This work presents a detailed computational study and kinetic analysis of the aza-Michael addition of primary and secondary amines to acrylates in an aprotic solvent. Accurate rate coefficients for all elementary steps in the various competing mechanisms are calculated using an ONIOM-based approach in which the full system is calculated with M06-2X/6-311+G(d,p) and the core system with CBS-QB3 corrected for solvation using COSMO-RS. Diffusional contributions are taken into account using the coupled encounter pair model with diffusion coefficients calculated based on molecular dynamics simulations. The calculated thermodynamic and kinetic parameters for all forward and reverse elementary reactions are fed to a microkinetic model giving excellent agreement with experimental data obtained using GC analysis. Rate analysis reveals that for primary and secondary amines, the aza-Michael addition to ethyl acrylate occurs preferentially according to a 1,2-addition mechanism, consisting of the pseudoequilibrated formation of a zwitterion followed by a rate controlling amine assisted proton transfer toward the singly substituted product. The alternative 1,4-addition becomes competitive if substituents are present on the amine or double bond of the acrylate. Primary amines react faster than secondary amines due to increased solvation of the zwitterionic intermediate and less sterically hindered proton transfer.

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The Diels‐Alder reaction as a click reaction strategy is applied to the preparation of well‐defined polycarbonate (PC)‐block copolymers. A well‐defined α‐anthracene‐terminated polycarbonate (PC‐anthracene) is prepared using 9‐anthracene methanol as an initiator in the ring opening polymerization of benzyl 5‐methyl‐2‐oxo‐1,3‐dioxane‐5‐carboxylate in CH2Cl2 at room temperature for 5 h. Next, a well‐defined α‐furan protected maleimide‐terminated‐poly(ethylene glycol) (PEG11‐MI or PEG37‐MI), ‐poly(methyl methacrylate) (PMMA26‐MI), and ‐poly(ε‐caprolactone) (PCL27‐MI) were clicked with the PC‐anthracene at reflux temperature of toluene to yield their corresponding PC‐based block copolymers (PC‐b‐PEG, PC‐b‐PMMA, and PC‐b‐PCL). The homopolymer precursors and their block copolymers were characterized by using the GPC, NMR and UV analysis. © 2013 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013

AB' type monomers containing a thiolactone unit and vinyl ether moiety have been prepared with high yields. Aminolysis of the thiolactone moiety generates the corresponding thiol in situ, and upon UV-irradiation, radical polyaddition occurs in the same medium, yielding linear poly(amide-urethane)s with different side chain residues and (Poly(Ethylene Oxide)) PEO-like backbone. Moreover, these unique polymers feature lower critical solution temperature behavior in water. Systematic modification of the responsive polymers reveals the influence of the variation of the side chains and the backbone structure on the corresponding solubility properties. In selected cases, multiresponsive polymers have been developed, which also respond to pH and metal concentration.