19185-44-5Relevant academic research and scientific papers
Highly Diastereo- and Enantioselective Access to syn-α-Amido β-Hydroxy Esters via Ruthenium-Catalyzed Dynamic Kinetic Resolution-Asymmetric Hydrogenation
Lu, Bin,Wu, Xiaoyu,Li, Chengyang,Ding, Guangni,Li, Wanfang,Xie, Xiaomin,Zhang, Zhaoguo
, p. 3201 - 3213 (2019/03/11)
Dynamic kinetic resolution (DKR) of racemic aryl α-amino β-ketoesters via Ru-diphosphine-catalyzed asymmetric hydrogenation was realized at 70 °C under 50 atm of hydrogen, affording syn α-amido β-hydroxy esters in high yields (up to 96%) with high reactivity (TON up to 940) and diastereo- and enantioselectivities (up to 99:1 dr, 98% ee). These hydrogenation products provide valuable chiral synthons in many natural products and pharmaceuticals. Gram-scale DKR asymmetric hydrogenation (DKR-AH) was also performed with retained reactivity and stereoselectivity, revealing the synthetic utility of this method.
Rhodium-catalyzed asymmetric hydrogenation of tetrasubstituted β-acetoxy-α-enamido esters and efficient synthesis of droxidopa
Guan, Yu-Qing,Gao, Min,Deng, Xu,Lv, Hui,Zhang, Xumu
, p. 8136 - 8139 (2017/07/24)
A rhodium-catalyzed asymmetric hydrogenation of challenging tetrasubstituted β-acetoxy-α-enamido esters was developed, giving chiral β-acetoxy-α-amido esters in high yields with excellent enantioselectivities (up to >99% ee). The products could be easily transformed to β-hydroxy-α-amino acid derivatives which are valuable chiral building blocks and a novel route for the synthesis of droxidopa was also developed.
Stereoselective Lewis base-catalyzed asymmetric hydrosilylation of α-acetamido-β-enamino esters: Straightforward approach for the construction of α,β-diamino acid derivatives
Jiang, Yan,Chen, Xing,Hu, Xiao-Yan,Shu, Chang,Zhang, Yong-Hong,Zheng, Yong-Sheng,Lian, Chun-Xia,Yuan, Wei-Cheng,Zhang, Xiao-Mei
supporting information, p. 1931 - 1936 (2013/08/23)
The Lewis base-organocatalyzed asymmetric hydrosilylation of α-acetamido-β-enamino esters was investigated. Among various chiral Lewis base catalysts, a novel catalyst derived from L-serine was found to be the most efficient one which can promote the reaction to afford a series of α,β-diamino acid derivatives with high yields (up to 99%), excellent enantioselectivities (up to 98% ee) and moderate diastereoselectivities (up to 80:20 dr). The absolute configuration of one of the products was determined by the X-ray crystallographic analysis. In addition, the mechanism and the transition state of the reaction were proposed. Copyright
Pd-catalyzed enantioselective synthesis of quaternary α-amino acid derivatives using a phenylalanine-derived P-chirogenic diaminophosphine oxide
Nemoto, Tetsuhiro,Harada, Teisuke,Matsumoto, Takayoshi,Hamada, Yasumasa
, p. 6304 - 6307 (2008/02/10)
A Pd-catalyzed enantioselective synthesis of quaternary α-amino acid derivatives using a phenylalanine-derived P-chirogenic diaminophosphine oxide is described. Asymmetric allylic substitution using acyclic β-keto esters with a nitrogen functional group at the α-carbon as prochiral nucleophiles proceeded in the presence of 5 mol % of Pd catalyst, 10 mol % of chiral diaminophosphine oxide 1j, BSA, and appropriate additives, affording the corresponding quaternary α-amino acid derivatives in excellent yield and in up to 92% ee.
