Single-Electron Transfer and Single-Electron Transfer Degenerative Chain Transfer Living Radical Polymerization

Abstract

Introduction 5069 1.1. Living Radical Polymerization (LRP). Definitions and Brief History 5070 1.2. Scope of the Review 5071 2. Path to SET-LRP and SET-DTLRP: Sulfonyl Halides as "Universal" Initiators for Cu-Catalyzed LRP 5071 2.1. Cuprous Halide Catalysts for LRP Initiated with Sulfonyl Halides 5071 2.2. Cu 0 and Cu 2 O Catalysts for LRP Initiated with Sulfonyl Chlorides 5072 2.3. Arenesulfonyl Bromides, Arenesulfonyl Iodides, and N-Centered Initiators 5073 2.4. TERMINI. The First Iterative Method Based on LRP 5074 3. SET-DTLRP 5075 3.1. Toward the LRP of Vinyl Chloride (VC) 5075 3.1.1. Cu 0 Overcomes the Challenge of Reactivation Required for the Living Radical Polymerization of VC 5075 3.1.2. Cu 0 Catalyzed SET-DTLRP of VC via the Disproportionation of Cu I 5076 3.1.

Recent developments in metal-catalyzed living radical polymerization

“…17,61,62 More recently, Percec and co-workers proposed that the Cu(0)-based living radical polymerization proceeds via a single-electron transfer mechanism under certain conditions and that their systems are highly effective for the very fast living radical polymerization of various monomers, leading to well-controlled high-molecular weight polymers with narrow MWDs. [63][64][65][66] In contrast, the Cu(I)-based systems in the presence of reducing agents, such as tin(II) 2-ethylhexanoate, ascorbic acid, Cu(0) and radical initiators, also induced an efficient living radical polymerization, in which the accumulated Cu(II) species changed into the active Cu(I) species via the reduction by these additives.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] Besides these metal catalytic systems, there have also been substantial developments in various living radical polymerizations, such as nitroxide-mediated polymerizations, reversible addition fragmentation chain-transfer polymerizations and others, and in all of these, there are characteristic features of the mechanisms and components. [18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34] The metal-catalyzed living radical polymerization was originally discovered via evolution of the metal-catalyzed Kharasch or atom transfer radical addition reaction 35 to the chain-growth polymerization of vinyl monomers ( Figure 1).…”

“…The details on how we discovered the catalytic systems can be found in our previous reviews. 7,9 In contrast, the most extensively used catalysts are based on copper with nitrogen ligands, which were separately developed by many research groups, including Matyjaszewski, Percec, Haddleton and others [2][3][4][12][13][14][15][16][17] (The reaction mechanisms for the metal-catalyzed living radical polymerization and ATRP are supposed to be the same. Although the former name is mostly used in this review, it never intends to exclude the latter.…”

“…Thus, a wide variety of conjugated monomers, such as methacrylates, acrylates, styrenes (Sts), acrylamides and acrylonitrile, can now be polymerized in a controlled fashion, although a truly well-controlled radical polymerization of unconjugated monomers such as vinyl acetate (VAc) is still one of the most challenging topics in metal-catalyzed living radical polymerizations. [6][7][8][9][10][11][12][13][14][15][16][17] In addition, the amounts of the metal catalyst used in the polymerizations have decreased owing to the evolution of the active catalysts or the addition of reducing agents for the oxidized metal catalysts. However, these are still challenges for industrial applications.…”

“…[6][7][8][9][10][11][12][13][14][15][16][17] They include not only well-known controlled polymer structures such as end-functionalized, block, graft and star polymers, but also other more complicated or unique structures, which have been extremely difficult to synthesize, such as gradient polymers, ring polymers and multiple controlled structures. In particular, for the precision synthesis of these highly ordered structures, metal-catalyzed systems are the most preferable methods in comparison to other living radical polymerization systems for the following reasons.…”