Spotting Trends in Organocatalyzed and Other Organomediated (De)polymerizations and Polymer Functionalizations

Abstract

Organocatalysis has evolved into an effective complement to metal‐ or enzyme‐based catalysis in polymerization, polymer functionalization, and depolymerization. The ease of removal and greater sustainability of organocatalysts relative to transition‐metal‐based ones has spurred development in specialty applications, e.g., medical devices, drug delivery, optoelectronics. Despite this, the use of organocatalysis and other organomediated reactions in polymer chemistry is still rapidly developing, and we envisage their rapidly growing application in nascent areas such as controlled radical polymerization, additive manufacturing, and chemical recycling in the coming years. In this Review, we describe ten trending areas where we anticipate paradigm shifts resulting from novel organocatalysts and other transition‐metal‐free conditions. We highlight opportunities and challenges and detail how new discoveries could lead to previously inaccessible functional materials and a potentially circular plastics economy.

Naphthalene engineering of chemically recyclable polyesters with enhanced thermal and mechanical properties

“…Organo-mediated polymerization has attracted growing attention because of the mild reaction conditions and being free of metal contaminants. [55][56][57] Organic bases TBD, DBU, and t-BuP 4 were investigated as the catalysts for ROP of M1 under similar reaction conditions (Scheme 1). DBU and t-BuP 4 demonstrated modest to poor catalytic activity for the ROP of M1 with a monomer/catalyst/initiator ([M]/[Cat]/[I]) ratio of 200/1/1 (Table 1, entries 1 and 2).…”

Advancements in catalysis for plastic resource utilization

“…Organocatalysis has emerged as an effective method for decomposing waste plastics, serving as a valuable complement to transition metal-based and biocatalysis. 100 Given that plastics are inherently organic polymers, organic reagents offer distinct advantages for recycling waste plastics based on the principle of similar solubility. Organocatalytic degradation can be categorized into alcoholysis, phosphate ester, and alcohol–amine reactions, depending on the specific reagents employed.…”

Structural Effect of Organic Catalytic Pairs Based on Chiral Amino(thio)ureas and Phosphazene Bases for the Isoselective Ring-Opening Polymerization of Racemic Lactide

“…23−29 Recent years have witnessed new achievements at the crossroads between organocatalysis and macromolecular science, for instance, through the use of organic catalysts for photopolymerization or for controlled radical polymerization, for chemical recycling and upcycling of synthetic polymers, or for designing covalent adaptative networks. 30 The quest for stereocontrol in polymerization is very much inspired by optically active naturally occurring polymers, such as proteins, deoxyribonucleic acids, or polysaccharides, which exhibit an incomparable level of structural control and possess unique functions. 31−33 A still thriving research area in polymer chemistry is thus the development of stereoselective polymerization methods that can be general to monomer structures.…”

“…, stereoselective polymerization employing chiral organic catalysts, is more recent and remains underexplored. − In a more general way, organic catalysts, whether they are chiral or not, that can provide high stereoselectivity and high catalytic activity, in addition to operating under mild conditions, e.g., at room temperature or above, are rare. − Yet, the use of small organic molecules for organic catalysis of polymerization is now part of the methodological toolbox in macromolecular synthesis. − Depending on the structure of the organic catalyst, different mechanisms can operate, and this diversity of mechanistic pathways allows for improved polymerization rates, tuning of the selectivity, and rational design of a variety of polymer architectures. Organic catalysis of polymerization can offer other advantages over metal-catalyzed reactions, such as a reduced toxicity and cost, easier catalyst synthesis and storage, tolerance to functional groups, and operation at elevated temperatures and in a variety of solvents. − Recent years have witnessed new achievements at the crossroads between organocatalysis and macromolecular science, for instance, through the use of organic catalysts for photopolymerization or for controlled radical polymerization, for chemical recycling and upcycling of synthetic polymers, or for designing covalent adaptative networks …”