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An electrophilic substitution–carbonylation reaction on phenylpyridine based on the concept of ‘umpolung’ was used to prepare a series of pyridine based carbonyl compounds and bispyridine derivatives. The key intermediate which enhances this reaction is a base aggregate formed by the association of BuLi with lithium 2-dimethylaminoethanolate (LiDMAE) which is stabilized in nonpolar solvents. The presence of polar chelating amides that are used as acyl donors was found to collapse the superbase aggregates liberating nucleophilic ‘free’ BuLi. These nucleophiles lead a classical nucleophilic reaction to introduce butyl tails on the pre-ligand molecules. Pyridine carbonyl compounds produced by these electrophilic substitution–carbonylation reactions, on treatment with 2,6-diisopropylaniline and (DME)NiBr2 in glacial acetic acid at reflux temperature, gave Ni(II) complexes in good yields in a one pot protocol. These complexes are active toward ethylene, producing selective dimerization and trimerization products.

A new series of synthetic polymer bioconjugate hybrid materials consisting of poly(2-hydroxyethyl meth- acrylate)(p(HEMA))as a synthetic polymer block and poly(L-histidine) (p(His)) as a polypeptide block were syn- thesized by combining atom transfer radical polymerization of HEMA with ring opening polymerization of benzyl- N-carboxy-L-histidine anhydride. The resulting biocompat- ible p(HEMA)25-b-p(His)n (n = 15, 25, 35, and 45) hybrid polymers were investigated for their use as pH-sensitive drug delivery system. Highly uniform microspheres were fabricated by using the microfluidics assisted self-assembly of these block polymers and utilized them as carriers for a chemotherapeutic agent doxorubicin and a beta-lactam antibiotic ampicillin for the evaluation of the drug-loading and release behaviors according to pH, demonstrating the release is sensitive to pH. The capability of the new p(HEMA)-b-p(His) hybrid materials to self-assemble in microenvironments and to effectively encapsulate drug molecules serves as suitable carriers for the delivery of drug molecules with varying physiochemical properties.