| Popis: |
The creation of asymmetric ligands with lower environmental impact is important, as such chiral N,N' ligands attract some attention. A new method for the synthesis of 1,2,4-trisubstituted amino azetidines with \(cis\) relative configuration across its two stereogenic centres was reported in 2013. Due to this \(cis\) conformation, the azetidine compounds are expected to be good chiral ligands for asymmetric catalysis. The nitro aldol (Henry) reaction is an established method for producing new carbon-carbon bonds and is a key reaction in the synthesis of many important compounds. Enantioselective Henry reactions generate carbon-carbon bonds and our azetidines are probed as ligands for that reaction. In this work, new azetidines and their palladium and platinum complexes were prepared and characterised by techniques including X-ray diffraction, confirming retention of the \(cis\) conformation. Furthermore, enantiopure \(cis\)-azetidines were used as chiral ligands for a range of transition metals including the use of Cu-azetidine complexes as catalysts for the Henry reaction, in up to >99.5% ee. New enantiopure amino azetidines and their transition metal complexes are demonstrated as asymmetric catalysts for the asymmetric Henry reaction. |
