Pyrrolidine

All solvents were purified before use. Ethyl chlorophormiate, pyrrolidine, morpholine, piperidine, acetophenone, ethyl oxalate, 2-acetylthiophene, and 2-acetylfurane were purchased from Acros Organics and used without purification. Reactions were monitored by thin-layer chromatography (TLC) using Fluka silica gel (60 F 254) plates (0.25 mm). Visualization was made with UV light. Melting points of the synthesized compounds were taken on a melting point tube. ¹H-NMR spectra were recorded on the Varian Gemini 400 MHz (Germany) in DMSO-d6 using tetramethylsilane (TMS) as an internal standard. Chemical shifts are reported in ppm units with use of the d scale. The mass spectra were recorded on an Agilent LC/MSD SL 1100 instrument (USA).

Acryloyl chloride (>97%, Sigma-Aldrich (Munich, Germany), contained 400 ppm phenothiazine as stabilizer, stored at 4 °C), anhydrous dichloromethane (DCM) (99.9%, extra dry, Acros Organics (Geel, Belgium)), 4,4′-azobis(4-cyanovaleric acid) (ACVA) (>98%, Sigma-Aldrich, stored at 4 °C), 2-(dodecylthiocarbonothioylthio)propionic acid (DTPA) (97%, Sigma-Aldrich, stored at 4 °C) and N,N-dimethylformamide (DMF) (>99.5%, VWR Chemicals (Darmstadt, Germany)) were used as received. Pyrrolidine (>99%, Acros Organics) and piperidine (99%, Acros Organics) were stored at 4 °C over molecular sieves (mesh size = 4 Å). Styrene (99%, Grüssing (Filsum, Germany), stored at 4 °C) and N,N-dimethylacrylamide (DMA) (99%, Sigma-Aldrich, stored at 4 °C) were freshly percolated through a column of basic alumina (>98%, Brockmann I, Sigma-Aldrich) prior to use to remove the inhibitor methyl ether hydroquinone. DOX (99%, Grüssing) was stored over KOH pellets (>85%, Merck (Darmstadt, Germany)) and freshly percolated through a basic alumina column prior to use to remove peroxides. Ultrapure water (MilliQ quality, resistivity >18.2 MΩ·cm⁻¹) was obtained from a Millipore (Darmstadt, Germany) MilliQ water purification system. All other chemicals were used as received in at least analytical grade.