Improvements in the Synthesis of Phenylacetylene Monodendrons Including a Solid-Phase Convergent Method

Bharathi, Pandi; Patel, Umesh; Kawaguchi, Tohru; Pesak, Douglas J.; Moore, Jeffrey S.

doi:10.1021/ma00121a037

Cited by 84 publications

(58 citation statements)

References 2 publications

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“…Within the structure, a single branch is called a dendron. Additionally, the synthesis and the choice of monomers is highly flexible, since these macromolecules are synthesized in a repetitive manner by either a divergent, [29][30][31][32] (from core to periphery) or convergent, 28,[33][34][35][36] (from periphery to core) approach. An illustration of a divergent synthetic approach is shown in Figure 2, where a monomer is added to core using a series of step-wise coupling and deprotection reactions.…”

Section: Dendrimersmentioning

confidence: 99%

Designing hydrogel adhesives for corneal wound repair

2007

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Today, corneal wounds are repaired using nylon sutures. Yet there are a number of complications associated with suturing the cornea, and thus there is interest in an adhesive to replace or supplement sutures in the repair of corneal wounds. We are designing and evaluating corneal adhesives prepared from dendrimers -single molecular weight, highly branched polymers. We have explored two strategies to form these ocular adhesives. The first involves a photocrosslinking reaction and the second uses a peptide ligation reactions to couple the individual dendrimers together to from the adhesive. These adhesives were successfully used to repair corneal perforations, close the flap produced in a LASIK procedure, and secure a corneal transplant.

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Section: Dendrimersmentioning

confidence: 99%

Designing hydrogel adhesives for corneal wound repair

2007

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“…Dendrimers containing photoactive units [7][8][9][10][11][12][13][14][15][16][17] are particularly interesting for two reasons: (1) cooperation among the photoactive components can allow the dendrimer to perform specific functions, and (2) changes in the properties of photoactive components can be exploited to monitor the participation of dendrimers in chemical processes.…”

Section: -6mentioning

confidence: 99%

Synthesis of Poly(3,4,5-trihydroxybenzoate amide) and Poly(3,4,5-trihydroxybenzoate ester) Dendrimers from Polyphenols and Their Chemiluminescence

Lee¹,

Song²,

Lee³

et al. 2012

Bulletin of the Korean Chemical Society

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Dendrimer chemistry is rapidly expanding for fundamental reasons as well as due to requirements in technological applications.1 A recent interesting development in dendrimer chemistry concerns the coordination of metal ions by interior branches or exterior units. 2-6Dendrimers containing photoactive units 7-17 are particularly interesting for two reasons: (1) cooperation among the photoactive components can allow the dendrimer to perform specific functions, and (2) changes in the properties of photoactive components can be exploited to monitor the participation of dendrimers in chemical processes.Polyphenols such as pyrogallol and gallic acid (GA) produce a singlet oxygen in the presence of hydrogen peroxide in an alkaline medium and emit light. GA has also been utilized for selective Co 2+ detection using a chemiluminescence (CL) flow injection system. The CL intensities of polyphenols are considerably weaker than those of luminal and acridinium ester, which are representative CL compounds. Hence, trans-4-(3-propionic acid) phenylboronic acid and 4-biphenylboronic acid in the presence of peroxidase or 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide have been used as an enhancer for highly sensitive polyphenol CL determination. However, methods to derive polyphenols with strong CL intensity have not been reported yet. 18In recent times, after a new polymer, poly(amidoamine) dendrimer, was synthesized, dendrimers have been applied to material engineering based on optics in nanoscale science. The poly(propylene amine) family that was functionalized in the periphery with fluorescent dansyl units interacts with Co 2+. More recently, acridinium dendrimers have been conjugated with bovine serum albumin, and its CL was estimated to be six times that of the acridinium salt.In this paper, we report the design of new types of polyphenol dendrimers having an increased number of chemiluminophores for high CL intensity; they also have hydroxyl groups in their periphery to form hydrogen bonds with an analyte. Polyphenol dendrimers having GA in the periphery were synthesized, and their CL was measured. We synthesized first-generation polyphenol dendrimers with GA units in the periphery by employing a divergent method using phenol, pyrocatechol, resorcinol, hydroquinone, 1,2,4-trihydroxybenzene, 3,4,5-trihydroxybenzene aniline, 1,2-diaminobenzene, and 1,3-diaminobenzene as the core molecules (Supporting information, Schemes 1 and 2).Experimental methods and physical data from polyol 1a-f to first-generation esters 5a-f have been reported in our previous paper. 19The mass spectra of the zero-generation esters 3a-f and first-generation esters 5a-5f were obtained by matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI TOF MS) using 2,5-dihydroxybenzoic acid as the matrix. The amide group has a rigid, planer structure as a consequence of resonance interactions that give the amide bond ~40% double bond character. The planer conformation maximizes π-bonding overlap, which accounts for the amide group's ri...

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“…In a single report by Moore et al, 51 a convergent approach was used for dendron synthesis. According to this strategy, each generation assembly on the support is followed by dendron cleavage and coupling of the cleaved dendritic wedge to the resin-bound monomer; this forms the next generation (Scheme 13).…”

Section: Convergent Approachmentioning

confidence: 99%

Dendrons and dendritic catalysts immobilized on solid support: Synthesis and dendritic effects in catalysis

Dahan

Portnoy

2004

J. Polym. Sci. A Polym. Chem.

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Dendrimers, the aesthetically beautiful macromolecules displaying a variety of potentially useful architecture-induced properties, are traditionally assembled in solution. However, since 1988, a number of dendritic structures have been assembled on insoluble organic and inorganic polymers, and thus dendronized supports have been formed. One of the major applications of these new materials is in the field of heterogeneous catalysis. Supported dendritic catalytic systems, bearing the catalytic units on the dendron periphery, have been examined in the last 5 years in such reactions as hydroformylation, Heck and other Pd-catalyzed COC bond formations, oxidation, and enantioselective addition to aldehydes. In the majority of these studies, substantial dendritic effects on the reactivity, selectivity, or recyclability of the catalysts were observed. Although a number of factors have been suggested as sources of the effects, it is most likely that the phenomenon has a multicomponent origin. Additional research, including a full determination of the effects and their causes, is likely to lead to markedly better heterogeneous catalytic systems.

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Improvements in the Synthesis of Phenylacetylene Monodendrons Including a Solid-Phase Convergent Method

Cited by 84 publications

References 2 publications

Designing hydrogel adhesives for corneal wound repair

Designing hydrogel adhesives for corneal wound repair

Synthesis of Poly(3,4,5-trihydroxybenzoate amide) and Poly(3,4,5-trihydroxybenzoate ester) Dendrimers from Polyphenols and Their Chemiluminescence

Dendrons and dendritic catalysts immobilized on solid support: Synthesis and dendritic effects in catalysis

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