Lanthanide and asymmetric catalyzed syntheses of sterically hindered 4-isoxazolyl-1,4-dihydropyridines and 4-isoxazolyl-quinolones

[Display omitted] The Ytterbium (III) triflate catalyzed Hantzsch synthesis allows for the preparation of sterically hindered 4-isoxazolyl-1,4-dihydropyridines in moderate to good yields. Asymmetric organocatalysis with (R)-4-Oxo-2,6-bis-(2,4,6-triisopropyl-phenyl)-3,5-dioxa-4l5-phospha-cyclohepta[2,1-a;3,4-a’]dinaphthalen-4-ol (R-TRIP) produces moderate yields of chiral 4-isoxazolyl-quinolones with high enantioselectivity.