Enantioselective Intramolecular C-H Insertion Reactions of α-Diazo β-Keto Esters Catalyzed by Dirhodium(II) Tetrakis[N-phthaloyl-(S)-phenylalaninate]: The Effect of the Substituent at the Insertion Site on Enantioselectivity

All articles of this category The enantioselectivity in dirhodium(II) tetrakis[ N -phthaloyl-( S ) -phenylalaninate]-catalyzed cyclization of α-diazo β-keto 2,4-dimethyl-3-phenyl esters possessing substituted phenyl or vinyl groups at the insertion site was studied. The substituent effects on enhancement of the enantioselectivity were even more pronounced with the vinyl group than with the phenyl group, though 80% ee could be achieved with both of the ( E )-conjugated ester and p -trifluoromethanesulfonyloxyphenyl groups.