Decarboxylative Michael Additions of Substituted Malonic Acid Half‐Oxyesters to Methylidene Malonates

Decarboxylative Michael additions between substituted malonic acids half oxyesters (SMAHOs) and methylidene malonates have been achieved using either a catalytic amount of a weak base such as N‐methyl‐morpholine (NMM) or di‐iso‐propylamine (DIPEA) in a refluxing solvent. This transformation occurs under practical conditions (bulk solvent and open to air) and can be performed with various SMAHOs and methylidene malonates, in yields ranging from 22 to 89%. NMR studies support the occurrence of a Michael addition pre‐decarboxylation mechanism.