Orthomanganation of arylhydrazones and related N-donor substrates
摘要:
The N-phenyl- and N,N-diphenylhydrazones of benzaldehyde or acetophenone are readily cyclometallated on reaction with PhCH2Mn(CO)(5) to give complexes 3 of the type (OC)(4)MnC6H4C(R-1)=NNPhR2 incorporating a five-membered MnC3N ring. The example with R-1 = Me, R-2 = H has been structurally characterised. The similar reaction with the N,N-diphenylhydrazone of cyclohexanone produces a species with an alternative MnC2N2 ring which was also structurally characterised. A related species (OC)(4)MnC6H4NN=O is formed from N-nitrosodiphenylamine. Reactions of compounds 3 from the diphenylhydrazones with alkynes PhC=CPh or Me3SiC=CH give N'-indenyl-N,N-diphenylhydrazines in reasonable yields. (C) 1998 Elsevier Science S.A. All rights reserved.