Chiral Squaramide-Catalyzed Highly Enantioselective Michael Addition of 2-Hydroxy-1,4-naphthoquinones to Nitroalkenes
作者:Wen Yang、Da-Ming Du
DOI:10.1002/adsc.201000981
日期:2011.5
A chiral squaramide‐organocatalyzed, highlyenantioselectiveMichaeladdition of 2‐hydroxy‐1,4‐naphthoquinones to nitroalkenes has been developed. This reaction afforded the chiral naphthoquinones in excellent yields (up to 99%) and excellent enantioselectivity (up to 98% ee) under very low catalyst loading (0.25 mol%). This organocatalytic asymmetric Michaeladdition provides an efficient alternative
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.