Activators regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) conditions utilizing a low concentration of catalyst are successfully applied for the preparation of well-defined poly(glycidyl methacrylate) without the addition of external reducing agents. The living character of polymerization is evidenced by successful chain extensions with methyl methacrylate and methyl acrylate, again, in the absence of additional reducing agents, yielding block copolymers. The epoxide groups in glycidyl methacrylate or the corresponding polymer can serve as an intrinsic reducing agent to continuously regenerate the Cu(I) -based ATRP activator from the Cu(II) halide complex present in the systems. The reactivity of various epoxides in the reduction of the Cu(II) Br2 complex of tris(2-pyridylmethyl)amine is compared.

A new strategy to assign diastereotopic protons was developed on the basis of residual dipolar couplings (RDCs) collected in compressed poly(methyl methacrylate) (PMMA) gels. A combination of 2D J-scaled BIRD HSQC and J-scaled BIRD HMQC/HSQC NMR experiments was used to collect the RDC data. In the proposed strategy, the first experiment is used to measure (1)D(CH) for methine groups, the sum of (1)D(CHa) + (1)D(CHb) for methylene groups and the average (1)D(CH3) value for methyl groups. In turn, the small molecule alignment tensor is calculated using these D values without the a priori assignment of CH(2) diastereotopic protons. The D values of each individual CH bond (CHa and CHb) of each methylene group in the molecule are then predicted using the calculated alignment tensor and these values compared with the results from the HMQC/HSQC experiment, leading to their unambiguous assignment. This strategy is demonstrated with the alkaloid strychnine that contains five methylene groups with diastereotopic protons, and our results fully agree with the previously reported assignment using combinations of permutated assignments.

Star polymers were synthesized by atom transfer radical polymerization (ATRP) using a "core first" approach. Multibrominated, highly branched functional polymers were first synthesized by copolymerizing an epoxide-containing monomer, glycidyl methacrylate (GMA), with divinyl crosslinkers, ethylene glycol dimethacrylate or the reductively degradable bis(2-methacryloyloxyethyl) disulfide, in the presence of an efficient chain transfer agent, CBr 4 . Multiple alkyl bromide chain end groups were present in the branched polymers, which were successfully used as multifunctional macroinitiators, from which both polyacrylateand polymethacrylate-type arms were grown under low catalyst concentration ATRP conditions. Due to the ability of epoxides to reduce Cu II to Cu I complexes, the low catalyst-concentration ATRP chain extensions were performed in the absence of any externally added reducing agents. The cores of the obtained stars, contained numerous epoxide functionalities, originating from GMA, and were efficiently modified using reactions with a variety of tertiary aliphatic amines to afford star polymers with hydrophilic, cationic cores. Ring-opening of the oxirane rings in polyGMA with a pyridine derivative, nicotinamide, in

A two-session experiment is designed to introduce undergraduate students to concepts in catalysis, transition metal complexes, polymer synthesis, and postpolymerization modifications. In the first session, students synthesize poly(glycidyl methacrylate) via low-catalystconcentration atom transfer radical polymerization (ATRP). The lowcatalyst-concentration technique simplifies the experimental setup, reduces the cost of the synthesis, eliminates the need for catalyst removal from the product, and thus ultimately makes ATRP an environmentally benign process. In the second session, students modify the well-defined epoxidecontaining polymers with nicotinamide in the presence of acetone, to afford fluorescent polymers.

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