Oxadiazabicyclooctenone as a versatile monomer for the construction of pH sensitive functional polymers via ROMP

Abstract

Herein, oxadiazabicyclooctenone is successfully developed as a versatile monomer for the construction of new pH-sensitive polymers by ROMP.

Modular Approach to Degradable Acetal Polymers Using Cascade Enyne Metathesis Polymerization

“…[8][9][10] Ac ellulose-derived levoglucosenol monomer recently described by Schlaad and co-workers produced high molecular weight polyacetal thermoplastics,t hough without control of molecular weight and dispersity. [12][13][14] While the dispersities reported were modest, targetable molecular weights were obtained in good agreement with theory.F urther,t he examples by Schlaad and Kiessling required significantly acidic (pH < 4) or basic conditions (pH > 9) to degrade,l eading to materials that would persist in abiological environment for long periods of time. [12][13][14] While the dispersities reported were modest, targetable molecular weights were obtained in good agreement with theory.F urther,t he examples by Schlaad and Kiessling required significantly acidic (pH < 4) or basic conditions (pH > 9) to degrade,l eading to materials that would persist in abiological environment for long periods of time.…”

“…[11] The most successful strained monomer to date is Kiesslings bicyclico xazinone system, which features an easily modified synthetic handle for introducing fluorophores and bioactive epitopes ( Figure 1B). [12][13][14] While the dispersities reported were modest, targetable molecular weights were obtained in good agreement with theory.F urther,t he examples by Schlaad and Kiessling required significantly acidic (pH < 4) or basic conditions (pH > 9) to degrade,l eading to materials that would persist in abiological environment for long periods of time.…”

“…A cellulose‐derived levoglucosenol monomer recently described by Schlaad and co‐workers produced high molecular weight polyacetal thermoplastics, though without control of molecular weight and dispersity . The most successful strained monomer to date is Kiessling's bicyclic oxazinone system, which features an easily modified synthetic handle for introducing fluorophores and bioactive epitopes (Figure B) . While the dispersities reported were modest, targetable molecular weights were obtained in good agreement with theory.…”

Tailored silyl ether monomers enable backbone-degradable polynorbornene-based linear, bottlebrush and star copolymers through ROMP

“…Multiple examples of degradable ROMP polymers prepared via the use of non-norbornene-based monomers have been reported. [18][19][20][21] Though elegant, these monomers sometimes require lengthy syntheses; they display limited copolymerization efficiency with norbornene derivatives; or the polymers they produce are degradable only under forcing conditions. In addition, one example of a copolymer of norbornene and an oxadiazinone was reported to display sluggish hydrolysis under aqueous conditions, even at pH 1.…”

“…In addition, one example of a copolymer of norbornene and an oxadiazinone was reported to display sluggish hydrolysis under aqueous conditions, even at pH 1. 20 A straightforward approach to welldefined backbone-degradable co-polymers of norbornene-based (macro)monomers would significantly expand the functional scope of materials prepared by ROMP and, combined with the advent of catalytic ROMP, could make ROMP the go-to choice for the synthesis of advanced materials. 22 Here, a class of bifunctional silyl-ether-based cyclic olefins that offers a general solution to this problem is described (Figure 1b).…”