Versatile Routes to Functional RAFT chain transfer agents

Graphical abstract

The paper ‘Versatile Routes to Functional RAFT Chain Transfer Agents through the Passerini Multicomponent Reaction’ has just been published in ACS Macro Letters and is now available online.

The RAFT methodology is one of the most commonly used living radical polymerization techniques, partly due to the ease and utility of installing a functional chain transfer agent onto the ends of the generated polymer chains. The Passerini multicomponent reaction offers great versatility in converting a wide range of easily accessible building blocks to functional materials. This work, combines the two approaches such that a single, commonly available, RAFT agent is used in Passerini reactions to generate a variety of multifunctional RAFT chain transfer agents containing ester linkages. The Passerini-RAFT agents could exert control over radical polymerization generating materials of well-defined molecular weights and dispersity. The presence in these polymer cores of ester and amide functionality through the Passerini chemistries, provided regions in the materials which are inherently biodegradable, facilitating any subsequent biomedical applications. The work overall demonstrates a versatile and facile synthetic route to multi-functional RAFT chain transfer agents and biodegradable polymers.

The Passerini reaction was employed as a facile method for the functionalization of RAFT chain transfer agents. This doesn’t require the synthesis of new individual RAFT agents and allows for the modification of a single CTA to include new functionalities. The Passerini reaction has a wide functional group tolerance, so it’s possible to modify the RAFT agents to include a very wide range and combination of functional groups. Additionally, the modified CTAs were able to control the RAFT polymerization of both a hydrophilic and hydrophobic monomer, as well as demonstrating applicability for the synthesis of amphiphilic or branched polymers.