On the structure–control relationship of amide-functionalized SG1-based alkoxyamines for nitroxide-mediated polymerization and conjugation

Abstract

Investigation on the reactivity and the controlling ability of a series of amide-functionalized alkoxyamines based on the SG1 nitroxide is reported.

Degradable polymer prodrugs with adjustable activity from drug-initiated radical ring-opening copolymerization

“…Conversely to Gem-digly-AMA-SG1, Gem-AMA-SG1 is prone to intramolecular hydrogen-bonding (IHB) between the hydrogen of the amide from the propagating radical and the nitroxide fragment. 63 It resulted in slower dissociation kinetics and thus a less efficient control because of the lower amount of released nitroxide.…”

Dual-initiator alkoxyamines with an N-tert-butyl-N-(1-diethylphosphono-2,2-dimethylpropyl) nitroxide moiety for preparation of block co-polymers

“…1), which carries a carboxylic function on its alkyl moiety and is one of the most efficient initiators of NMP, both the high lability of 1 and the neopentylic carboxy function preclude easy and straightforward use as a dual initiator. 19 This drawback has been circumvented by either activation of the carboxylic function for graing of a polymer chain 19,20 or by means of intermolecular radical 1,2-addition on an activated alkene. 21 As far as we know, there is only one report on the esterication of 1 using the carboxylate function.…”

Responsive hybrid (poly)peptide–polymer conjugates

“…Different polymerization techniques such as atom transfer radical polymerization (ATRP), 26–30 reversible addition-fragmentation chain transfer polymerization (RAFT), 29,31 nitroxide mediated polymerization (NMP), 29,32–35 opening metathesis polymerization (ROMP), 17,36–39 and ring opening polymerization (ROP), 40–42 have facilitated the development of tailor-made polymers that possess predictable molecular weight and narrow molecular weight distributions. The properties of the controlled polymers can then be further enhanced via conjugation of (poly)peptides to tune hierarchical assembly, stimuli response or desired targeting (Figure 2).…”

“…For instance, amide-functionalized alkoxyamines (a functionality often obtained after conjugation from COOH– and N-succinimidyl-containing alkoxyamines) based on the nitroxide SG1 (N-tert-butyl-N-(1-diethyl phosphono-2,2-dimethylpropyl) nitroxide) have been synthesized. 32,33 In another approach, peptide–polymer conjugates were produced via a solid-support method involving both step-growth and chain-growth polymerization mechanisms. An amphiphilic triblock copolymer consisting of a protein transduction domain (PTD) peptide, poly(acrylic acid), and poly(methyl acrylate) (PTD- b -PAA- b -PMA) were prepared using this approach.…”