Pull–Pull Halogenated β‐Cyanoacrylates in Aza‐Michael Reaction: Intriguing Problem of Regioselectivity

The regioselective addition of amines to halogenated cyanoenoates as the most interesting pull–pull alkenes bearing two acceptor functions that have close electronic and steric properties is studied. The fascination with these derivatives is explained by the dramatic dependence of the reaction direction on relatively trivial changes in the halogen atom position, in the nature of solvent, presence, or absence of any additives.

Abstract

The controlled regioselective addition of nitrogen-centered nucleophiles to the pull–pull halogenated β-cyanoacrylates is a challenging problem in the chemistry of pull–pull alkenes due to the close electronic properties of the vicinal acceptor groups. The influence of the type of halogen and its position on the double bond, as well as the amine nucleophilicity and the presence of additives on the direction of addition have been studied. The experimental data are in excellent agreement with the density functional theory (DFT) calculations.

Zum Volltext