Heteroarylalanines

Synthesis of Heterocycles from Alkyl 3-(Dimethylamino)propenoates and Related Enaminones

“…In the past few decades, several synthetic methods for the preparation of 3-heteroarylalanines have been developed due to their occurrence in nature, biological activity, and synthetic applicability. 142 Among various synthetic approaches, transformations of commercially available R-amino acids, such as serine, aspartic acid, and glutamic acid, found a wide applicability in the preparation of 3-heteroarylalanines. [143][144][145][146][147][148][149][150][151] Recently, Young and co-workers reported the synthesis of 3-(pyrazolyl)-, 3-(isoxazolyl)-, and 3-(pyrimidinyl)alanines from (S)-3-formylpyroglutamic acid derivatives, using a ring switching strategy.…”

“…In the past few decades, several synthetic methods for the preparation of 3-heteroarylalanines have been developed due to their occurrence in nature, biological activity, and synthetic applicability . Among various synthetic approaches, transformations of commercially available α-amino acids, such as serine, aspartic acid, and glutamic acid, found a wide applicability in the preparation of 3-heteroarylalanines. − Recently, Young and co-workers reported the synthesis of 3-(pyrazolyl)-, 3-(isoxazolyl)-, and 3-(pyrimidinyl)alanines from ( S )-3-formylpyroglutamic acid derivatives, using a ring switching strategy. − On the other hand, our previous study on the chemistry of polyfunctionalized alkyl 2-substituted 3-(dimethylamino)propenoates showed that this type of compound can serve as a versatile, simple, and efficient synthetic tool for the preparation of a variety of heterocyclic systems, α,β-dehydro-α-amino acid derivatives, and peptides, as well as N -protecting reagents in the peptide synthesis. − In this connection, we introduced 5-substituted ( S )-1-acyl-3-[( E )-(dimethylamino)methylidene]pyrrolidin-2-ones 24 and ( S )-3-[( E )-(dimethylamino)methylidene]tetrahydrofuran-2-ones 25 , which can be prepared in two steps from commercially available precursors. − Analogously to acyclic alkyl 3-(dimethylamino)propenoates, enamino lactams 24 and lactones 25 show ambident 1,3-dielectrophilic behavior, due to electrophilic reactive sites at positions C (3‘)-NMe 2 and C (2)O with the following order of reactivity: C (3‘)-NMe 2 > C (2)O.…”

Copper-Promoted Double Oxidative C–H Amination Cascade for the Synthesis of Imidazo[1,5-a]quinolines

“…Imidazo­[1,5- a ]­quinolines are an important class of fused N-heterocyclic compounds due to their wide applications in medicinal chemistry (e.g., NK1 receptor ligands) . A great deal of attention has been paid to synthesize imidazo­[1,5- a ]­quinoline derivatives . The most popular strategy for the synthesis of imidazo­[1,5- a ]­quinolines is Vilsmeier-type cyclizations, which involved the use of N -2-pyridylmethylamides as substrates .…”

Hexafluoroacetone as Protecting and Activating Reagent: New Routes to Amino, Hydroxy, and Mercapto Acids and Their Application for Peptide and Glyco- and Depsipeptide Modification

“…Likewise, 3-(selenazol-4-yl)-2-aminopropionic acid derivatives have been prepared by this route (Scheme ) . 3-(Thiazol-4-yl)-2-aminopropionic and -2-hydroxypropionic acids are pharmacologically relevant heteroarylalanines 40 …”