抄録
The development of new efficient bond-forming reactions is important in synthetic organic chemistry. Recent developments concerning the synthetic methods utilizing highly electrophilic Michael acceptors, ethenetricarboxylates are described. Ethenetricarboxylate is a member of methylenemalonates and more reactive than alkylidenemalonates by the electron-withdrawing effect of 2-ester group. In particular, Lewis acids promote the reactions of ethenetricarboxylate derivatives efficiently. Various nucleophiles could undergo conjugate additions and the further bond-forming reactions. The high functionalization of the products may be useful for further elaboration.
This paper describes catalytic Friedel-Crafts/Michael addition reactions of indoles, conjugate addition of amines, and various cycloadditions with compounds such as propargyl amines/alcohols, aminobenzaldehydes, and allenes in the presence of Lewis acid to give nitrogen and oxygen-containing heterocyclic and carbocyclic compounds. One-pot reactions with compounds such as aminoalcohol and Huisgen zwitterion in the absence of Lewis acids lead to various heterocyclic compounds. Lewis acid-promoted intramolecular cyclization reactions of functionalized ethenetricarboxylate derivatives has also been described.
