Synthesis of Tertiary Fatty Amines in Water: The Dual Role of Dimethylamine as Reagent and Phase Mediator in the Homogeneously Catalyzed Fatty Alcohol Amination

The amination of long-chain fattyalcohols with dimethylamine tothe desired tertiary amines proceeds in water as the solvent withunprecedented conversions and selectivities exceeding 99%. Key tosuccess was the combination of a water-soluble ruthenium-based catalystand the unique phase-mediating properties of the cosubstrate dimethylamine.After the reaction, the homogeneous mixture split into a pure productphase and catalyst-containing aqueous phase upon reducing the pressure,enabling the straightforward isolation of high-purity products. Severalfatty alcohols were successfully transformed into the respective tertiaryfatty dimethyl alkyl amines under these unique conditions. The unique dual role of dimethylamineas a phase mediatorand substrate for the effective and selective conversion of long-chainfatty alcohols to water is described.