Novel chiral hydrogen bond donor catalysts based on a 4,5-diaminoxanthene scaffold: application to enantioselective conjugate addition of 1,3-dicarbonyl compounds to nitroalkenes
Novelchiral hydrogen bond donor catalysts based on a 4,5-diamino-9,9′-dimethylxanthene skeleton were designed and synthesized. Among the phenylurea-amide hybrid molecules prepared from various natural/unnatural chiral amino acids, the phenylalanine-derived catalyst, and the proline-derived catalyst were successfully applied to enantioselective conjugate addition of 1,3-dicarbonyl compounds to nitroalkenes
Threonine-derived thioureas as bifunctional organocatalysts for enantioselective Michael addition
作者:Zhi Zheng、Jian Lin、Yang Sun、Suoqin Zhang
DOI:10.1016/j.tetlet.2019.151382
日期:2020.1
A series of threonine-derived thioureas were developed through the facile modification of L-threonine chiral scaffold. The enantioselective efficiency were evaluated in the catalytic asymmetric Michaeladdition of 2-hydroxy-1,4-naphthoquinone to nitroalkenes, which afforded the chiral nitroalkylated naphthoquinone derivatives in high yields (up to 93%) and enantio-selectivities (up to 99% ee) under
Noyori's Ts-DPEN Ligand: Simple yet Effective Catalyst for the Highly Enantioselective Michael Addition of Acetone to Nitroalkenes
作者:Lin Peng、Xiao-Ying Xu、Liang-Liang Wang、Jun Huang、Jian-Fei Bai、Qing-Chun Huang、Li-Xin Wang
DOI:10.1002/ejoc.200901509
日期:2010.4
HighlyenantioselectiveMichaeladdition of acetone to a variety of nitroalkenes promoted by simple chiral primary amine bifunctional catalysts (e.g., Noyori's Ts-DPEN ligand) together with terephthalic acid in excellent yields (84-99 %) and enantioselectivities (93―98 % ee) is reported.
Aminochlorination reaction with N-chlorophthalimide as a new nitrogen/chlorine source resulting in α-amino derivatives
作者:Yu Qian、Xiaoyun Ji、Wei Zhou、Jianlin Han、Guigen Li、Yi Pan
DOI:10.1016/j.tet.2012.05.066
日期:2012.8
N-chlorophthalimide was reported as an efficient nitrogen/chlorine source for the aminohalogenation of β-nitrostyrenes, which tolerates a wide range of β-nitrostyrenes substrates with good chemical yields, as well as excellent regioselectivities. The resulted vicinal haloamino nitro products have been converted into several other valuable α-amino compounds under simple and mild conditions.
Potassium Carbonate Catalyzed Regioselective Aminohalogenation of β-Nitrostyrenes by Using Benzyl Carbamate/N-Chlorosuccinimide as a New Nitrogen/Chlorine Source
作者:Jianlin Han、Yi Pan、Xiaoyun Ji、Haibo Mei、Yu Qian、Guigen Li
DOI:10.1055/s-0030-1260245
日期:2011.11
A combination of benzyl carbamate and N-chlorosuccinimide was developed as a new system for aminohalogenation of β-nitrostyrenes catalyzed by potassium carbonate in dichloromethane at room temperature. The reaction tolerates a wide range of substituents on the β-nitrostyrene, and proceeds smoothly in good-to-excellent chemical yields (77-99%). The new system shows a high efficiency and it markedly