Abstract
New L-serine derivative ligands were prepared and tested as cocatalyst in the Diels-Alder reactions between cyclopentadiene (CPD) and methyl acrylate, in the presence of several Lewis acids. The catalytic potential of the in situ formed complexes was evaluated based on the reaction yield. Bidentate serine ligands showed good ability to coordinate medium strength Lewis acids, thus boosting their catalytic activity. The synthesis of the L-serine ligands proved to be highly efficient and straightforward.
Highlights
The synthesis of bicyclic compounds has large significance due to their use as synthetic intermediates in the preparation of a vast variety of compounds of chemical, biological, and pharmaceutical interest [1, 2]
We studied the use of moderate strength Lewis acids as catalysts for Diels-Alder reaction between CPD (1) and methyl acrylate (2) in dichloromethane (Scheme 1), by complexing insoluble metal ions with novel L-serine derivative ligands, as alternative to the usual strong Lewis acids
The work started with the study of several Lewis acids tested as catalysts in the Diels-Alder reaction between CPD (1) and methyl acrylate (2) using dichloromethane as solvent; the results are summarized in Table 1, as well as the reaction conditions
Summary
The synthesis of bicyclic compounds has large significance due to their use as synthetic intermediates in the preparation of a vast variety of compounds of chemical, biological, and pharmaceutical interest [1, 2]. The acid catalyzed Diels-Alder reactions, namely, between cyclopentadiene (CPD) and acrylates, is well documented [1, 3,4,5,6,7,8,9,10,11,12,13,14,15], the most important used Lewis acids being Al(III), Fe(III) or boron complexes. The use of such strong acids is needed because ester dienophiles (as acrylate ones) are not very reactive [15, 16]. The solvent used is a factor to consider regarding both the Lewis acid solubility and the reaction media’s polarity, dichloromethane being the most used solvent as combines both properties
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
