Polymer up-cycling by mangana-electrocatalytic C(sp³)–H azidation without directing groups

Abstract

The chemical up-cycling of polymers into value-added materials offers a unique opportunity to place plastic waste in a new value chain towards a circular economy. Herein, we report the selective...

When transition-metal catalysis meets electrosynthesis: a recent update

“…Along this line, Ackermann and co-workers developed a mangana-electrocatalyzed C(sp 3 )–H azidation of polymers in the absence of chemical oxidants (Scheme 5). 38 This electrochemical protocol features a wide substrate scope. In addition to polyethylenes, a variety of polypropylenes and polystyrenes are also electrochemically azidated without significant polymer chain degradation.…”

Electrochemical recycling of polymeric materials

“… 96 By applying a low, oscillating cell potential of ±1 V vs. SHE on a Cu electrode, suspended LDPE in an acidic electrolyte containing CuSO 4 was partially electrochemically oxidized, as observed by a significant increase of C O, C–O and C C signals in the post-catalysis IR spectrum of the resulting polymer. 97 However, the approach also led to C sp 3 –C sp 3 bond scission and the formation of smaller molecules such as dodecanoic acid. 96 In another study, Ackermann et al reported the electrochemical azidation of C sp 3 –H bonds in polystyrene ( Fig.…”

Selective Electrocatalytic Degradation of Ether‐Containing Polymers

“…More recently, Román‐Leshkov and co‐workers explored the efficacy of electrochemically formed phthalimido‐ N ‐oxyl (PINO) radicals to activate benzylic C−H bonds in small molecules—reporting a combination of oxidation and C−C bond scission events, with promising initial results applying this strategy toward polystyrene degradation [55] . Earlier this year, Luca and co‐workers reported an electroreductive degradation of poly(ethylene terephthalate), [56] and Ackermann and co‐workers developed a mangana‐electrocatalytic azidation of polystyrene, polyethylene, and polypropylene with up to 7 mol % functionalization [57] . Among these early examples of electrochemical polymer degradation and upcycling, other inspiring work includes that by Stephenson, Stahl, and others to depolymerize lignin using oxidative C−H activation strategies [58–61] …”

“…[55] Earlier this year, Luca and co-workers reported an electroreductive degradation of poly(ethylene terephthalate), [56] and Ackermann and co-workers developed a mangana-electrocatalytic azidation of polystyrene, polyethylene, and polypropylene with up to 7 mol % functionalization. [57] Among these early examples of electrochemical polymer degradation and upcycling, other inspiring work includes that by Stephenson, Stahl, and others to depolymerize lignin using oxidative CÀ H activation strategies. [58][59][60][61] Our group recently reported a strong, biorenewable thermoplastic-poly(2,3-dihydrofuran) (PDHF)-which was synthesized via cationic polymerization of a cyclic vinyl ether.…”