Salt effects on the Baylis–Hillman reaction

The Baylis–Hillman reaction is shown to accelerate in salt solutions of water and the ‘water-like’ structured solvents, like formamide and N-methylformamide in the presence of DABCO. Ethylene glycol, another structured solvent and its salt solutions fail to make any impact on the reaction rates. The salts that are conventionally defined as salting-out or -in do not behave in a similar fashion, when employed in the Baylis–Hillman reactions. The results are supported by solubility measurements. It seems that the cation, anion, nature of solvent and of reactants together ascertain whether a salt will enhance or retard the Baylis–Hillman reaction.