ChemInform Abstract: Reaction of Alkenynamines with Esters of Aliphatic and Aromatic Carboxylic Acids.
Abstract
The ynamines (I) undergo regiospecific (2 + 2)-cycloaddition at the acetylenic bond to the ester carbonyl bond of ethyl acetate (IIa) or methyl benzoate (IIb) to give oxete intermediates, whose spontaneous cleavage yields the products (III).
ChemInform Abstract
The ynamines (I) undergo regiospecific (2 + 2)-cycloaddition at the acetylenic bond to the ester carbonyl bond of ethyl acetate (IIa) or methyl benzoate (IIb) to give oxete intermediates, whose spontaneous cleavage yields the products (III). The reactions proceed only in the presence of stoichiometric amounts of MgBr2·Et2O or BF3·Et2O. The reactions between the ynamines (I) and the amino esters (IV) proceed regiospecifically at the amino group of the amino esters to give the amidines (V). The ester carbonyl group is not affected by these reactions.
