Aminolysis of cyclic carbamate analogs of carboxybiotin; metallic catalysis and modelling of carboxytransferase

Article abstract of DOI:10.1016/S0040-4020(01)90121-8

Aminolysis of carbamic esters, a model of the intermediate carboxybiotin in enzymatic carboxylations was studied in organic medium in the presence of a divalent cation. This study establishes electrostatic catalysis of aminolysis, the rate determining step of which is the collapse of the tetrahedral intermediate principally by carbon-nitrogen bond breaking. The results also account for the role of the divalent cation present in the carboxytransferase subunit of carboxylases.