Preparative hydrophilic interaction liquid chromatography of acidic organofluorophosphates formed in lithium ion battery electrolytes.

The expansion of lithium ion battery (LIB) application is accompanied by the growth of battery pack sizes. This progression emphasizes the consideration of electrolyte safety as well as environmental aspects in case of abuse, accident, or recycling. Hexafluorophosphate is one of the most commonly used conducting salt anions in electrolytes. It has great potential to degrade to various acidic and non-acidic organo(fluoro)phosphates with presence of water and during battery cell operation. Consequently, toxicological investigation on these organo(fluoro)phosphates has emerged because they either have structural similarities as chemical warfare agents or play a widespread physiological role as phosphates in the human body. This circumstance underlines the need of isolated examination of these compounds for safety assessment. In this work, we used hydrophilic interaction liquid chromatography for the extraction of acidic organofluorophosphates from thermally aged LIB electrolytes. The developed two-step fractionation method provided high separation selectivity towards acidic head groups, which allowed the separation of undesired matrix and target compounds. These findings facilitate isolated toxicological investigations on organofluorophosphates that are beneficial for environmental and safety research, the battery cell industry, and human safety surveillance in regard to aged LIB electrolytes.

Rapid one-step 18F-radiolabeling of biomolecules in aqueous media by organophosphine fluoride acceptors.

Currently, only a few 18F-radiolabeling methods were conducted in aqueous media, with non-macroelement fluoride acceptors and stringent conditions required. Herein, we describe a one-step non-solvent-biased, room-temperature-driven 18F-radiolabeling methodology based on organophosphine fluoride acceptors. The high water tolerance for this isotope-exchange-based 18F-labeling method is attributed to the kinetic and thermodynamic preference of F/F over the OH/F substitution based on computational calculations and experimental validation. Compact [18/19F]di-tert-butyl-organofluorophosphine and its derivatives used as 18F-labeling synthons exhibit excellent stability in vivo. The synthons are further conjugated to several biomolecular ligands such as c(RGDyk) and human serum albumin. The one-step labeled biomolecular tracers demonstrate intrinsic target imaging ability and negligible defluorination in vivo. The current method thus offers a facile and efficient 18F-radiolabeling pathway, enabling further widespread application of 18F.

Covalent and selective immobilization of GST fusion proteins with fluorophosphonate-based probes.

Using GST fusion protein tags is an attractive approach for protein immobilization. Here we report that pyrimidine-based small-molecule probes with a fluorophosphonate reactive group could specifically react with the tyrosine-111 residue of the Schistosoma japonicum GST (sjGST) tag, and these probes could rapidly and site-selectively immobilize sjGST fusion proteins while preserving their activities.

Pd-catalyzed highly regio-, diastereo-, and enantioselective allylic alkylation of α-fluorophosphonates.

Highly efficient Pd-catalyzed asymmetric allylic alkylation reaction of ethyl-2-fluoro-2-(diethoxyphosphoryl)acetate with monosubstituted allylic substrates has been developed, affording corresponding α-fluorophosphonates with two chiral centers in high regio-, diastereo- and enantio-selectivities. The usefulness of the products in organic synthesis has been demonstrated.