RAFT Polymerization and Thiol Chemistry: A Complementary Pairing for Implementing Modern Macromolecular Design

Abstract

Reversible addition fragmentation chain transfer (RAFT) polymerization is one of the most extensively studied reversible deactivation radical polymerization methods for the production of well-defined polymers. After polymerization, the RAFT agent end-group can easily be converted into a thiol, opening manifold opportunities for thiol modification reactions. This review is focused both on the introduction of functional end-groups using well-established methods, such as thiol-ene chemistry, as well as on creating bio-cleavable disulfide linkages via disulfide exchange reactions. We demonstrate that thiol modification is a highly attractive and efficient chemistry for modifying RAFT polymers.

Living Radical Polymerization by the RAFT Process – A Third Update

“…These include the thiolene reaction and other processes as shown in Scheme 11. [34,35] Thiol-click reactions have been reviewed [71] and references to some recent examples of these process are included in Table 18.…”

“…include those on the kinetics and mechanism of RAFT polymerization, [26,27] RAFT agent design and synthesis, [28] the use of RAFT to probe the kinetics of radical polymerization, [29] microwaveassisted RAFT polymerization, [30,31] RAFT polymerization in microemulsion, [32] end-group removal/transformation, [33][34][35][36] the use of RAFT in organic synthesis, [37] the combined use of RAFT polymerization and click chemistry, [38] the synthesis of star polymers and other complex architectures, [39][40][41][42] the synergistic use of RAFT polymerization and ATRP, [43,44] the synthesis of self assembling and/or stimuli-responsive polymers, [45][46][47] and the use of RAFT-synthesized polymers in green chemistry, [48] polymer nanocomposites, [49][50][51] drug delivery and bioapplications, [41,46,47,[52][53][54][55][56][57][58][59][60] and applications in cosmetics [61] and optoelectronics. [62] The process is also given substantial coverage in most recent reviews that, in part, relate to polymer synthesis, living or controlled polymerization or novel architectures.…”

pH-Degradable Mannosylated Nanogels for Dendritic Cell Targeting

“…Indeed, Z-end group transformation with divinyl sulfone or methane thiosulfonate has been shown an attractive approach to introduce cysteine-reactive moieties for further bio-conjugation. 41,[54][55][56] Alternatively, the Z-end group can, upon aminolysis, easily be capped by acrylates and acrylamides via Michael addition. 57,58 In the present work we use this route to cap the thiol end-groups by addition of an excess of N-hydroxyethyl acrylamide, introducing a hydroxyl group at the polymer chain ends.…”

Postpolymerization synthesis of (bis)amide (co)polymers: Thermoresponsive behavior and self-association

“…Aminolysis of activated PFP ester side groups can be expected to cleave the trithiocarbonate end groups, and is, in fact, the most common way for effecting RAFT end group modification. [33,34] In order to prevent side reactions of the resulting thiol end groups, acrylamide was added as a thiol scavenger (Michael acceptor), which, featuring an amide moiety, produces end groups with high chemical similarity to the (bis)amide repeating groups, thus eliminating possible end groups effects on aqueous solution behavior (see Scheme 1).…”