Old and the New: Studies of Metal-Catalysed Exchange by (3)H NMR Spectroscopy.

摘要

Studies of the use of platinum, palladium and Raney nickel catalysts for exchange into organic substrates under mild conditions have been undertaken. Encouraging results were obtained with Raney nickel as catalyst, with high activity and specificity of label, with a number of pilot experiments yielding tritiated hydrocarbons with specific activities in the region of 30-400 GBq/mmole. NMR analyses of products and have shown that the mechanism of the exchange process is accessible, that aromatic vs aliphatic effects may be quantified, and that the resolution of modern day NMR instruments allows simple resolution of multiply labeled species. With extension of these experiments to more diverse substrates, and with careful radio-GLC and (3)H NMR analyses, we have gained insight into the range of application and the exchange mechanisms of these procedures. 13 refs., 2 figs., 1 tab.