Synthesis of novel aromatic macrolactones via ring closing metathesis of substituted phenylalkanoic acid allylic esters

Brown, David P.; Hoàn, Dương Quốc

doi:10.1002/jhet.5570450222

Cited by 10 publications

(7 citation statements)

References 29 publications

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“…NMR was used to monitor the progress of the allylation reaction (Figure and Figures S1–S6; data obtained on aSA and a4HBA were discussed in ref ), which are agreement with prior literature. − The 1 H NMR spectra of all allylated phenolic acids show the disappearance of peaks located in the range of 8–14 ppm associated with the carboxyl and hydroxyl groups in the phenolic acids. The peaks located in the region of 4–6 ppm correspond to the allyl groups in the allylated phenolic acids.…”

Section: Resultssupporting

confidence: 82%

Thiol–Ene Elastomers Derived from Biobased Phenolic Acids with Varying Functionality

et al. 2016

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The synthesis and physical properties of thiol− ene elastomers derived from plant-based phenolic acids were explored. Phenolic acids of varying functionality (ranging from 2 to 4 hydroxyl and carboxyl groups per molecule) and relative placement of functional groups (ortho, meta, para) were allylated and subsequently reacted with a multifunctional thiol using a photoinitiator. The thermal and mechanical behaviors of the resulting elastomers were characterized. The networks derived from difunctional allylated phenolic acids exhibited narrow glass transitions (indicating a high degree of network homogeneity) and glass transition temperatures (T g ) which correlated with their cross-link density. The para placement of allyl groups on the allylated phenolic acid produced a network with the highest cross-link density, T g , modulus, tensile strength, and elongation at break (followed by ortho and then meta). As the functionality of the allylated monomer increased (to 3−4 allyl groups per molecule), the cross-link density remained high yet the T g decreased, attributed to a lower concentration of benzene rings throughout the network structure (as all networks were prepared at the stoichiometric ratio of allyl and thiol functional groups). The networks derived from the higher functionality allylated phenolic acids also exhibited lower elongation at break and associated tensile strength and tensile toughness, likely due to increased heterogeneity of the networks (indicated by higher glass transition widths compared to the networks derived from difunctional allylated phenolic acids). All networks exhibited behavior consistent with an ideal elastomer (affine network) at low to moderate strains, albeit with lower moduli than predicted from the monomer chemical structure. At the high end of the strain ranges achieved, some of the networks exhibited strain hardening behavior. This work develops fundamental relationships between the molecular structure of the phenolic acids, including number and placement of functional groups, and the physical properties of the resulting networks.

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Section: Resultssupporting

confidence: 82%

Thiol–Ene Elastomers Derived from Biobased Phenolic Acids with Varying Functionality

et al. 2016

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“…The peaks located at 13.93 and 11.27 ppm indicate the presence of carboxyl and hydroxyl groups in SA before allylation. The 1 H NMR spectrum of allylated SA is shown in Figures a and S1. , No peaks are detected at 13.93 and 11.27 ppm, indicating the disappearance of the hydroxyl and carboxyl groups. The peaks located in the region of 4–6 ppm correspond to the allyl groups in the allylated SA.…”

Section: Resultsmentioning

confidence: 99%

“…The 4-hydroxybenzoic acid (4HBA) was allylated following the same procedures. The 1 H NMR spectra of 4HBA and allylated 4HBA ,, are shown in Figures b and S2. The reaction conversion was 99.6%, and the allylated 4HBA was isolated in a 88% yield.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and Physical Properties of Thiol–Ene Networks Utilizing Plant-Derived Phenolic Acids

et al. 2015

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Elastomeric polymer films synthesized through thiol−ene chemistry, suitable in applications as coatings and adhesives due to their ease of preparation and superior physical properties, are traditionally derived from petroleum sources. Of recent interest is the exploration of sustainable alternatives for the precursors to these materials. Here, we report the synthesis of thiol−ene networks through the photoinitiated reaction between allylated plant-based phenolic acids (salicylic acid and 4hydroxybenzoic acid) and a multifunctional thiol, followed by isothermal annealing. Plant-sourced phenolic acids offer many advantages as biorenewable monomers: their rigid aromatic rings are expected to provide mechanical strength to the resulting polymers and the presence of multiple hydroxyl and carboxyl groups leads to ease of functionalization. Both phenolic acids produced networks with high degrees of homogeneity and few defects, as evidenced by narrow glass transitions and consistency of their tensile behavior with the ideal elastomer model at low-to-moderate strains. The 4-hydroxybenzoic acid based network, which had a higher cross-link density, exhibited a higher glass transition temperature, modulus, tensile strength, and elongation at break as compared to the salicylic acid based network. This work develops fundamental relationships between the molecular structure of the phenolic acids and the physical properties of the resulting networks.

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“…The reaction of anthranilic acid 1a with allylbromide gives the corresponding allyl esters (Scheme 1). 12 ' RESULTS AND DISCUSSION When a mixture of anthranilic acid 1a and allyl alcohol 2a was stirred in the presence of Pd(OAc) 2 (5 mol %) and sodium diphenylphosphinobenzene-3-sulfonate (TPPMS, 10 mol %) in ABSTRACT: Palladium-catalyzed N-allylation of anthranilic acids 1aÀj with allyl alcohol 2a in the presence of Pd(OAc) 2 , sodium diphenylphosphinobenzene-3-sulfonate (TPPMS) in THFÀH 2 O at room temperature gave only mono-N-allylated anthranilic acids 3aÀj in good yields (70À98%). The reactions of 4-bromoanthranilic acid 1i with 2-methyl-3-buten-2-ol 2b showed complete chemoselectivity in N-allylation (neutral conditions) and C-vinylation (basic conditions).…”

Section: ' Introductionmentioning

confidence: 99%

“…In contrast, there are few examples of direct N -allylation of anthranilic acids. The reaction of anthranilic acid 1a with allylbromide gives the corresponding allyl esters (Scheme ) …”

Section: Introductionmentioning

confidence: 99%

Palladium-Catalyzed Mono-N-allylation of Unprotected Anthranilic Acids with Allylic Alcohols in Aqueous Media

Hikawa

Yokoyama

2011

J. Org. Chem.

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Palladium-catalyzed N-allylation of anthranilic acids 1a-j with allyl alcohol 2a in the presence of Pd(OAc)(2), sodium diphenylphosphinobenzene-3-sulfonate (TPPMS) in THF-H(2)O at room temperature gave only mono-N-allylated anthranilic acids 3a-j in good yields (70-98%). The reactions of 4-bromoanthranilic acid 1i with 2-methyl-3-buten-2-ol 2b showed complete chemoselectivity in N-allylation (neutral conditions) and C-vinylation (basic conditions). In our catalytic system, the keys to success are use of an unprotected anthranilic acid as a starting material and the presence of water in the reaction medium. The carboxyl group of anthranilic acid and water may play important roles for the smooth generation of the π-allyl palladium species by activation of the hydroxyl group of the allylic alcohol.

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Synthesis of novel aromatic macrolactones via ring closing metathesis of substituted phenylalkanoic acid allylic esters

Abstract: Stable aromatic macrolactones have been synthesized and characterized from 2‐ and 3‐substituted phenylalkanoic acid systems in modest yields.

Cited by 10 publications

References 29 publications

Thiol–Ene Elastomers Derived from Biobased Phenolic Acids with Varying Functionality

Thiol–Ene Elastomers Derived from Biobased Phenolic Acids with Varying Functionality

Synthesis and Physical Properties of Thiol–Ene Networks Utilizing Plant-Derived Phenolic Acids

Palladium-Catalyzed Mono-N-allylation of Unprotected Anthranilic Acids with Allylic Alcohols in Aqueous Media

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