Highly enantio- and diastereoselective Michael addition of cyclohexanone to nitroolefins catalyzed by a chiral glucose-based bifunctional secondary amine-thiourea catalyst
A novel bifunctional thiourea bearing a saccharide-scaffold and a secondary amino group was synthesized, and was proven to be an effective organocatalyst for the asymmetric Michael reaction of cyclohexanone to both aryl and alkyl nitroolefins. The corresponding adducts were obtained with excellent diastereo- (up to >99/1 dr) and enantioselectivities (up to 97% ee).
chiral thiophosphoramide to afford exclusively the thermodynamically favoured diastereomer. This novel secondary amine-thiophosphoramide has proven to be an effective bifunctional organocatalyst for the asymmetric Michaeladdition of cyclohexanone to both aryl- and alkyl-substituted nitroolefins. The corresponding adducts were obtained with excellent diastereo- (up to >99:1 dr) and enantioselectivities
A novel type of pyrrolidine-based chiral (thio)phosphoramidates was synthesized. Among them, compound (S,aR)-3d was proven to be an effective bifunctional organocatalyst for the asymmetric Michaeladdition of ketones to nitroolefins. The corresponding adducts were obtained in good to excellent chemical yields with high levels of diastereo- and enantioselectivities (up to >99:1 dr and 99 % ee).
合成了一种新型的基于吡咯烷的手性(硫代)氨基磷酸酯。其中,化合物 (S,aR)-3d 被证明是一种有效的双功能有机催化剂,用于酮与硝基烯烃的不对称迈克尔加成。相应的加合物以良好到优异的化学产率获得,具有高水平的非对映选择性和对映选择性(高达 >99:1 dr 和 99% ee)。
Synthesis of Binaphthyl Sulfonimides and Their Application in the Enantioselective Michael Addition of Ketones to Nitroalkenes
作者:Shurong Ban、Da-Ming Du、Han Liu、Wen Yang
DOI:10.1002/ejoc.201000818
日期:2010.9
types of L -proline-based binaphthylsulfonimides and sulfonamides were found to be efficient organocatalysts for the asymmetric Michaeladdition of ketones to nitroalkenes to provide optically active γ-nitroketone derivatives of synthetic and biological importance. After the fine optimization of solvents, temperature, and additive, good to excellent enantioselectivities and diastereoselectivities
Highly Enantioselective Michael Addition of Ketones to Nitroolefins with a Pyrrolidine-Based Phthalimide as an Enamine-Type Organocatalyst
作者:Shu-rong Ban、Hong-yu Xie、Xi-xia Zhu、Qing-shan Li
DOI:10.1002/ejoc.201101093
日期:2011.11
new type of pyrrolidine-based phthalimide and otheranalogous imide catalysts 5a–c were found to be efficient organocatalysts for the asymmetric Michael reaction of ketones to nitroalkenes. After fine optimization of solvents, temperature, and the additive, good to excellent enantioselectivities and diastereoselectivities (up to 99 % ee, up to >99:1 dr) can be achieved.