Asymmetric Conjugate Addition of Acetylacetone to Nitroolefins with Chiral Organocatalysts Derived from Both α-Amino Acids and Carbohydrates
作者:Xuewei Pu、Penghui Li、Fangzhi Peng、Xiaojiao Li、Hongbin Zhang、Zhihui Shao
DOI:10.1002/ejoc.200900547
日期:2009.9
chiral tertiary amine thioureas derived from both α-amino acids and carbohydrates were developed. These organocatalysts promoted the enantioselective conjugate addition of acetylacetone to various aromatic and aliphatic nitroolefins at room temperature in good yields (up to 93 %) and with good enantioselectivity (up to 90 % ee). Furthermore, an interesting matched–mismatched effect of two different
开发了衍生自 α-氨基酸和碳水化合物的双功能手性叔胺硫脲。这些有机催化剂在室温下以良好的产率(高达 93%)和良好的对映选择性(高达 90% ee)促进了乙酰丙酮与各种芳香族和脂肪族硝基烯烃的对映选择性共轭加成。此外,公开了手性有机催化剂中两种不同手性单元的有趣匹配-错配效应。只需将溶剂从 THF 改为甲苯,就可以使用“匹配”和“错配”手性有机催化剂以几乎相同的对映体过量获得产物的两种对映体。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)