15329-69-8Relevant articles and documents
"one-Pot" Aminolysis/Thiol-Maleimide End-Group Functionalization of RAFT Polymers: Identifying and Preventing Michael Addition Side Reactions
Abel, Brooks A.,McCormick, Charles L.
, p. 6193 - 6202 (2016)
We show that many of the nucleophiles (catalysts, reducing agents, amines, thiols) present during "one-pot" aminolysis/thiol-maleimide end-group functionalization of RAFT polymers can promote side reactions that substantially reduce polymer end-group functionalization efficiencies. The nucleophilic catalyst 1,8-diazabicyclo[5.4.0]undec-7-ene and the reducing agent tributylphosphine were shown to initiate anionic polymerization of N-methylmaleimide (NMM) in both polar and nonpolar solvents whereas hexylamine-initiated polymerization of NMM occurred only in high-polarity solvents. Furthermore, triethylamine-catalyzed Michael reactions of the representative thiol ethyl 2-mercaptopropionate (E2MP) and NMM in polar solvents resulted in anionic maleimide polymerization when [NMM]0 > [E2MP]0. Base-catalyzed enolate formation on the α-carbon of thiol-maleimide adducts was also shown as an alternative initiation pathway for maleimide polymerization in polar solvents. Ultimately, optimal "one-pot" reaction conditions were identified allowing for up to 99% maleimide end-group functionalization of dithiobenzoate-terminated poly(N,N-dimethylacrylamide). Much of the work described herein can also be used to ensure near-quantitative conversion of small molecule thiol-maleimide reactions while preventing previously unforeseen side reactions.
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Mehta,N.B. et al.
, p. 1012 - 1015 (1960)
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Dichloro Butenediamides as Irreversible Site-Selective Protein Conjugation Reagent
Abegg, Daniel,Adibekian, Alexander,Afonso, Cláudia F.,Bernardes, Gon?alo J. L.,Corzana, Francisco,Laserna, Victor,Martin, Esther M.,Ravn, Peter
supporting information, p. 23750 - 23755 (2021/10/01)
We describe maleic-acid derivatives as robust cysteine-selective reagents for protein labelling with comparable kinetics and superior stability relative to maleimides. Diamide and amido-ester derivatives proved to be efficient protein-labelling species with a common mechanism in which a spontaneous cyclization occurs upon addition to cysteine. Introduction of chlorine atoms in their structures triggers ring hydrolysis or further conjugation with adjacent residues, which results in conjugates that are completely resistant to retro-Michael reactions in the presence of biological thiols and human plasma. By controlling the microenvironment of the reactive site, we can control selectivity towards the hydrolytic pathway, forming homogeneous conjugates. The method is applicable to several scaffolds and enables conjugation of different payloads. The synthetic accessibility of these reagents and the mild conditions required for fast and complete conjugation together with the superior stability of the conjugates make this strategy an important alternative to maleimides in bioconjugation.
