3-C 3H 5)(CO)(H) ( 1) reacted with NOBF 4 or [ p-N 2C 6H 4OMe][BF 4] at −78°C to give [Cp*Re( η 2-C 3H 6)(CO)(NO)][BF 4] ( 2) or [Cp*Re( η 2-C 3H 6)(CO)(N 2C 6H 4OMe)][BF 4] ( 3), respectively. In these reactions addition of the electrophile is accompanied by transfer of the hydride ligand to the allyl group to form the propene ligand. Complex 1 reacted with [Ph 3C][BF 4] in CH 3CN at −78°C to abstract the hydride ligand and form the allyl acetonitrile complex [Cp*Re( η 3-C 3H 5)(CO)(CH 3CN)][BF 4] ( 4). Complex 1 reacted with CF 3CO 2H or CF 3SO 3H to form the hydrido propene complexes Cp*Re( η 2-C 3H 6)(H)(CO)(CF 3CO 2) (5) or Cp*Re( η 2-C 3H 6)(H)(CO)(CF 3SO 3) ( 6). Studies with CF 3CO 2D demonstrated that both Cp*Re( η 2-C 3H 6)(D)(CO)(CF 3CO 2) and Cp*Re( η 2-C 3H 5D)(H)(CO)(CF 3CO 2) are formed. This is consistent with a mechanism in which D + attacks the metal followed by transfer of either D or H to the allyl group. Complex 1 was found not to react with C 2H 4, hexene, cyclohexene, MeCCMe, PhCCMe, CH 3CN or PMe 3.