Synthesis of N,N-Dimethylaminoethyl Acrylate via a Zinc Phenoxyimine and Phenoxyamidine Complexes Catalyzed Transesterification Reaction

Abstract

Heteroleptic and homoleptic complexes of zinc with phenoxyimine and phenoxyamidine ligands are used as alternatives to currently used tin catalysts in the transesterification reaction of methyl acrylate and N,N-dimethylethanolamine in the synthesis of N,N-dimethylaminoethyl acrylate. A large screening of phenoxyimine and three generations of phenoxyamidine ligands has been undertaken and used to determine the best catalysts in terms of conversion and selectivity. All of the catalysts tested show significant improvement in activity over catalysts currently well-established in industrial processes such as dibutyltin oxide or Ti(OⁱPr)₄. The catalytic charges can be decreased significantly (10–20×) still affording good conversions and selectivities. A series of heteroleptic and homoleptic zinc complexes with phenoxyimine and phenoxyamidine ligands have been tested for the transesterification of methyl acrylate with N,N-dimethylethanolamine. All the catalysts demonstrated a substantial increase in activity compared to dibutyltin oxide, a well-established catalyst that is currently used in industry for this reaction.