Ni-catalyzed synthesis of acrylic acid derivatives from CO₂ and ethylene

The story of nickelalactones finally ends well. Over three decades after their discovery, catalytic processes have been successfully established to synthesize acrylate derivatives from ethylene and abundantly available carbon dioxide. The performed research during this time in the CO₂ utilization via C-C bond formation with olefins is presented within this review. It gives detailed insights starting from the initial milestones in the 1980s up to modern strategies through cleavage auxiliaries. Different approaches are examined from an experimental and theoretical point of view as the choice of cleavage agent and the corresponding ligand is crucial for the reaction control and suppression of undesired pathways. Methylation of the lactone species led to a first successful liberation of methyl acrylate in stoichiometric amounts. These results led to a vast progress in research with auxiliaries afterward. Upon addition of Lewis acids or strong sodium bases, finally the first two different catalytic routes have been established which are discussed in detail.