99707-13-8Relevant articles and documents
Reactions of alkyl and hydride derivatives of permethylscandocene and -zirconocene with nitriles and amines. Catalytic hydrogenation of tert-butyl cyanide with permethylscandocene hydride
Bercaw, John E.,Davies, David L.,Wolczanski, Peter T.
, p. 443 - 450 (2008/10/08)
The compounds Cp*2ScR (Cp* = η5-C5Me5; R = H, Me, p-tol) react readily with nitriles R′CN to provide azomethine complexes Cp*2ScNC(R)R′ containing a C=N double bond (v(CN) 1640-1680 cm-1). If Cp*2ScMe is used, further reaction may occur to give products containing two nitriles. The related complex Cp*2ZrH2 will insert two nitriles in a stepwise manner; however, the dimethyl analogue is unreactive toward nitriles. The compounds Cp*2ScNC(H)R may be hydrogenated under relatively mild conditions to yield the corresponding amide complexes Cp*2ScNHCH2R. This transformation is reversible; addition of ethylene leads to dehydrogenation of the amide complex and production of ethane. The amide complexes may be independently synthesized by reaction of Cp*2ScR (R = H, Me) and the corresponding amine, with resultant elimination of hydrogen or methane, respectively. Cp*2ScNHCH2CMe3 will catalytically hydrogenate (4 atm of H2) Me3CCN to Me3CCH2NH2; however, termination occurs by insertion of the nitrile into the scandium-amide bond to form Cp*2ScNC (CMe3)NHCH2CMe3, the NC bond of which is not hydrogenated under these conditions. Labeling experiments show that hydrogen can add reversibly across the Sc-N bond of the amide, and this step is believed to play a crucial role in the catalytic reaction.
