Nitro and nitrato complexes of cyclopentadienyl(N,N-dialkyldithiocarbamato)cobalt( III). Preparation and use as oxidants

Article abstract of DOI:10.1021/om50005a029

The preparation of a series of cyclopentadienyl(N,N-dialkyldithiocarbamato)cobalt(III) complexes, CpCo(S₂CNR₂)X (R = CH₃, C₂H₅; X = I, NO₂, NO₃) and CpCo(S₂CN(CH₃)₂)L]X (L = Ph₃P, X = I, BF₄; L = CH₃CN, X = BF₄), is described. Mixtures of CpCo(S₂CN(CH₃)₂)NO₂ and BF₄·Et₂O were found to oxidize benzyl alcohol to benzaldehyde. The reaction is stoichiometric in the absence of oxygen. Benzyl alcohol is also oxidized by mixtures of CpCo(S₂CN(CH₃)₂)NO₃, PPNNO₂, and PPNNO₃ (PPN = (Ph₃P)₂N) with BF₃·Et₂O. The oxidations by the nitrate species are catalytic in the presence of oxygen. The detailed results rule out mechanisms for the metal nitro complex reactions that involve metal-bound nitrogen oxide ester intermediates. A mechanism in which NO₂^- reacts with BF₃ to give the actual oxidant is proposed.