Cyclopolymerization of o‐phthalaldehyde

ABSTRACT:Polymerization of o-formylpheny1acetaldehyde was carried out with various catalysts. The polymer obtained below -60°C with BFsOEt2 catalyst was soluble in common organic solvents and was confirmed as a cyclopolymer composed of 6-membered cyclized units. The cationic cyclization step in the cyclopolymerization of o-formylphenylacetaldehyde was inferred to proceed through a intermediate or concerted scheme similar to those proposed for the cationic propagation of o-phthalaldehyde.On the other hand, under cationic polymerization conditions over -40°C o-formylphenylacetaldehyde gave a cyclic trimer (mp 284-285°C) possessing fused ring ether, which had no aldehyde group. Interestingly, the cyclic trimer was also produced from the polymer by treatment with BFsOEt2 in methylene dichloride.Cyclopolymers of o-formylphenylacetaldehyde were also obtained with Ziegler catalyst at 0 and -78°C, and with t-BuOLi catalyst at -78°C.

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“…2, No. 1,1971 in eq 6. The other is the formation of the trimer by back-biting of the propagating chain, as illustrated in eq 7.…”

Section: Discussionmentioning

confidence: 99%

“…2, No. 1,1971 trimer was obtained by connecting a spectro accumulator. An X-ray powder spectrum was taken with a Norelco (North American Phillips Co.).…”

Section: Equipmentmentioning

confidence: 99%

Polymerization of Aromatic Aldehydes. VII. Cyclopolymerization of o-FormylphenylacetaIdehyde and Formation of a Cyclic Trimer

Tagami

Kagiyama

Aso

1971

Polym J

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“…PPA was first reported in 1967 by Aso and Tagami, who observed the cationic polymerization of o ‐PA at low temperature (−78 °C), catalyzed by BF 3 ·OEt 2 . In 1969, several other cationic catalysts such as SnCl 4 , TiCl 4 and (C 6 H 5 ) 3 C + BF4 − were also reported to successfully polymerize o ‐PA .…”

Section: Polymerizationmentioning

confidence: 94%

“…Yet, these polymerization techniques offer interesting results and prospectives on the stereoselective polymerization. γ‐Ray irradiation from a 60 Co source was used in the polymerization of o ‐PA in CH 2 Cl 2 at −78 °C . The work‐up procedure was similar to the one used in cationic polymerization, yielding white powdery PPA with cis content of about 87%.…”

Section: Polymerizationmentioning

confidence: 99%

“…Still, simple aromatic aldehydes (such as benzaldehyde) could not be polymerized. In 1967, Aso demonstrated the first polymerization of an aromatic aldehyde, o ‐phthalaldehyde ( o ‐PA), which is cheaply produced by the ozonolysis of naphthalene. Contrary to other aromatic aldehydes, o ‐PA could be polymerized under the conditions developed for higher aliphatic aldehydes, probably due to the intramolecular cyclopolymerization.…”

Section: Introductionmentioning

confidence: 99%

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Polyphthalaldehyde: Synthesis, Derivatives, and Applications

Wang

Diesendruck

2017

Macromol. Rapid Commun.

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o-Phthalaldehyde is, to this day, the only aromatic aldehyde that can be homopolymerized through chain-growth polymerization. The product, polyphthalaldehyde (PPA), is a brittle white solid, and, having a polyacetal main chain, presents the ability to depolymerize quite rapidly in the presence of an acid. This review highlights the unique polymerization chemistry of o-phthalaldehyde since its discovery over half a century ago, describing the different methods for the preparation of PPA and its derivatives, how the polymerization chemistry affects the structure and thermomechanical properties of the obtained PPA, and summarizes recent developments in PPA chemistry as a responsive material. Modern material applications such as the use of PPA as photoresists or in thermal-scanning probe lithography, as well as exploration of judiciously end-capped PPA for its use as self-immolative materials are summarized. In addition, the use of PPA blocks in copolymers is described, leading to the development of films with well-defined nanochannels or nanopores that can serve as a template for the preparation of the microorganization of nanomaterials.

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Metathesis Cascade‐Triggered Depolymerization of Enyne Self‐Immolative Polymers**

2021

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A novel class of enyne self-immolative polymers (SIPs) capable of metathesis cascade-triggered depolymerization is reported. Studies on model compounds established 1,6enyne structures for efficient metathesis cascade reactions. SIPs incorporating the optimized 1,6-enyne motif were prepared via both polycondensation and iterative exponential growth approaches. These SIPs demonstrated excellent stability in strong acid, base, nucleophiles, or at elevated temperatures, and can undergo efficient and complete depolymerization once triggered by a metathesis catalyst. Further studies revealed that introducing a terminal alkene to the chain end of the enyne SIPs improved the depolymerization efficiency, and established their potential as stimuli-responsive materials. Scheme 1. Development of the enyne self-immolative polymer. Scheme 2. Enyne metathesis of model compounds.

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Cyclopolymerization of o‐phthalaldehyde

Cited by 27 publications

References 9 publications

Polymerization of Aromatic Aldehydes. VII. Cyclopolymerization of o-FormylphenylacetaIdehyde and Formation of a Cyclic Trimer

Polymerization of Aromatic Aldehydes. VII. Cyclopolymerization of o-FormylphenylacetaIdehyde and Formation of a Cyclic Trimer

Polyphthalaldehyde: Synthesis, Derivatives, and Applications

Metathesis Cascade‐Triggered Depolymerization of Enyne Self‐Immolative Polymers**

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