Organocatalytic Asymmetric Direct Aldol Reactions of Trifluoroacetaldehyde Ethyl Hemiacetal with Aromatic Methyl Ketones
作者:Kazumasa Funabiki、Yuya Itoh、Yasuhiro Kubota、Masaki Matsui
DOI:10.1021/jo200020z
日期:2011.5.6
The organocatalytic asymmetric direct aldol reaction of trifluoroacetaldehyde ethyl hemiacetal with aromatic methyl ketones in the presence of a catalytic amount of (S)-5-(pyrrolidin-2-yl)-1H-tetrazole in dichloroethane at 40 °C proceeds smoothly to produce (R)-4,4,4-trifluoro-1-aryl-3-hydroxy-1-butanones in high yields with up to 90% ee.
三氟乙醛乙基半缩醛与芳族甲基酮在催化量的(S)-5-(吡咯烷-2-基)-1 H-四唑在二氯乙烷中的存在下于40°C进行有机催化的不对称直接醛醇缩合反应顺利进行,得到了(R)-4,4,4-三氟-1-芳基-3-羟基-1-丁酮,高收率,ee高达90%。