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