Chiral (thio)phosphorodiamides as excellent hydrogen bond donor catalysts in the asymmetric Michael addition of 2-hydroxy-1,4-naphthoquione to nitroolefins
A novel type of bidentate hydrogenbonddonor catalysts based on (thio)phosphorodiamides catalophore has been developed for the asymmetric Michael addition of 2-hydroxy-1,4-naphthoquione to nitroolefins, affording the corresponding adducts in high yields with excellent level of enantioselectivities (97- >99% ee).
BINOL–quinine–squaramides as efficient organocatalysts for the asymmetric Michael addition of 2-hydroxy-1,4-naphthoquinone to nitroalkenes
作者:Enshan Zhou、Bin Liu、Chune Dong
DOI:10.1016/j.tetasy.2013.11.019
日期:2014.1
A set of BINOL-quinine-squaramides were synthesized, and then used as organocatalysts to promote the catalytic enantioselective Michael addition reaction of 2-hydroxy-1,4-naphthoquinone to nitroalkenes with excellent yields and ees (up to 99% yield and 93% ee) at low catalyst loading (0.5 mol %). (C) 2013 Elsevier Ltd. All rights reserved.