Niobium ketene hydrides

The niobium ketene-hydride complex (Cp 2Nb(H)(ii -C,0-0C CPh2)], Cp - n -CsH4SiMe3 reacts with nitriles or isonitriles to give isocyanate and the complex Cp 2NbH( C CPli2)]. Further work has been carried out on the chiral... 

Niobium ketene hydrides 11 react with t-butyl isocyanide to give t-butyl isocyanate and L2Nb(H)=C=CPh2. An intermediate 12 in this reaction is most likely formed via a [2-1-1] cycloaddition reaction . 

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