Novel thiourea-amine bifunctional catalysts for asymmetric conjugate addition of ketones/aldehydes to nitroalkenes: rational structural combination for high catalytic efficiency
A series of thiourea-amine bifunctionalcatalysts have been developed by a rational combination of prolines with cinchona alkaloids, which are connected by a thiourea motif. The catalyst 3a, prepared from L-proline and cinchonidine, was found to be a highly efficient catalyst for the conjugateaddition of ketones/aldehydes to a wide range of nitroalkenes (up to 98/2 dr and 96% ee). The privileged cinchonidine
4-Aminothioureaprolinal dithioacetal 4a is a highlyefficientcatalyst for the asymmetric Michaeladdition of ketones and aldehydes to nitroolefins requiring only 3 mol-% catalyst loading. The reactions proceeded smoothly and gave syn selective adducts with excellent yields (up to 98 % yield), diastereoselectivity (up to >99:1 dr), and enantioselectivity (up to 99 % ee) under solvent free conditions
C3-Symmetric Proline-Functionalized Organocatalysts: Enantioselective Michael Addition Reactions
作者:Jarugu Narasimha Moorthy、Satyajit Saha
DOI:10.1002/ejoc.201000569
日期:2010.11
C 3 -Symmetric, tripodal catalyst 4 based on 1,3,5-triethylbenzene, which incorporates the features of a molecular receptor, is shown to catalyze Michaeladditionreactions of carbonyl compounds to β-nitrostyrenes in a high stereoselectivity (up to 99:1 dr and up to 98 % ee).
基于 1,3,5-三乙苯的 C 3 -对称三足催化剂 4 结合了分子受体的特征,显示出以高立体选择性(高达 99: 1 dr 和高达 98 % ee)。
l-Proline derived triamine as a highly stereoselective organocatalyst for asymmetric Michael addition of cyclohexanone to nitroolefins
作者:Haibin Chen、Yu Wang、Siyu Wei、Jian Sun
DOI:10.1016/j.tetasy.2007.05.035
日期:2007.6
triamine 4 has been developed as a highly efficient and stereoselective organocatalyst for the asymmetric Michaeladdition of cyclohexanone to nitroolefins. In the presence of (CF3SO2)2NH, 4 catalyzed the reaction of cyclohexanone to a variety of nitroolefins with high yields (up to 99%) and excellent diastereoselectivities (up to 99:1 dr) and enantioselectivities (up to 98% ee).
脯氨酸衍生的三胺4已被开发为一种高效且立体选择性的有机催化剂,用于环己酮向硝基烯烃的不对称迈克尔加成反应。在(CF 3 SO 2)2 NH存在下,4催化环己酮与各种硝基烯烃的反应,产率高(高达99%),非对映选择性(高达99:1 dr)和对映选择性(高达98)。 %ee)。
4-Fluoro and 4-Hydroxy Pyrrolidine-thioxotetrahydropyrimidinones: Organocatalysts for Green Asymmetric Transformations in Brine
作者:Nikolaos Kaplaneris、Giorgos Koutoulogenis、Marianna Raftopoulou、Christoforos G. Kokotos
DOI:10.1021/acs.joc.5b00283
日期:2015.6.5
The synthesis of both trans- and cis-diastereomers of pyrrolidinine-thioxotetrahydropyrimidinone bearing either a fluorine or a hydroxyl group was accomplished. The new compounds were tested for their catalytic properties in a variety of asymmetric organic transformations and compared with the first generation catalyst. It was found that the new catalysts could efficiently catalyze the reactions in