Aza-Michael Additions of Benzylamine to Acrylates Promoted by Microwaves and Conventional Heating Using DBU as Catalyst via Solvent-Free Protocol

In recent years, the use of solvent-free reactions represents a challenge for organic chemists, since it would help to optimize methodologies and contribute to the development of sustainable chemistry. In this regard, our research group has intensified efforts in the search for reactions that can be carried out in the absence of a solvent. In this paper, we present a protocol for the aza-Michael addition of benzylamine to alpha,beta-unsaturated esters to prepare N-benzylated beta-amino esters in the presence of catalytic amounts of DBU (0.2 eq) via solvent-free reaction. Depending on the alpha,beta-unsaturated esters, we observed a reduction in reaction times, with good to excellent yields for aza-Michael addition.