Journal of the American Chemical Society p. 5635 - 5643 (1980)
Update date:2022-08-23
Topics:
Leussing, Daniel L.
Raghavan, N. V.
Monoprotonated ethylenediamine (ENH+) and aminoacetonitrile (AAN) are highly effective catalysts for the decarboxylation of oxalacetate (OA2-) with the latter amine showing 50percent faster rates.The mechanisms of the reactions are the same as that earlier proposed by Guthrie and Jordan from studies on the carboxylation of acetoacetate (AA-): amine and keto acid react to form ketimine which either decarboxylates or is competitively converted to enamine.We find that a prton is required to effect decarboxylation, but it also promotes enamine formation, the more so the greater basicity of the parent amine.Owing to this side reaction, the more basic amines tend to show lower catalytic activity with respect to decarboxylation. a second effect also contributes to the high activity of AAN: even though the rate constants for imine formation appear to be roughly similar with AAN and ENH+, proton catalysis has a much larger net influence on the AAN rate because changes in
Doi:10.1080/15257770600894410
(2006)Doi:10.1039/C19660000830
(1966)Doi:10.1021/om400625q
(2013)Doi:10.1016/S0040-4020(98)00782-0
(1998)Doi:10.1021/ja01466a050
(1961)Doi:10.1016/j.molliq.2021.116969
(2021)