133445-97-3Relevant academic research and scientific papers
Diastereoselective Synthesis of Substituted Glutamic Acid Derivatives via Michael Additions of N-glycinates under Solid-Liquid Phase Transfer Catalysis
Alvarez-Ibarra, Carlos,Csaky, Aurelio G.,Maroto, Mercedes,Quiroga, M. Luz
, p. 6700 - 6705 (1995)
Michael additions of the enolates of ethyl and tert-butyl N-glycinates with α,β-unsaturated esters and ketones under solid-liquid phase transfer catalysis allowed for the highly diastereoselective synthesis of substituted glutami
Enantioselective Synthesis of Pyroglutamic Acid Esters from Glycinate via Carbonyl Catalysis
Ma, Jiguo,Zhou, Qinghai,Song, Guanshui,Song, Yongchang,Zhao, Guoqing,Ding, Kuiling,Zhao, Baoguo
supporting information, p. 10588 - 10592 (2021/04/06)
Direct α-functionalization of NH2-free glycinates with relatively weak electrophiles such as α,β-unsaturated esters still remains a big challenge in organic synthesis. With chiral pyridoxal 5 d as a carbonyl catalyst, direct asymmetric conjugated addition at the α-C of glycinate 1 a with α,β-unsaturated esters 2 has been successfully realized, to produce various chiral pyroglutamic acid esters 4 in 14–96 % yields with 81–97 % ee's after in situ lactamization. The trans and cis diastereomers can be obtained at the same time by chromatography and both of them can be easily converted into chiral 4-substituted pyrrolidin-2-ones such as Alzheimer's drug Rolipram (11) with the same absolute configuration via tert-butyl group removal and subsequent Barton decarboxylation.
Multicomponent synthesis of pyroglutamic acid derivatives: Via Knoevenagel-Michael-hydrolysis-lactamization-decarboxylation (KMHL-D) sequence
Khopade, Tushar M.,Warghude, Prakash K.,Sonawane, Amol D.,Bhat, Ramakrishna G.
supporting information, p. 561 - 566 (2019/01/24)
A novel and practical method for the synthesis of 3-substituted pyroglutamic acid derivatives is described. One pot multicomponent reaction of Meldrum's acid, aldehyde and Schiff's base followed an unprecedented chemoselective Knoevenagel-Michael-hydrolysis-lactamization domino sequence to afford 4-carboxy 3-substituted pyroglutamic acid derivatives under mild conditions. A carboxy intermediate formed appears to accelerate its own formation. The generality of the synthesis is exemplified by the use of a wide variety of aldehydes including enolizable aliphatic aldehydes, while substrates are stable under reaction conditions.
Highly Diasteroselective Michael-Addition of Lithiated Camphor Imines of Glycine Esters to α,β-Unsaturated Esters. Synthesis of Optically Pure 5-Oxo-2,4-pyrrolidinedicarboxylates of Unnatural Stereochemistry
Kanemasa, Shuji,Tatsukawa, Akira,Wada, Eiji
, p. 2875 - 2883 (2007/10/02)
The lithium enolates of camphor imines of glycine esters underwent highly diastereoselective Michael additions to the α,β-unsaturated esters.The tightly chelated structure of the Z,E enolates and the selective approach of the α,β-unsaturated esters to the
