Nicolas Illy

Phosphorylation of bio-based compounds: the state of the art

Over the last few years, more and more papers have been devoted to phosphorus-containing polymers, mainly due to their fire resistance, excellent chelating and metal-adhesion properties. Nevertheless, sustainability, reduction of environmental impacts and green chemistry are increasingly guiding the development of the next generation of materials. The use of bio-based polymer matrices might allow the reduction of environmental impacts by using renewable carbon and by achieving more easily biodegradable or reusable materials. The aim of this review is to present both fundamental and applied research on the phosphorylation of renewable resources, through reactions on naturally occurring functions, and their use in biobased polymer chemistry and applications. In the first section, different strategies for the introduction of phosphorus-containing functions on organic backbones are described. In the following sections, the main families of chemicals based on renewable resources are covered: namely polysaccharides (cellulose, chitosan, starch, dextran etc.), biophenols (lignins, biobased phenolic compounds, cardanol etc.), triglycerides (oils, glycerol) and hydroxy acid compounds.

Metal-chelating polymers by anionic ring-opening polymerization and their use in quantitative mass cytometry.

Metal-chelating polymers (MCPs) are important reagents for multiplexed immunoassays based on mass cytometry. The role of the polymer is to carry multiple copies of individual metal isotopes, typically as lanthanide ions, and to provide a reactive functionality for convenient attachment to a monoclonal antibody (mAb). For this application, the optimum combination of chain length, backbone structure, end group, pendant groups, and synthesis strategy has yet to be determined. Here we describe the synthesis of a new type of MCP based on anionic ring-opening polymerization of an activated cyclopropane (the diallyl ester of 1,1-cyclopropane dicarboxylic acid) using a combination of 2-furanmethanethiol and a phosphazene base as the initiator. This reaction takes place with rigorous control over molecular weight, yielding a polymer with a narrow molecular weight distribution, reactive pendant groups for introducing a metal chelator, and a functional end group with orthogonal reactivity for attaching the polymer to the mAbs. Following the ring-opening polymerization, a two-step transformation introduced diethylenetriaminepentaacetic acid (DTPA) chelating groups on each pendant group. The polymers were characterized by NMR, size exclusion chromatography (SEC), and thermogravimetric analysis (TGA). The binding properties toward Gd(3+) as a prototypical lanthanide (Ln) ion were also studied by isothermal titration calorimetry (ITC). Attachment to a mAb involves a Diels-Alder reaction of the terminal furan with a bismaleimide, followed by a Michael addition of a thiol on the mAb, generated by mild reduction of a disulfide bond in the hinge region. Polymer samples with a number average degree of polymerization of 35, with a binding capacity of 49.5 ± 6 Ln(3+) ions per chain, were loaded with 10 different types of Ln ions and conjugated to 10 different mAbs. A suite of metal-tagged Abs was tested by mass cytometry in a 10-plex single cell analysis of human adult peripheral blood, allowing us to quantify the antibody binding capacity of 10 different cell surface antigens associated with specific cell types.

Metal-Free Activation in the Anionic Ring-Opening Polymerization of Cyclopropane Derivatives

The successful activation observed when using Bu(t) P(4) phosphazene base and thiophenol or bisthiols for the anionic ring opening polymerization (ROP) of di-n-propyl cyclopropane-1,1-dicarboxylate is described. Well-defined monofunctional or difunctional polymers with a very narrow molecular weight distribution were obtained through a living process. Quantitative end-capping of the propagating malonate carbanion was accessible by using either an electrophilic reagent such as allyl bromide or a strong acid such as HCl. Kinetics studies demonstrated a much higher reactivity compared to the conventional route using alkali metal thiophenolates.

A Chitosan Derivative Containing Both Carboxylic Acid and Quaternary Ammonium Moieties for the Synthesis of Cyclic Carbonates

Chitosan, a renewable feedstock, is modified and used as a catalytic support in the presence of potassium iodide. The system is highly efficient towards the incorporation of carbon dioxide (CO2 ) into epoxides. It demonstrates very good thermal stability and is recyclable more than five times without loss of activity. The optimal reaction conditions were determined using allylglycidyl ether as a model and extended to a wide range of other epoxides. Cyclic carbonates were obtained with very high yield in a few hours under mild conditions (2-7 bar≈0.2-0.7 MPa, 80 °C) and no solvent.

Phosphazene/triisobutylaluminum-promoted anionic ring-opening polymerization of 1,2-epoxybutane initiated by secondary carbamates

Attempts to use a carbamate-phosphazene base as the initiating system for the polymerization of 1,2-epoxybutane was unsuccessful. As a matter of fact, carbamate deprotonation by phosphazene bases led to their fast decomposition generating alkoxide anions which initiate the polymerization rather than carbamate anions. Conversely, in the presence of triisobutylaluminum – a Lewis acid – the in situ generation of an anionic initiator X− obtained by the deprotonation of the tBuP4 phosphazene base was tested as a possible way to initiate the polymerization of 1,2-epoxybutane. Particular attention was given to the detection of eventual transfer or side-reactions according to the carbamate : triisobutylaluminum : phosphazene base ratio, to the solvent dielectric constant and to the number of PN– units in the phosphazene base. The reaction was performed with a stoichiometric ratio (1 : 1 : 1) of carbamate : triisobutylaluminum : tBuP2, which gave the best results. Under these conditions, the initiation of the polymerization by the carbamate anion was quantitative; no transfer reactions have been observed and the polymerization proceeded in a controlled manner to afford amide end-capped poly(butylene oxide) with a narrow molar mass distribution and expected molar masses.

A polymeric membrane permeabilizer displaying densely packed arrays of crown ether lateral substituents

We report the design, synthesis and evaluation of a novel macromolecular membrane permeabilizer displaying geminally substituted crown-ethers (18-crown-6) on every third carbon alongside the backbone. The polymer has a rather high affinity with potassium as well as permeabilization properties towards K+, Na+ and Ca2+, including single-channel behavior.

Correction: Phosphorylation of bio-based compounds: the state of the art

Correction for ‘Phosphorylation of bio-based compounds: the state of the art’ by Nicolas Illy, et al., Polym. Chem., 2015, 6, 6257–6291.