Synthesis of sugar-substituted cyclic and polymeric phosphazenes and their oxidation, reduction, and acetylation reactions

Abstract

Sugar residues have been linked to cyclic and high-polymeric phosphazenes. Selective blocking of the 1,2-and 5,6-hydroxyl groups of -D-glucose by acetone allowed linkage to the phosphazene via the remaining hydroxyl unit. Hydrolysis of the blocked, sugar-substituted phosphazenes brought about deprotection. The deprotected derivatives were then modified chemically by oxidation, reduction, and acetylation. The resultant high polymers are the first members of a new class of hydrophilic or water-soluble macromolecules. Their properties and structural characterization are discussed.

Expanding Options in Polyphosphazene Biomedical Research

“…5. Secondary substitution reactions carried out on the organic side groups introduced by one of the preceding methods [37][38][39][40][41][42].…”

Synthesis of Polyphosphazene Derivatives via Thiol‐ene Click Reactions in an Aqueous Medium

“…[ 18,19 ] The unique feature of polyphosphazene science is the ease of macromolecular substitution, where chlorine atoms on a precursor polymer consisting of polydichlorophosphazene can be substituted by various nucleophiles. [20][21][22][23][24][25][26][27] The substituent groups attached to the phosphorous atoms endow polyphosphazenes with different physical and chemical characteristics, thus producing materials that can be applied to a wide range of applications. By defi nition, such a macromolecular substitution reaction is a kind of post-polymerization modifi cation.…”

“Click Chemistry” as a Facile Approach to the Synthesis of Polyphosphazene Glycopolymers

“…[7][8][9][10][11][12][13][14][15] Polyphosphazene derivatives with carbohydrates as side groups are of particular interest for probes or effectors in biological processes involving carbohydrate/protein interactions. [16][17][18][19][20][21][22][23] For example, Heyde et al introduced galactose to polyphosphazene using either 6-aminohexanol or poly(ethylene glycol) as a spacer, and demonstrated that the galactose pendants were able to selectively bind lectin. A large proportion of galactose was favorable for multivalent carbohydrate/protein interactions.…”

“…To form polyphosphazene glycopolymer with a high degree of substitution, Allcock et al synthesized a single substituent a-D-glucosylphosphazene by the reaction of the sodium salt of diacetone-Dglucose with poly(dichlorophosphazene) using the ''protection/deprotection'' method. [16] However, the process was limited by the steric hindrance effect associated with the bulky diacetone-D-glucosy1 group, and replacement of the last 10-15% of chlorine atoms was exceedingly difficult. [17] Furthermore, the unreacted P-Cl units could eventually lead to general breakdown of the polymer backbones or generate crosslinking by reaction with the hydroxyl groups of glucose pendants.…”