877763-25-2Relevant academic research and scientific papers
Rhodium-catalyzed deallylation of allylmalonates and related compounds
Tursky, Matyas,Necas, David,Drabina, Pavel,Sedlak, Milos,Kotora, Martin
, p. 901 - 907 (2006)
Various allylmalonates and other related compounds were selectively deallylated in the presence of a catalytic amount of a rhodium complex and an excess of triethylaluminum. Comparison of several phosphane (PPh3) and BIAP (bis(imidazolonyl)pyridine) rhodium complexes showed that the latter are more active and general with respect to the structural diversity of the substrate then the former. It was shown that the role of triethylaluminum is not only to generate in situ a rhodium hydride, which is assumed to be the catalytically active species, but also to act as a Lewis acid to activate the carbonyl group of the substrate. Thus, the proposed mechanism of deallylation involves hydrorhodation of the double bond along with activation of the carbonyl group of the substrate by triethylaluminum followed by a sequence of bond formations and cleavages, furnishing an enolate and an alkene. The methodology provides an efficient and selective route to deallylation of allylmalonates under mild reaction conditions.
