ABSTRACT
The reactions of acetonitrile, propionitrile, butyronitrile, N,N-dimethylaminoacetonitrile, benzonitrile, o-tolunitrile and 1,4-dicyanobenzene with HF/AsF5 or HF/SbF5 in anhydrous HF result in protonation of the nitrile. The obtained nitrilium ions were isolated as [AsF6](-), [SbF6](-) and [Sb2F11](-) salts and characterized by multinuclear NMR and vibrational spectroscopy, and their X-ray crystal structures.
ABSTRACT
Calcium tricyanomethanide reacts with hydrogen fluoride under formation of tricyanomethane and Ca(HF2)2. Tricyanomethane is stable below -40 °C and was characterized by IR, Raman, and NMR spectroscopy. The vibrational spectra were compared to the quantum-chemical frequencies at the PBE1PBE/6-311G(3df,3dp) level of theory and confirm the predicted C(3v) symmetry of the molecule with regular C-H (109.8â pm), C-C (146.7â pm), and C≡N (114.7â pm) bonds.
ABSTRACT
We report the formation of high-precision catalysts using encapsulated rhodium complexes. In the current example, the encapsulated rhodium catalyst shows unprecedented high selectivity in the rhodium-catalyzed hydroformylation of internal alkenes, forming predominantly one of the branched aldehydes. This catalyst system is the first example that is able to discriminate between carbon atoms C3 and C4 in trans-3-octene.
