Lanthanide and asymmetric catalyzed syntheses of sterically hindered 4-isoxazolyl-1,4-dihydropyridines and 4-isoxazolyl-quinolones
作者:Scott A. Steiger、Chun Li、Charles F. Campana、Nicholas R. Natale
DOI:10.1016/j.tetlet.2015.12.038
日期:2016.1
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-415-phospha-cyclohepta[2,1-a;3,4-a']dinaphthalen-4-ol (R-TRIP) produces moderate yields of chiral 4-isoxazolyl-quinolones with high enantioselectivity. (C) 2015 Elsevier Ltd. All rights reserved.