Metal-free quinolylation of the primary amino groups of amino acid derivatives and peptides with dihydrooxazolo[3,2-a]quinoliniums

Abstract

A new metal-free method for the N-quinolylation of primary amino groups using novel dihydrooxazolo[3,2-a]quinoliniums showing good compatibility with other reactive moieties.

Chemo- and Site-Selective Lysine Modification of Peptides and Proteins under Native Conditions Using the Water-Soluble Zolinium

“…Recently, inspired by the chemical modification of primary amino groups in the n-butanol solution discovered in the structural optimization of berberine, 40 we designed and developed a panel of novel water-soluble zoliniums as covalent binders via introducing a sulfur or selenium atom in the critical reactive site. These newly developed warheads have been successfully used for selectively labeling lysine residue(s) of peptides/proteins under native conditions without any catalysts.…”

An aza-Diels–Alder route to quinoline-based unnatural amino acids and polypeptide surrogates

“…First, the described Povarov reaction-based approach to 2,4,6-substituted quinoline-based unnatural amino acid building blocks, which requires only 2 straightforward steps, mild reaction conditions, and commercially-available starting materials, may prove valuable from a methodology perspective with respect to those reported for the inspiring 2,4,8-substituted quinoline monomers. [26][27][28]31,32 Second, the validated solid support-based strategy affords polypeptide surrogates for which the repeating units resemble those of oligoamide foldamers [26][27][28]31,32 but the standard protein backbone resembles that of typical quinoline-decorated oligopeptides, 24,25 thus complementing the reported classes of macromolecules. Third, although the absorption spectra obtained for our quinoline-based polypeptide surrogates generally matched the ones reported for comparable quinoline-containing oligoamide foldamers, the uorescence spectra obtained for the surrogates revealed emission maxima that were blue-shied with respect to those found for the oligoamide foldamers, suggesting relatively weaker pi-pi stacking interactions among our surrogates' quinoline-based building blocks.…”

“…[1][2][3][4][21][22][23] Additionally, quinoline-decorated oligopeptides and quinoline-containing oligoamides have been frequently prepared via the conjugation of quinoline derivatives to amino acids or via the iterative coupling of small molecular building blocks on solid support. [24][25][26][27][28] These oligopeptides and oligoamides have exhibited various favorable characteristics, including sequence modularity, resistance to proteolytic degradation, ready cellular uptake, controllable conformational stability, and compatibility with a wide range of solvents. [28][29][30][31][32][33][34] Consequently, there has emerged an opportunity for the design and synthesis of alternative quinoline-based polypeptide surrogates that draw inspiration from the reported quinolinecontaining macromolecules.…”

Amino-based covalent organic frameworks for a wide range of functional modification

“…Amino-based compounds represent an important class of structural substances in the chemical industry and are considered key precursors and central intermediates for the construction of various functional molecules. [26][27][28] Due to their excellent ability to accept protons and donate electron pairs, amino groups could endow precursor molecules with a wide variety of physical, chemical and biological properties. [29][30][31][32] In particular, amino-functionalized porous materials have attracted great interest for potential applications such as catalysis, 33 separation, 24,34 and recognition.…”