C-HYDROXYALKYLATION OF N-ARYLANILINES WITH POLYFLUOROCARBONYL COMPOUNDS - THEORETICAL-STUDY

Quantum chemical AM1 calculations with full geometry optimization are carried out for N-methylaniline (2), tetrahydroquinoline (3), indoline (4) molecules, as well as for the products and reaction intermediates of their C-hydroxyalkylation with hexafluoroacetone (1). Enthalpies o f formation, frontier orbital energies, and atomic charge distribution s are determined for all systems examined. These values are used to es timate the relative stabilities of adducts formed by donor-acceptor in teraction between amino- and carbonyl groups using the Klopman perturb ation theory. The complexes of 1 with 2 and 1 with 4 are concluded to have the longest and shortest lifetimes, respectively. The results of the theoretical study allow one to explain the experimentally observed increase in the propensity for ortho-C-hydroxyalkylation in the serie s 2 < 3 < 4. The reduction of the ability of methyl trifluoropyruvate to undergo ortho-C-hydroxyalkylation is shown to be a consequence of t he greater stabilities of its arylamine complexes.