Quaternary ammonium ion dendrimers from methylation of poly(propylene imine)s

Abstract

The poly(propylene imine) dendrimers DAB‐dendr‐(NH2)8, DAB‐dendr‐(NH2)32, and DAB‐dendr‐(NH2)64 were fully converted with iodomethane to quaternary ammonium ions at both chain ends and branch points and, with less iodomethane, were partially converted to quaternary ammonium ions mainly at end groups. Amidation of the primary amine ends followed by treatment with iodomethane gave the first dendrimers with quaternary ammonium ions only at branch points. After an exchange of iodide counterions for chloride, all of the quaternary ammonium ion dendrimers slightly increased the rate of decarboxylation of 6‐nitrobenzisoxazole‐3‐carboxylate ion in an aqueous solution. Similar quaternary ammonium ion dendrimers with more hydrophobic interiors or more hydrophobic chains on the ends were much more active catalysts for the decarboxylation. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 821–832, 2001

Molecular dynamics of hydrophilic poly(propylene imine) dendrimers in aqueous solutions by 1H NMR relaxation

“…Three different PPI dendrimers with hydrophilic TEO terminal groups were synthesized from poly(propyleneimine) dendrimers diaminobutane (DAB)‐ dendr ‐(NH 2 ) n ( n = 8, 32, and 64 for generations 2, 4, and 5, respectively), as reported previously 28. They are denoted PPI(TEO) 8 , PPI(TEO) 32 , and PPI(TEO) 64 , respectively.…”

Dendrimers - Nanoparticles with Precisely Engineered Surfaces

“…The commercial availability of poly(propylene imine), ASTRAMOL™, dendrimers enabled numerous peripheral acylation studies with various acid chlorides [54][55][56][57][58][59][60][61][62][63][64][65][66], Scheme (10). The higher activity of the reagents in comparison to the previous substitution process allowed the incorporation of rather long (Scheme 10.1,4-6) or bulky (Scheme 10.2,3,7) fragments.…”

“…The higher activity of the reagents in comparison to the previous substitution process allowed the incorporation of rather long (Scheme 10.1,4-6) or bulky (Scheme 10.2,3,7) fragments. In most experiments [54][55][56][57][58][59][60][61][62][63][64][65][66] triethylamine was used as the base, but dimethylaminopyridine (DMAP) [56] and simple mixing [62,63] were mentioned, as well. The reaction of alkyl acid chlorides (Scheme 10.1) was studied in some detail by Meijer et al [54], who found that oleyl-and palmitoyl chlorides yield surprisingly only two product fractions -an almost fully (~95%) substituted and a completely unsubstituted ones when the dendrimers were used in 2-4 fold excess.…”

“…All dendrimers with peripheral long fatty acid residues behave like typical reversed micelles in solution and liquid crystals in a solid state. The reported investigations outline the usefulness of these compounds as phase-transfer agents for broad range of processes and applications [54,55,[58][59][60][61][62][63]66]. …”

Functionalizing the interior of dendrimers: Synthetic challenges and applications

“…One important contribution to this area was made by Ford and coworkers, [83][84][85][86] who investigated the catalytic activity of poly(propylene imine) dendrimers that carried quaternized internal ammonium ions. Furthermore, there is one report about the reduction of an aromatic nitro group within an extended linear fragment of a first-generation dendrimer.…”