Dosage delivery of sensitive reagents enables glove-box-free synthesis

Contemporary organic chemists employ a broad range of catalytic and stoichiometric methods to construct molecules for applications in the material sciences, and as pharmaceuticals, agrochemicals, and sensors. The utility of a synthetic method may be greatly reduced if it relies on a glove box to enable the use of air- and moisture-sensitive reagents or catalysts. Furthermore, many synthetic chemistry laboratories have numerous containers of partially used reagents that have been spoiled by exposure to the ambient atmosphere. This is exceptionally wasteful from both an environmental and a cost perspective. Here we report an encapsulation method for stabilizing and storing air- and moisture-sensitive compounds. We demonstrate this approach in three contexts, by describing single-use capsules that contain all of the reagents (catalysts, ligands, and bases) necessary for the glove-box-free palladium-catalysed carbon-fluorine, carbon-nitrogen, and carbon-carbon bond-forming reactions. This strategy should reduce the number of error-prone, tedious and time-consuming weighing procedures required for such syntheses and should be applicable to a wide range of reagents, catalysts, and substrate combinations.National Science Foundation (U.S.) (Pre-doctoral fellowship (1122374))National Institutes of Health (U.S.) (Postdoctoral fellowship (1F32GM108092-01A1))National Institutes of Health (U.S.) (Award number R01GM46059

A facile method for the controlled polymerization of biocompatible and thermoresponsive oligo(ethylene glycol) methyl ether methacrylate copolymers

Photochemically controlled ATRP-like polymerization is successfully used to prepare a thermoresponsive copolymer of oligo(ethylene glycol) methyl ether methacrylate (OEGMA) and di(ethylene glycol) methyl ether methacrylate (MEO2MA). The photochemically controlled method described here provides good control over the polymer structure, architecture, and properties. This photopolymerization renders polymers with narrow molecular weight distributions (Mw/Mn = 1.3) and high monomer conversions (>90%) while using a very low iridium-based catalyst concentration (25 ppm). In addition, the reaction rate of this polymerization is fast, reaching 50% monomer conversion in less than 1 h of reaction. The lower critical solution temperature (LCST) of the prepared polymer was also adjusted to be in the range of physiological temperatures, undergoing a coil-to-globule transition at 43 °C. In addition, the resulting polymer showed no cytotoxicity on four mammalian cell lines at the highest concentration tested (0.4 mg/ml), which highlights its potential use in different biomedical applications.We thank the ERC Consolidator Grant program (ERC-2013- CoG-614715, NANOHEDONISM) for the financial support. CIBER-BBN is an initiative funded by the VI National R&D&i Plan 2008–2011 financed by the Instituto de Salud Carlos III with the assistance of the European Regional Development Fund.Peer reviewe