Search

The enantioselective synthesis of endothelin-A antagonist ABT-546 is carried out through the discovery and development of a highly selective catalytic asymmetric conjugate addition of ketosters to nitroolefins. The effects of ligand structure, metal salt, and solvent on the reaction are described.

The development of a catalyst system for the conjugate addition of 1,3-dicarbonyl compounds to nitroalkenes is described. The reactions proceed with excellent facial selectives at eh conjugate acceptor and with low catalyst loading.

Researchers assessed ligand literature, medium effects and metal sources to design an effective enantioselective copper catalyzed aziridination reaction while analyzing the role of bis(oxazoline)-copper complexes as chiral catalysts for the enantioselective aziridination of olefins. They discovered that the optimal conditions observed for the aziridination of cinnamate esters, which are the most synthetically advantageous substrate type, cannot be dependably extended to other olfenic substrates.

The scope of the Diels-Alder reaction catalyzed by bis(oxazoline) copper complexes was studied. Specifically, (Cu((S,S)-t-Bu-box))(SbF6)2 was found to catalyze the Diels-Alder reaction between 3-propenoyl-2-oxazolidinone and a range of substituted dienes with high enantioselectivity. This cationic complex was also used in the catalysis of analogous intramolecular processes with good success. The total syntheses of ent-Delta1-tetrahydrocannabinol, ent-shikimic acid, and isopulo'upone, featuring the use of this chiral catalyst in more complex Diels-Alder processes, are presented.