Michael addition of allenoates to electron-deficient olefins: facile synthesis of 2-alkynyl-substituted glutaric acid derivatives.

A Michael addition of allenoates to electron-deficient olefins was mediated efficiently by a catalytic amount of commercial tetra-n-butylammonium fluoride (TBAF) under mild conditions. And 2-alkynyl substituted glutaric acid derivatives, which may be potential building blocks in organic synthesis, were obtained in good to excellent yields from these reactions. The mechanism for the Michael addition reaction may involve the formation of an alkynylenolate intermediate.