Synthesis Methodology of End-Functionalized Poly(quinolylene-2,3-methylene)s: Living Cyclocopolymerization Using Aryl Palladium Initiators Conveniently Prepared from Versatile Aryl Halide

Abstract

The facile synthesis of end-functionalized poly-(quinolylene-2,3-methylene)s using aryl palladium initiators conveniently prepared from versatile aryl halides has been reported. When various aryl palladium complexes with 1,3bis(diphenylphosphino)propane, synthesized by the oxidative addition of an aryl halide to Pd(PPh 3 ) 4 and the ligand exchange reaction, were used as initiators, cyclocopolymerization of o-allenyl aryl isocyanide afforded poly(quinolylene-2,3-methylene)s with a narrow molecular weight distribution (M w /M n = 1.06−1.12), and each aryl group on the palladium complex was quantitatively introduced into the α-chain end. The end-functionalization system was successfully applied to a one-pot polymerization, which did not require the isolation of each aryl palladium complex. This method can be used for many aryl halides, including commercially available products, and has successfully obtained end-functionalized polymers with a wide variety of end functional groups, including bulky and reactive substituents. Furthermore, we expanded this system to synthesize block copolymers with polylactide and multiarmed polymers using initiators with multiple starting points.

Synthesis of helically π-stacked poly(quinolylene-2,3-methylene)s with anthracene derivatives at the chain end: intramolecular energy transfer based on the π-stacked architecture

“…Following a previously reported procedure, 41 cyclocopolymerization of 1a–c using anthracenyl palladium complexes [ Pd-Anth(a–d) ] as initiators ([ 1 ]/[ Pd-Anth ] = 20) was conducted at 25 °C (Scheme 2, and entries 2–7 in Table 1). Furthermore, the cyclocopolymerizations of 1a using Pd-Anth(a) at different initial feed ratios ([ 1a ]/[ Pd-Anth(a) ] = 10, 30, 50) were also conducted (entries 8–10 in Table 1).…”

“…Because the present design of π-stacked PQMs allows easy modification of the α-chain end, the construction of an efficient system in which energy transfer occurs can be expected by tuning the structure based on PQM. Additionally, because the palladium complex remains at the ω-chain end of the presented polymers after polymerization, 41 the quantitative replacement of the complex with a functional group is expected to lead to the development of telechelic polymers with arbitrary structures, such as donor and acceptor moieties at each end of π-stacked PQMs. Studies on the design of new functional polymers based on π-stacked PQMs are also in progress.…”

“…Recently, we extended the living cyclocopolymerization process to include the facile synthesis of end-functionalized PQMs using aryl-palladium complexes. 41 The resulting polymer could quantitatively introduce an arbitrary aryl group into the initiating chain end (α-chain-end) of the polymers. Therefore, studies on the design of new functional polymers based on end-functionalized PQMs are expected.…”

Facile End‐Functionalization of Poly(Quinolylene‐2,3‐Methylene) Using the Terminal Palladium Complex: Thiocarbonylation through Formation of an Acyl Palladium Complex at the Polymer Terminal

“…Despite the presence of the protic NH proton, 2i and 2j could be introduced (entries 9 and 10). Additionally, aryl-methanethiol (2k-2m) and aryl mercaptan (2n and 2o) could also be applied to the reaction (entries [11][12][13][14][15]. Previously, a novel 𝜋-stacked helical PQM was synthesized using monomer 1b baring an L-norleucine derivative.…”

“…Recently, a facile synthesis of end‐functionalized poly‐1 at initiating terminal ( α ‐chain‐end) using aryl palladium initiators was reported. [ 12 ] Furthermore, we developed an end‐functionalized methodology to synthesize a π ‐stacked PQM with anthracene derivatives as energy acceptors at the α ‐chain, resulting in polymers that exhibited energy transfer properties. [ 13 ] Thus, it is possible to develop functional polymers based on PQM by controlling the terminal structure.…”