Primary Amine-Thioureas with Improved Catalytic Properties for “Difficult” Michael Reactions: Efficient Organocatalytic Syntheses of (S)-Baclofen, (R)-Baclofen and (S)-Phenibut
作者:Michail Tsakos、Christoforos G. Kokotos、George Kokotos
DOI:10.1002/adsc.201100636
日期:2012.3
Among the class of primary amine‐thioureas based on tert‐butyl esters of α‐amino acids, the most efficient organocatalyst for “difficult” Michael reactions was identified. The derivative based on (S)‐di‐tert‐butyl aspartate and (1R,2R)‐diphenylethylenediamine provided the products of the reaction between aryl methyl ketones and nitroolefins in excellent yields and enantioselectivities. In addition
在基于α-氨基酸叔丁基酯的伯胺硫脲类中,发现了“难”迈克尔反应最有效的有机催化剂。基于(S)-二叔丁基天冬氨酸盐和(1 R,2 R)-二苯基乙二胺的衍生物提供了芳基甲基酮与硝基烯烃之间反应的产物,收率和对映选择性极好。另外,这种新催化剂可以以低催化剂负载量(5mol%)使用。有效合成(S)-baclofen,(R)-baclofen和(S)-phenibut的方法突显了这种方法的实用性。