α-Amino Acids as Synthons in the Ugi-5-Centers-4-Components Reaction: Chemistry and Applications

Abstract

Since the first reports, the Ugi four-component reaction (U-4CR) has been recognized as a keystone transformation enabling the synthesis of peptide mimetics in a single step and with high atom economy. In recent decades, the U-4CR has been a source of inspiration for many chemists fascinated by the possibility of identifying new efficient organic reactions by simply changing one of the components or by coupling in tandem the multicomponent process with a huge variety of organic transformations. Herein we review the synthetic potentialities, the boundaries, and the applications of the U-4CR involving α-amino acids, where the presence of two functional groups—the amino and the carboxylic acids—allowed a 5-center 4-component Ugi-like reaction, a powerful tool to gain access to drug-like multi-functionalized scaffolds.

Effects of Zinc Substitution on the Microstructural and Magnetic Characteristics of Cubic Symmetry Nickel Ferrite System

“…In other words, the overall magnetization of the Zn substituted nickel ferrite increases although a decrease of the magnetic moment at A-sites due to the Zn 2+ ions occupying these sites. However, the substitution of Ni by Zn in order to synthesis of the substituted nickel ferrite using glycine-assisted combustion method resulted in presence of the Zener double exchange (ZDE) mechanism leading to enhanced hole density [31,32]. This is due to the presence of Fe 2+ ions with Fe 3+ cations at B-sites.…”

Ugi Four-Component Reactions Using Alternative Reactants

“…In continuation of the breathtaking research mentioned above, natural and unnatural-amino acids, due to having both a primary amine and a carboxylic acid functional group, could be considered as privileged synthons for a three-component Ugi-reaction [ 47 ]. Ugi reaction of natural amino acids has meanwhile been deployed for structurally diverse polypeptoid as a direct and effective method [ 48 ].…”

Two decades of recent advances of Ugi reactions: synthetic and pharmaceutical applications

“…Similarly, the Ugi reaction between axisonitrile-3 83 acetone 85 and glutamic acid 84 was the key step in the biosynthesis of boneratamide A 83 (Scheme 20). 13,53,54 Pacidamycin D 90, a member of a class of uridylpeptide antibiotics, was rst isolated from Streptomyces coeruleorubidus AB 1183F-64 in 1989. 55 The analogues of pacidamycin D 90 are 3 0 -hydroxypacidamycin D 91 (Fig.…”