No abstract

The organocatalytic ring-opening polymerization (OROP) of cyclic carbonate monomers derivatized with metallocenes is described for the rapid synthesis of high Mn metallopolymers where the metal is pendant to the polymer...

Biodegradable polymers are desirable to mitigate the environmental impact of plastic waste in the environment. Over the past several decades, the development of organocatalytic ring-opening polymerization (OROP) has made the synthesis of many new types of biodegradable polymers possible. In this research article, the first example of an oxygen atom transfer reagent pendant on a biodegradable polymer backbone is reported. The monomers for the polycarbonate backbone are sourced from the biodegradable 2,2-bis(hydroxymethyl) propionic acid molecule, and an iodoaryl group is installed pendant to the cyclic monomer for post-polymerization modification into an iodosylaryl oxygen atom transfer reagent. The key I-O bond is characterized by XPS spectroscopy, and a test reaction to triphenylphosphine demonstrates the ability of the polymer to engage in an oxygen atom transfer reaction with a substrate.

The oxidation of an acetonitrile ligand coordinated to ruthenium is explored in deuterated dimethylsulfoxide by 1 H NMR spectroscopy. When oxidized with an iodosoarene oxygen atom transfer (OAT) reagent, kinetic studies demonstrate that the nitrile ligand does not dissociate before reacting. Instead, OAT to the central nitrile carbon is implicated (nitrile oxidation), and is further supported by the product of the reaction, N-acyl-dimethylsulfoximine. The N-acyldimethylsulfoximine likely formed by an imido group transfer reaction from ruthenium to the NMR solvent, and the product was synthesized independently to verify its identity in the reaction. This reaction represents the first time that a nitrile oxidation reaction has resulted in intermolecular imido group transfer to a substrate, presumably through a reactive ruthenium(IV)imido intermediate. This suggests that nitrile oxidation is a plausible route into reactive metal-imido intermediates for amination and aziridination reactions.