Protected Vinyl Catechol from Caffeic Acid and ... - ACS Publications

Letter Cite This: ACS Sustainable Chem. Eng. XXXX, XXX, XXX−XXX

pubs.acs.org/journal/ascecg

Scalable Synthesis of Bio-Based Functional Styrene: Protected Vinyl Catechol from Caffeic Acid and Controlled Radical and Anionic Polymerizations Thereof Hisaaki Takeshima, Kotaro Satoh,* and Masami Kamigaito* Department of Molecular and Macromolecular Chemistry, Graduate School of Engineering, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603, Japan

Downloaded via UNIV OF SOUTH DAKOTA on October 25, 2018 at 04:13:34 (UTC). See https://pubs.acs.org/sharingguidelines for options on how to legitimately share published articles.

S Supporting Information *

ABSTRACT: Naturally abundant caffeic acid, a cinnamic acid derivative with a catechol group in its structure, was quantitatively converted into a series of protected vinyl catechol (VC) derivatives via facile and scalable decarboxylation and protection reactions. Controlled radical polymerizations of the protected VCs proceeded well using the appropriate reversible addition−fragmentation chain transfer agent or alkoxyamine to generate well-defined polymers, although the reaction rates and molecular weight distributions of the obtained polymers were dependent on the protecting groups on the monomers. Anionic polymerizations of the VCs were also achieved with the appropriate protecting groups (−SiMe2tBu or −SiiPr3) using secbutyllithium as an initiator in THF at −78 °C. Furthermore, the tacticities of the obtained polymers could be controlled by varying the conditions of the polymerizations and the protecting groups on the monomers in the anionic polymerization. KEYWORDS: Renewable resources, Phenylpropanoid, Bioaromatics, Caffeic acid, Catechol, Decarboxylation, Radical polymerization, Anionic polymerization

■

polymerized via radical and anionic polymerizations.30−40 We have also reported the synthesis of a vinyl catechol protected with two triethylsilyl groups (TES2VC) from 4-vinylguaiacol, which was derived from naturally occurring ferulic acid by decarboxylation followed by dealkylation with triethylsilane with a catalytic amount of B(C6F5)3.41 The resulting protected VC could be successfully polymerized using a reversible addition−fragmentation chain transfer (RAFT) radical polymerization and deprotected to afford well-defined poly(vinyl catechol). 3,4-Dihydroxycinnamic acid (caffeic acid) is an abundant catechol-containing natural aromatic compound that can be found in many plant cells as a key intermediate in the biosynthesis of lignin as phenylpropanoid,42,43 and its ester form is common in coffee beans and grounds.44 Although numerous attempts have been made to prepare polymeric materials from caffeic acid, most of them were limited to condensation polymerizations due to loss of the original phenolic groups in the catechol moiety.45,46 As in our previous paper,41 the decarboxylation of such cinnamic acid analogues is one of the most promising procedure to obtain functional

INTRODUCTION The polymerization of monomers bearing pendent functional groups is a highly effective and facile way to create novel, advanced, high-performance polymer materials. In the case of styrene, the derivatives that have actually been produced industrially are rather limited to chloromethylstyrene, protected vinylphenol, bromostyrene, etc., but these species have been polymerized via various reaction intermediates, including radical, anionic, cationic, and metal-coordinating species. Among these derivatives, polystyrenes with phenolic groups have been used for a wide range of applications, such as resist,1 adhesive, and epoxy-curing materials; however, the phenolic group in the monomer typically needs to be protected during polymerization.2,3 The use of renewable natural products is currently attractive from the viewpoint of sustainable developments both in science and industry.4−20 Some natural compounds contain phenolic catechol groups exhibiting important functions in nature, such as antisunburn, reductant, and curing functionalities.21,22 For example, mussel adhesive protein contains catechol groups, which work on the surfaces of various substrates even in water.23−25 Therefore, vinyl monomers with catechol groups, including vinyl catechol (VC), have recently been intensely studied to mimic natural functions.26−40 A variety of protected VC monomers have been prepared and © XXXX American Chemical Society

Received: September 1, 2018 Revised: October 12, 2018

A

DOI: 10.1021/acssuschemeng.8b04400 ACS Sustainable Chem. Eng. XXXX, XXX, XXX−XXX

Letter

ACS Sustainable Chemistry & Engineering styrene derivatives.47−52 In this paper, we report the facile and scalable one-pot preparation of a series of protected VC monomers derived from naturally occurring caffeic acid via decarboxylation and protection (Scheme 1). The protected monomers were also amenable to various controlled polymerizations, including controlled radical and living anionic polymerizations.

is noteworthy that this simple one-pot reaction was applicable even on a large scale (25 g) and gave the protected monomers after the purification just through silica gel column in almost quantitative yield (51 g, 98%) (Figure S1 and Experimental Section in the Supporting Information). According to this procedure, a series of protected VCs was also obtained quantitatively by changing the trialkylsilyl chloride or using an acyl halide, as shown in Scheme 1 (Figure S2). Note that the low-molecular-weight monomers 1 and 5 could also be purified even by distillation. As summarized in Table 1, the protected VCs obtained from caffeic acid were polymerized via RAFT radical polymerization, as in the case of TES-protected VC from ferulic acid41 as well as nitroxide-mediated radical polymerization (NMP) and anionic polymerization using sec-BuLi as the initiator. For radical polymerizations, cumyl dithiobenzoate (CDB) was employed as the RAFT agent, and the styrene adduct of N(tert-butyl)-N-(isopropylphenylmethyl)nitroxide (TIPNO) was used as the mediator for NMP, as this system can efficiently control the radical polymerization of conventional styrene derivatives.53,54 The radical polymerizations of the protected VCs were successful, while those of unprotected VC only resulted in low molecular weight oligomers even in the free radical polymerization, which is probably due to radical transfer or electrophilic addition to the phenolic groups (Figure S3). As for the RAFT polymerization, most of the derivatives afforded well-defined polymers with relatively narrow molecular weight distributions (MWDs), in which the reaction rates were highly dependent on the bulkiness of the protecting group (Figures 2 and S4). With the less bulky trimethylsilyl(TMS: 1), triethylsilyl- (TES: 2), TBDMS (3), and acetyl (Ac: 5) groups, the polymerization reached almost quantitative conversion. In contrast, the bulkiest protecting group, triisopropylsilyl (TIPS: 4), resulted in a lower monomer conversion and boarder MWDs because the bulky substituent around the RAFT terminal disturbed the efficient reversible chain transfer during the RAFT process. The MWDs of poly(4) became slightly narrower when the initial monomer concentration was decreased (entry 10 in Table 1 and Figure S5). Except for 4, the SEC curves of the obtained polymers shifted to a high molecular weight region and retained their narrow MWDs as the polymerization proceeded. In particular, the polymers obtained from 2 and 3 had narrow MWDs and exhibited no bimolecular combination, which was observed in the SECs of polymers prepared from less bulky 1 and 5. This is consistent with a previous report in which bimolecular coupling was suppressed by bulky pendant groups.41 However, in most cases, the Mn values were lower than the values calculated assuming that one CDB molecule generates one living polymer chain, which is most likely due to the differences in their hydrodynamic volumes compared to standard polystyrenes. Actually, the Mn value of poly(2) measured by a multiangle laser light scattering (MALLS) detector agreed with the Mn determined by 1H NMR and theoretical values, as reported in the previous paper.41 Thus, the RAFT polymerizations of both silyl- and acetyl-protected VCs were successfully achieved, as in the case of monomers derived from ferulic acid. In addition, NMP with the TIPNO adduct was also effective in controlling the polymerization of styrene with a less bulky group (Mw/Mn = 1.1 for 2). Even with NMP via a dissociation−combination mechanism, the TIPS-

Scheme 1. One-Pot, Quantitative, and Scalable Synthesis of Protected Vinyl Catechol (VC)

■

RESULTS AND DISCUSSION The decarboxylation of caffeic acid was performed in DMF in the presence of triethylamine (Figure 1). Upon heating at 100

Figure 1. 1H NMR spectra (400 MHz, r.t.) of caffeic acid (A: DMSOd6), VC (B: DMSO-d6), and TBDMS2VC (3) (C: CDCl3).

°C, the reaction proceeded with concomitant release of CO2 gas. As shown in Figure 1B, VC was formed almost quantitatively by decarboxylation in 1 h, and the 1H NMR spectrum of the product exhibited peaks characteristic of a vinyl group (CH2CH−) at 5.0, 5.5, and 6.6 ppm, similar to those seen in conventional styrene derivatives. Immediately after decarboxylation, tert-butyldimethylsilyl (TBDMS) chloride was added to the reaction mixture at ambient temperature. After 24 h, the peak of the phenolic protons at 9.0 ppm disappeared and the signals of the vinyl groups remained intact (Figure 1C), which is similar to what is seen during the general procedures for the protection of hydroxyl groups in phenols. It B


Letter

ACS Sustainable Chemistry & Engineering Table 1. Polymerization of the Protected VCsa entry

monomer

initiating system

[M]0 (M)

[M]0/[I]0

temp (°C)

time (h)

convb(%)

Mn(calcd)c

Mnd

Mw/Mnd

1 2 3 4 5 6 7 8 9 10 11 12 13 14

TMS2VC (1) TMS2VC (1) TES2VC (2) TES2VC (2) TES2VC (2) TBDMS2VC (3) TBDMS2VC (3) TBDMS2VC (3) TIPS2VC (4) TIPS2VC (4) TIPS2VC (4) TIPS2VC (4) TIPS2VC (4) Ac2VC (5)

CDB/AIBN sec-BuLi CDB/AIBN St-TIPNO sec-BuLi CDB/AIBN sec-BuLi sec-BuLi CDB/AIBN CDB/AIBN St-TIPNO sec-BuLi sec-BuLi CDB/AIBN

2.0 0.5 2.0 2.5 0.5 2.0 0.5 0.5 2.0 0.5 2.0 0.5 0.5 2.0

100 50 100 100 50 100 50 50 100 100 100 50 50 100

60 −78 60 110 −78 60 −78 −40 60 60 110 −78 −40 60

192 3 36 56 3 36 3 12 72 720 26 6 240 96

95 0 95 91 0 97 99 99 78 81 93 87 98 97

26900 nd 34900 33500 n.d. 35600 18300 18300 35300 36600 42100 19500 22100 21600

19700 nd 20800 21500 n.d. 22100 14100 13100 22000 14100 26100 11400 28300 14200

1.10 nd 1.08 1.11 n.d. 1.06 1.04 1.04 4.87 1.40 1.71 1.10 6.57 1.14

a

Polymerization conditions: [M]0/[CDB]0/[AIBN]0 = 100/1.0/0.25 in toluene (entries 1, 3, 6, 10), ethyl acetate (entry 14), or bulk (entry 9) for RAFT polymerization. [M]0/[St-TIPNO]0 = 100/1.0 in bulk (entries 4, 11) for NMP. [M]0/[sec-BuLi]0 = 50/1.0 in THF (entries 2, 5, 7, 12) or methylcyclohexane containing 50 mM of THF (entries 8, 13) for anionic polymerization. bDetermined by 1H NMR. cMn(calcd) = MW(monomer) × ([M]0/[I]0) × conv + MW(initiator). dDetermined by SEC.

Figure 2. SEC curves of the polymers obtained in the RAFT polymerization of protected VCs (1−5): [M]0/[CDB]0/[AIBN]0 = 2000/20/5.0 mM in toluene (1−3), bulk (4), or ethyl acetate (5), at 60 °C.

bulkiness of the TIPS group (Figure S6). More interestingly, the polymers obtained from 4 in THF were partially insoluble in common solvents, such as THF, CHCl3, and n-hexane, which is most likely due to the difference in the stereoregularity of the polystyrene derivatives. The polymers thus obtained under various conditions were analyzed by 1H NMR spectroscopy (Figures S7 and S8). All of the protected polymers showed signals characteristic of welldefined structures, including peaks of the main chain, aromatic ring, and silyl substituents in addition to the peaks derived from the initiators, i.e., CDB and sec-BuLi. For further analysis, the polymers were deprotected using HCl or TBAF. As for the polymer obtained from 5, the acetate group was deprotected via alcoholysis under basic condition using KOH/ethanol. Importantly, in all cases, the unimodal shapes of the SEC curves did not change during the deprotection process retaining narrow MWDs. These results indicate that undesired reactions such as the coupling did not

protected monomer (4) also led to broader MWDs, similar to what is seen with RAFT polymerization (entry 11 in Table 1). The anionic polymerizations of protected VCs were examined using sec-butyllithium (sec-BuLi) as the initiator in THF at a lower temperature (entries 2, 5, 7, and 12 in Table 1 and Figure S6). In sharp contrast to the radical polymerization, the anionic polymerizations of 1 and 2 did not proceed at all, and the colors of the anionic species disappeared immediately after the reaction started. This is probably due to the deactivation of the generated carbanion by the nucleophilic attack to the less bulky silyl groups forming phenoxide anions. On the other hand, the monomers protected with rather bulky TBDMS (3) or TIPS (4) groups could be polymerized well in THF at −78 °C, which was also different from what was observed with RAFT radical polymerization. The anionic polymerizations of 3 and 4 afforded the living polymers with controlled molecular weights and narrow MWDs (Mw/Mn < 1.1), although 4 was consumed slower than 3 due to the C


Letter

ACS Sustainable Chemistry & Engineering

polymerization. The sharpness in 1H NMR signals varied slightly, most likely due to the stereoregularities. The bulkiness in protecting groups often affects on the stereoselectivity during polymerization, as seen in the case of silyl-protected methacrylic acid.55,56 The tacticities of the poly(VC)s obtained in this work could be roughly estimated based on the 13C NMR spectra despite the overlap in the peaks.57,58 Regardless of the protecting groups, the polymers obtained by radical polymerization exhibited almost atactic structures, in which the triad tacticity was close to the statistical values (mm/mr/rr = 25/50/25). In addition, the tacticities from the anionic polymerization of 3 were highly depended on the solvent: THF resulted in a higher isotactic content (mm = 50%), while methylcyclohexane with small amount of THF resulted in a very high syndiotactic content (rr = 79%). Though the effect was smaller, the tacticities of poly(4) by anionic polymerization were also dependent on the solvent to give higher isotactic contents in more polar solvents. Thus, various stereoregular poly(VC)s could be obtained by varying the polymerization conditions and the bulkiness of the silyl protecting groups. The thermal properties of poly(VC)s with various tacticities were also estimated by DSC. The Tg values of the syndiotactic and isotactic polymers were almost same as that of the atactic poly(VC) (Tg = 179 °C), and no crystalline behavior was observed.

occur under these mild conditions to produce well-defined poly(VC), which would be interesting in view of their functions such as adhesives and reductants (Figure S9). Figure 3 shows the 1H NMR and expanded 13C NMR spectra of the

■

CONCLUSIONS In conclusion, various protected VCs were easily obtained from naturally occurring caffeic acid by simple and scalable decarboxylation and protection reactions. The obtained monomers could be polymerized via radical and anionic polymerizations to afford well-defined polymers under appropriate conditions, and the tacticities of the products could be controlled by varying the conditions of the polymerizations and the silyl protecting groups on the monomers in the anionic polymerization. Methods of further controlling the stereoregularity as well as the practical properties of the resultant poly(VC)s as reductant, photoresist, and curing materials are now under investigation in our laboratory.

■

ASSOCIATED CONTENT

S Supporting Information *

The Supporting Information is available free of charge on the ACS Publications website at DOI: 10.1021/acssuschemeng.8b04400. Experimental procedures and supplementary data (PDF)

Figure 3. 1H (A) and 13C NMR (B) spectra ((CD3)2CO, 50 °C) of poly(VC)s obtained from radical and anionic polymerization of various protected VCs under various conditions followed by the deprotection. Anionic polymerization: [M]0/[sec-BuLi]0 = 500/10 mM in THF at −78 °C, in methylcyclohexane (containing 50 mM of THF) at −40 °C or in toluene at −40 °C. Radical polymerization: [M]0/[CDB]0/[AIBN]0 = 2000/20/5.0 mM (for 1, 2, 3) or 1000/ 10/2.5 mM (for 4) in toluene at 60 °C.

■

AUTHOR INFORMATION

Corresponding Authors

*E-mail: [email protected]. *E-mail: [email protected]. ORCID

Kotaro Satoh: 0000-0002-3105-4592 Masami Kamigaito: 0000-0001-7584-5524

ipso-carbon of a series of poly(VC)s obtained after the deprotection of the silyl groups. The Mn values [Mn(NMR)] of the anionically polymerized polymers, which were calculated by the peak intensity ratio of the phenyl protons (c) to the methyl groups derived from sec-BuLi initiator (α), were close to the theoretical values from the monomer-to-initiator ratio, which also suggests that all of the polymer chains were generated from the initiator molecule via living anionic

Notes

The authors declare no competing financial interest.

■

ACKNOWLEDGMENTS This work was supported in part by JSPS Research Fellowships for Young Scientists for H.T. (No. 18J15251) and Program for D


Letter

ACS Sustainable Chemistry & Engineering Leading Graduate Schools “Integrative Graduate Education and Research Program in Green Natural Sciences”.

■

(24) Lee, H.; Dellatore, S. M.; Miller, W. M.; Messersmith, P. B. Mussel-Inspired Surface Chemistry for Multifunctional Coatings. Science 2007, 318, 426−430. (25) Heo, J.; Kang, T.; Jang, S. G.; Hwang, D. S.; Spruell, J. M.; Killops, K. L.; Waite, J. H.; Hawker, C. J. Improved Performance of Protected Catecholic Polysiloxanes for Bioinspired Wet Adhesion to Surface Oxides. J. Am. Chem. Soc. 2012, 134, 20139−20145. (26) Patil, N.; Jérôme, C.; Detrembleur, C. Recent advances in the synthesis of catechol-derived (bio)polymers for applications in energy storage and environment. Prog. Polym. Sci. 2018, 82, 34−91. (27) Lee, H.; Lee, B. P.; Messersmith, P. B. A reversible wet/dry adhesive inspired by mussels and geckos. Nature 2007, 448, 338−341. (28) Xu, H.; Nishida, J.; Ma, W.; Wu, H.; Kobayashi, M.; Otsuka, H.; Takahara, A. Competition between Oxidation and Coordination in Cross-linking of Polystyrene Copolymer Containing Catechol Groups. ACS Macro Lett. 2012, 1, 457−460. (29) Patil, N.; Falentin-Daudré, C.; Jérôme, C.; Detrembleur, C. Mussel-inspired protein-repelling ambivalent block copolymers: controlled synthesis and characterization. Polym. Chem. 2015, 6, 2919−2933. (30) Iwabuchi, S.; Nakahira, T.; Inohana, A.; Uchida, H.; Kojima, K. Polymeric catechol derivatives. IV. Polymerization behavior of 4vinylcatechols and some properties of their polymeric derivatives. J. Polym. Sci., Polym. Chem. Ed. 1983, 21, 1877−1884. (31) Daly, W. H.; Moulay, S. Synthesis of poly(vinylcatechols). J. Polym. Sci., Polym. Symp. 1986, 74, 227−242. (32) Ishizone, T.; Mochizuki, A.; Hirao, A.; Nakahama, S. Protection and Polymerization of Functional Monomers. 24. Anionic Living Polymerizations of 5-Vinyl- and 4-Vinyl-1,3-benzodioxoles. Macromolecules 1995, 28, 3787−3793. (33) Westwood, G.; Horton, T. N.; Wilker, J. J. Simplified Polymer Mimics of Cross-Linking Adhesive Proteins. Macromolecules 2007, 40, 3960−3964. (34) White, J. D.; Wilker, J. J. Underwater Bonding with Charged Polymer Mimics of Marine Mussel Adhesive Proteins. Macromolecules 2011, 44, 5085−5088. (35) Matos-Pérez, C. R.; White, J. D.; Wilker, J. J. Polymer Composition and Substrate Influences on the Adhesive Bonding of a Biomimetic, Cross-Linking Polymer. J. Am. Chem. Soc. 2012, 134, 9498−9505. (36) Isakova, A.; Topham, P. D.; Sutherland, A. J. Controlled RAFT Polymerization and Zinc Binding Performance of Catechol-Inspired Homopolymers. Macromolecules 2014, 47, 2561−2568. (37) Saito, Y.; Yabu, H. Synthesis of poly(dihydroxystyrene-blockstyrene) (PDHSt-b-PSt) by the RAFT process and preparation of organic-solvent-dispersive Ag NPs by automatic reduction of metal ions in the presence of PDHSt-b-PSt. Chem. Commun. 2015, 51, 3743−3746. (38) Saito, Y.; Higuchi, T.; Jinnai, H.; Hara, M.; Nagano, S.; Matsuo, Y.; Yabu, H. Silver Nanoparticle Arrays Prepared by In Situ Automatic Reduction of Silver Ions in Mussel-Inspired Block Copolymer Films. Macromol. Chem. Phys. 2016, 217, 726−734. (39) Leibig, D.; Müller, A. H. E.; Frey, H. Anionic Polymerization of Vinylcatechol Derivatives: Reversal of the Monomer Gradient Directed by the Position of the Catechol Moiety in the Copolymerization with Styrene. Macromolecules 2016, 49, 4792− 4801. (40) Leibig, D.; Lange, A. K.; Birke, A.; Frey, H. Capitalizing on Protecting Groups to Influence Vinyl Catechol Monomer Reactivity and Monomer Gradient in Carbanionic Copolymerization. Macromol. Chem. Phys. 2017, 218, 1600553. (41) Takeshima, H.; Satoh, K.; Kamigaito, M. Bio-Based Functional Styrene Monomers Derived from Naturally Occurring Ferulic Acid for Poly(vinylcatechol) and Poly(vinylguaiacol) via Controlled Radical Polymerization. Macromolecules 2017, 50, 4206−4216. (42) Herrmann, K. Flavonols and flavones in food plants: a review. Int. J. Food Sci. Technol. 1976, 11, 433−438.

REFERENCES

(1) Ito, H.; Willson, C. G. Applications of Photoinitiators to the Design of Resists for Semiconductor Manufacturing. Polymers in Electronics 1984, 242, 11−23. (2) Nakahama, S.; Hirao, A. Protection and polymerization of functional monomers: Anionic living polymerization of protected monomers. Prog. Polym. Sci. 1990, 15, 299−335. (3) Gao, B.; Chen, X.; Iván, B.; Kops, J.; Batsberg, W. Living atom transfer radical polymerization of 4-acetoxystyrene. Macromol. Rapid Commun. 1997, 18, 1095−1100. (4) Tuck, C. O.; Peŕez, E.; Horvath, I. T.; Sheldon, R. A.; Poliakoff, M. Valorization of Biomass: Deriving More Value from Waste. Science 2012, 337, 695−699. (5) Klass, D. L. Biomass for Renewable Energy, Fuels, and Chemicals 1998, DOI: 10.1016/B978-0-12-410950-6.X5000-4. (6) Wool, P. R.; Sun, X. S. Bio-Based Polymers and Composites 2005, DOI: 10.1016/B978-0-12-763952-9.X5000-X. (7) Gandini, A.; Belgacem, M. N. Monomers, Polymers and Composites from Renewable Resources 2008, DOI: 10.1016/B978-008-045316-3.X0001-4. (8) Mathers, R. T.; Meier, M. A. R. Green Polymerization Methods: Renewable Starting Materials, Catalysis and Waste Reduction 2011, DOI: 10.1002/9783527636167. (9) Kamigaito, M.; Satoh, K.; Tang, C.; Ryu, C. Y. Sustainable Vinyl Polymers via Controlled Polymerization of Terpenes. Sustainable Polymers from Biomass 2017, 55−90. (10) Kamigaito, M.; Satoh, K.; Kobayashi, S.; Müllen, K. Bio-based Hydrocarbon Polymers. Encyclopedia of Polymeric Nanomaterials 2015, 1, 109−118. (11) Satoh, K.; Kamigaito, M. New Polymerization Methods for Biobased Polymers. In Bio-Based Polymers; Kimura, Y., Ed.; CMC: Tokyo, 2013; pp 95−111, ISBN 978-4-7813-0271-3. (12) Yao, K.; Tang, C. Controlled Polymerization of NextGeneration Renewable Monomers and Beyond. Macromolecules 2013, 46, 1689−1712. (13) Mülhaupt, R. Green Polymer Chemistry and Bio-based Plastics: Dreams and Reality. Macromol. Chem. Phys. 2013, 214, 159−174. (14) Miller, S. A. Sustainable Polymers: Opportunities for the Next Decade. ACS Macro Lett. 2013, 2, 550−554. (15) Hillmyer, M. A.; Tolman, W. B. Aliphatic Polyester Block Polymers: Renewable, Degradable, and Sustainable. Acc. Chem. Res. 2014, 47, 2390−2396. (16) Holmberg, A. L.; Reno, K. H.; Wool, R. P.; Epps, T. H. III Biobased building blocks for the rational design of renewable block polymers. Soft Matter 2014, 10, 7405−7424. (17) Zhu, Y.; Romain, C.; Williams, C. K. Sustainable polymers from renewable resources. Nature 2016, 540, 354−362. (18) Llevot, A.; Dannecker, P.-K.; von Czapiewski, M.; Over, L. C.; Söyler, Z.; Meier, M. A. R. Renewability is not Enough: Recent Advances in the Sustainable Synthesis of Biomass-Derived Monomers and Polymers. Chem. - Eur. J. 2016, 22, 11510−11521. (19) Thomsett, M. R.; Storr, T. E.; Monaghan, O. R.; Stockman, R. A.; Howdle, S. M. Progress in the sustainable polymers from terpenes and terpenoids. Green Mater. 2016, 4, 115−134. (20) Schneiderman, D. K.; Hillmyer, M. A. There is a Great Future in Sustainable Polymers. Macromolecules 2017, 50, 3733−3749. (21) Kim, E.; Liu, Y.; Leverage, W. T.; Yin, J.-J.; White, I. M.; Bentley, W. E.; Payne, G. F. Context-Dependent Redox Properties of Natural Phenolic Materials. Biomacromolecules 2014, 15, 1653−1662. (22) Watanabe, H.; Fujimoto, A.; Takahara, A. Characterization of Catechol-Containing Natural Thermosetting Polymer “Urushiol” Thin Film. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 3688−3692. (23) Waite, J. H.; Tanzer, M. L. Polyphenolic Substance of Mytilus edulis: Novel Adhesive Containing L-Dopa and Hydroxyproline. Science 1981, 212, 1038−1040. E


Letter

ACS Sustainable Chemistry & Engineering (43) Niggeweg, R.; Michael, A. J.; Martin, C. Engineering plants with increased levels of the antioxidant chlorogenic acid. Nat. Biotechnol. 2004, 22, 746−754. (44) Olthof, M. R.; Hollman, P. C.; Katan, M. B. Chlorogenic Acid and Caffeic Acid Are Absorbed in Humans. J. Nutr. 2001, 131, 66− 71. (45) Kaneko, T.; Thi, T. H.; Shi, D. J.; Akashi, M. Environmentally degradable high-performance thermoplastics from phenolic phytomonomers. Nat. Mater. 2006, 5, 966−970. (46) Ishii, D.; Maeda, H.; Hayashi, H.; Mitani, T.; Shinohara, N.; Yoshioka, K.; Watanabe, T. Effect of Polycondensation Conditions on Structure and Thermal Properties of Poly(caffeic acid). ACS Symp. Ser. 2013, 1144, 237−249. (47) Sovish, R. Preparation and Polymerization of p-Vinylphenol. J. Org. Chem. 1959, 24, 1345−1347. (48) Cohen, L. A.; Jones, W. M. A Study of pH Dependence in the Decarboxylation of p-Hydroxycinnamic Acid. J. Am. Chem. Soc. 1960, 82, 1907−1911. (49) Hatakeyama, H.; Hayashi, E.; Haraguchi, T. Biodegradation of poly(3-methoxy-4-hydroxy styrene). Polymer 1977, 18, 759−763. (50) Takemoto, M.; Achiwa, K. Synthesis of Styrenes through the Biocatalytic Decarboxylation of trans-Cinnamic Acids by Plant Cell Cultures. Chem. Pharm. Bull. 2001, 49, 639−641. (51) Nomura, E.; Hosoda, A.; Mori, H.; Taniguchi, H. Rapid basecatalyzed decarboxylation and amide-forming reaction of substituted cinnamic acids via microwave heating. Green Chem. 2005, 7, 863− 866. (52) Liu, D.; Sun, J.; Simmons, B. A.; Singh, S. N-Heterocyclic Carbene Promoted Decarboxylation of Lignin-Derived Aromatic Acids. ACS Sustainable Chem. Eng. 2018, 6, 7232−7238. (53) Moad, G.; Rizzardo, E.; Thang, A. H. Living Radical Polymerization by the RAFT Process. Aust. J. Chem. 2005, 58, 379−410. (54) Nicolas, J.; Guillaneuf, Y.; Lefay, C.; Bertin, D.; Gigmes, D.; Charleux, B. Nitroxide-mediated polymerization. Prog. Polym. Sci. 2013, 38, 63−235. (55) Ishitake, K.; Satoh, K.; Kamigaito, M.; Okamoto, Y. Stereospecific Free Radical and RAFT Polymerization of Bulky Silyl Methacrylates for Tacticity and Molecular Weight Controlled Poly(methacrylic acid). Macromolecules 2011, 44, 9108−9117. (56) Ishitake, K.; Satoh, K.; Kamigaito, M.; Okamoto, Y. Asymmetric Anionic Polymerization of Tris(trimethylsilyl)silyl Methacrylate: A Highly Isotactic Helical Chiral Polymer. Polym. J. 2013, 45, 676−680. (57) Inoue, Y.; Nishioka, A.; Chujo, R. Carbon-13 Nuclear Magnetic Resonance Spectroscopy of Polystyrene and Poly-α-methylstyrene. Makromol. Chem. 1972, 156, 207−223. (58) Matsuzaki, K.; Uryu, T.; Osada, K.; Kawamura, T. Stereoregularity of Polystyrene Determined by Carbon-13 Nuclear Magnetic Resonance Spectroscopy. Macromolecules 1972, 5, 816−818.

F


Protected Vinyl Catechol from Caffeic Acid and ... - ACS Publications

Recommend Documents