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Masakatsu Matsumoto - One of the best experts on this subject based on the ideXlab platform.
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organic superbase induced chemiluminescent decomposition of a hydroxyaryl substituted Dioxetane unique effect of a bifunctional guanidine base on the chemiluminescence profile of a bicyclic Dioxetane bearing a 4 benzoxazol 2 yl 3 5 dihydroxyphenyl mo
Tetrahedron Letters, 2018Co-Authors: Nobuko Watanabe, Hisako K. Ijuin, Ayu Wakatsuki, Yoshio Kabe, Masakatsu MatsumotoAbstract:Abstract Organic superbases represented by TBD (1,5,7-triazabicyclo[4.4.0]dec-5-ene) effectively induced the decomposition of hydroxyaryl-substituted Dioxetanes in acetonitrile to give bright light. The color of the chemiluminescence from a Dioxetane bearing a 4-(benzoxazol-2-yl)-3,5-dihydroxyphenyl moiety varied depending on the base used. In addition to this change in the color of emission, TBD increased the chemiluminescence efficiency 2- to 5-fold compared to the results with other base systems and accelerated decomposition of the Dioxetane. These unique effects of TBD may be due to its “bifunctional” character, which is different from those of other organic superbases. Chemiluminescent decomposition of the Dioxetane was effectively induced by superbases even in apolar p-xylene.
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N -Acyl group-directed color modulation in the t -BuOK-mediated chemiluminescent decomposition of hydroxyaryl-substituted Dioxetanes fused with a pyrrolidine ring
Tetrahedron Letters, 2012Co-Authors: Nobuko Watanabe, Hisako K. Ijuin, Haruna Suzuki, Kairi Matsumoto, Teruhiko Tanaka, Masakatsu MatsumotoAbstract:Abstract Bicyclic Dioxetanes, 1-(hydroxyaryl)-2-aza-6,7-dioxabicyclo[3.2.0]heptanes, bearing a syn-N-acyl or anti-N-acyl group underwent TBAF (tetrabutylammonium fluoride)-induced decomposition in DMSO or THF accompanied by the emission of bright light, the maximum wavelengths ( λ max CL ) of which were similar to each other. On the other hand, upon treatment with t-BuOK in THF, the Dioxetanes bearing a syn-N-acyl group emitted light that showed a dramatic red-shift compared to that in a TBAF/THF system, while the Dioxetanes bearing an anti-N-acyl group showed light with a blue-shift. For oxidoaryl-substituted Dioxetanes bearing a syn-N-acyl group, t-BuOK most likely coordinated with both a syn-N-acyl and an oxygen of the Dioxetane ring, so that two imide carbonyls in the produced emitter possessed a considerably regulated structure leading to a red-shift in the chemiluminescence. Such coordination of K+ was hardly expected for the case of the Dioxetanes bearing an anti-N-acyl group, for which the strong contact of K+ to an oxidoaryl group presumably caused a blue-shift in chemiluminescence.
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Synthesis of Thermally Stable Acylamino-Substituted Bicyclic Dioxetanes and Their Base-Induced Chemiluminescent Decomposition
The Journal of organic chemistry, 2010Co-Authors: Nobuko Watanabe, Hisako K. Ijuin, Yusuke Sano, Haruna Suzuki, Masatoshi Tanimura, Masakatsu MatsumotoAbstract:Hydroxyaryl-substituted Dioxetanes 2−4 fused with a pyrrolidine ring were selectively synthesized by singlet oxygenation of the corresponding dihydropyrroles 5−7. These N-acylamino-substituted bicyclic Dioxetanes were quite stable thermally, and 2a and 2b were estimated to possess half-lives of 32 and 34 y at 25 °C. When treated with TBAF (tetrabutylammonium fluoride) in DMSO, these Dioxetanes underwent charge-transfer-induced decomposition (CTID) to emit yellow−orange light. The chemiluminescence efficiencies ΦCL for Dioxetanes 2 ranged from 10−6 to 10−2. On the other hand, Dioxetane 4 bearing a 4-(benzothiazol-2-yl)-3-hydroxyphenyl moiety showed chemiluminescent decomposition with high efficiency (ΦCL = 0.15) comparable to its oxy-analogue 26. Prominent characteristics for CTID of the present Dioxetanes were that the N-acylamino-group influenced the color of chemiluminescence as well as the rate of decomposition kCTID, and furthermore an N-acyl substituent could decisively affect the singlet-chemiexcita...
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Synthesis of sulfanyl-, sulfinyl-, and sulfonyl-substituted bicyclic Dioxetanes and their base-induced chemiluminescence.
Journal of Organic Chemistry, 2010Co-Authors: Nobuko Watanabe, Yuusuke Maniwa, Hisako K. Ijuin, Masato Kikuchi, Masakatsu MatsumotoAbstract:The singlet oxygenation of 4-tert-butyl-3,3-dimethyl-5-(3-oxyphenyl)-2,3-dihydrothiophenes 5c−e bearing an acetoxy or methoxy group at the 2-position exclusively gave the corresponding sulfanyl-substituted bicyclic Dioxetanes 2c−e, while that of 5a without 2-substituent mainly gave sulfoxide 11 along with a small amount of Dioxetane 2a. These Dioxetanes were sufficiently stable thermally to permit handling at room temperature. Sulfanyl-substituted Dioxetanes, 2c and 2e, were further oxidized with m-chloroperbenzoic acid to afford the corresponding sulfinyl-substituted Dioxetanes 3c, 3e and sulfonyl-substituted Dioxetanes 4c, 4e. X-ray single crystallographic analysis was performed for 2c and 4e. Base-induced decomposition of the Dioxetanes in DMSO gave light with a maximum wavelength λmaxCL at 554 nm for 2a and 565 nm for 2e in moderate light yields, while sulfinyl-derivative 3e gave weak light with λmaxCL = 795 nm and sulfonyl-derivative 4e gave very weak light with λmaxCL = 848 nm.
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Alkaline metal ion-enhanced chemiluminescence of bicyclic Dioxetanes bearing a hydroxyaryl group with an ‘ even ’ substitution pattern
Tetrahedron Letters, 2009Co-Authors: Masakatsu Matsumoto, Nobuko Watanabe, Fumihiko Kakuno, Aoi Kikkawa, Naoyuki Hoshiya, Hisako K. IjuinAbstract:Bicyclic Dioxetane 5 bearing a 3-hydroxynaphthalen-2-yl group and its analogs 14 and 15 decomposed to give light with efficiencies of only 0.002–0.005% in a tetrabutylammonium fluoride (TBAF)/THF system, which was as expected for Dioxetanes with a so-called ‘ even ’ substitution pattern. However, the chemiluminescence efficiencies ( Φ CL ) markedly increased when these Dioxetanes were decomposed with alkaline metal t- butoxide in THF. This enhancement of Φ CL by alkaline metal ion was most likely due to the highly ordered conformation of an aromatic ring by chelate formation of the metal ion with both an oxido anion and oxygen atom of a tetrahydrofuran ring in an intermediary Dioxetane like 12 . Alkaline metal ion-enhanced chemiluminescence was similarly observed for Dioxetane 6 bearing a 2-hydroxyphenyl group.
Waldemar Adam - One of the best experts on this subject based on the ideXlab platform.
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contemporary trends in Dioxetane chemistry
Patai's Chemistry of Functional Groups, 2009Co-Authors: Waldemar Adam, Alexei V TrofimovAbstract:1 Introduction 2 Stereoselective Synthesis of Chiral Dioxetanes and their Transformations 3 α-Peroxy Lactone as Oxidant 4 Chemiluminescent Decomposition of 1,2-Dioxetanes 5 Bioanalytical Application of the Dioxetane Chemiluminescence 6 Photooxidation of DNA by 1,2-Dioxetanes 7 Conclusions 8 Acknowledgment Keywords: Dioxetanes and dioxetanones - four-membered-ring cyclic peroxides; chiral Dioxetane stereoselective synthesis; geminate chiral radical pair; α-peroxy lactone as oxidant; four-membered-ring cyclic congeners; cleavage of 1,2-Dioxetanes - model chemiluminescent process; Chemically Initiated Electron-exchange Luminescence (CIEEL); DNA and 1,2-Dioxetane photooxidation
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The Thermal Decomposition of 1,2-Dioxetane Revisited
The Journal of Physical Chemistry A, 1999Co-Authors: Sarah Wilsey, Fernando Bernardi, Massimo Olivucci, Michael A. Robb, Sean Murphy, Waldemar AdamAbstract:The ground state (S0) and lowest energy triplet state (T1) energy surfaces of the parent Dioxetane have been extensively explored using various CASSCF active spaces with MP2 corrections in several basis sets. In particular, the singlet/triplet surface crossing regions have been examined and the spin−orbit coupling and energetics computed. The computed energy barrier for the ring-opening of Dioxetane is 16 kcal mol-1, which is lower than the experimentally observed threshold (22 kcal mol-1) for unsubstituted Dioxetane decomposition. However, the surface topology is in good agreement with the experimental observations. The barrier for O−O cleavage on the ground state surface is found to lie at nearly the same energy as the transition structure for C−C biradical cleavage on the triplet energy surface. More significantly, the computational results indicate that the singlet and triplet surfaces do not cross along the minimum energy path (MEP) between the ground state O−O cleavage transition state and the singl...
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Fluoride‐ and Base‐Induced Chemiluminescence (CIEEL) of a Bifunctional Spiroacridane‐Substituted Dioxetane
Liebigs Annalen, 1997Co-Authors: Waldemar Adam, Dirk ReinhardtAbstract:The intramolecular chemically initiated electron-exchange luminescence (CIEEL) of the novel bifunctional Dioxetane 2b was studied. By selective chemical triggering, two different functionalities, namely either a phenoxy (ArO−) or an amide (Ar2N−) ion electron donor, were released, dependent on the type of triggering agent used (either base or fluoride ions). From the CIEEL quantum yields (ΦCIEEL) for the triggered chemiluminescence and the fluorescence efficiencies (ΦFl) of the corresponding phenolate (7) and amide (5) emitters the singlet-excitation yields (ΦS) were estimated. Due to the weak fluorescence emission and the low excitation propensity, the triggerable bifunctional Dioxetane 2b constitutes an inefficient CIEEL system. For comparison, the activation parameters (EA, lg A, ΔH≠, ΔS≠) of the direct chemiluminescence in the thermal decomposition of the Dioxetane 2a were determined by standard isothermal kinetic methods.
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from the firefly bioluminescence to the Dioxetane based amppd chemiluminescence immunoassay a retroanalysis
Analyst, 1996Co-Authors: Waldemar Adam, Dirk Reinhardt, Chantu R SahamollerAbstract:Chemiluminescent Dioxetanes, which are enzymically triggerable, have proved to be a valuable tool in diagnostic clinical applications. In this context, the phenomenon of firefly bioluminescence (the most efficient light-producing system so far) has served as an excellent example to develop new chemiluminescent probes for bioanalysis, in particular chemiluminescence immunoassays. From the recognition of the molecular details of the firefly bioluminescence, a chemical equivalent has been conceived which possesses the essential features for efficient generation of light, i.e., thermal persistence through spiroadamantyl substitution, spontaneous chemically initiated electron exchange luminescence (CIEEL)-active decomposition after enzymic triggering, efficient light emission as a lasting glow and convenient synthesis by photooxygenation. This has led to a rationally designed Dioxetane, namely the 3-(2′-spiroadamantyl)-4-methoxy-4-(3″-phosphoryloxy)-phenyl-1,2-Dioxetane (AMPPD) derivative, which serves as a substrate for alkaline phosphatase and, in terms of sensitivity, has surpassed the hazardous radioactive immunoassay probes. This paper gives a historical account in the form of a retroanalysis of the success story behind the rational design of the first enzymically triggerable, CIEEL-active AMPPD chemiluminescent probe.
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Chemically Initiated Electron Exchange Luminescence of Silyloxyaryl‐Substituted Spiroadamantyl Dioxetanes: Kinetics and Excited State Yields
Photochemistry and Photobiology, 1996Co-Authors: Alexei V Trofimov, Karsten Mielke, R. F. Vasil'ev, Waldemar AdamAbstract:— The kinetics of the fluoride-induced decomposition of the thermally stable silyloxyaryl-substituted spiroadamantyl Dioxetanes 1a,b and the excited state formation of this chemically initiated electron exchange luminescence (CIEEL) have been investigated. Two limiting kinetic regimes flash and glow have been identified, which depend on the fluoride concentration, the first at high, the second at low [F-] triggering, whose detailed kinetic analysis affords the rate constants for the deprotected Dioxetanes 2a,b cleavage in acetonitrile and dimethyl sulfoxide and chemiluminescence measurements the CIEEL and phen-olate 4 (CIEEL emitter) excitation yields. Chloro-substi-tution in the spiroadamantyl Dioxetane does not affect the deprotection step k2 but leads to a ca five-fold faster cleavage of the deprotected Dioxetane 2, while the chemiexcitation yield is the same for both Dioxetanes. The energies of the first excited singlet and triplet states of the emitting phenolate 4 were estimated by AM1 configuration interaction calculations with explicit consideration of acetonitrile as solvent (self-consistent reaction field approach). The first excited singlet and triplet state of the CIEEL emitter phenolate 4 possess π,π* character, as suggested by the π-type molecular orbitals and the large singlet-triplet energy gap. The chemiexcitation of both singlet and triplet states of the excited phenolate 4 is feasible during the Dioxetanes 1a,b cleavage, but the experimentally determined high singlet excitation yields suggest that preferentially the phenolate 4 singlet state is populated in the fluoride ion-triggered CIEEL process.
Nobuko Watanabe - One of the best experts on this subject based on the ideXlab platform.
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organic superbase induced chemiluminescent decomposition of a hydroxyaryl substituted Dioxetane unique effect of a bifunctional guanidine base on the chemiluminescence profile of a bicyclic Dioxetane bearing a 4 benzoxazol 2 yl 3 5 dihydroxyphenyl mo
Tetrahedron Letters, 2018Co-Authors: Nobuko Watanabe, Hisako K. Ijuin, Ayu Wakatsuki, Yoshio Kabe, Masakatsu MatsumotoAbstract:Abstract Organic superbases represented by TBD (1,5,7-triazabicyclo[4.4.0]dec-5-ene) effectively induced the decomposition of hydroxyaryl-substituted Dioxetanes in acetonitrile to give bright light. The color of the chemiluminescence from a Dioxetane bearing a 4-(benzoxazol-2-yl)-3,5-dihydroxyphenyl moiety varied depending on the base used. In addition to this change in the color of emission, TBD increased the chemiluminescence efficiency 2- to 5-fold compared to the results with other base systems and accelerated decomposition of the Dioxetane. These unique effects of TBD may be due to its “bifunctional” character, which is different from those of other organic superbases. Chemiluminescent decomposition of the Dioxetane was effectively induced by superbases even in apolar p-xylene.
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N -Acyl group-directed color modulation in the t -BuOK-mediated chemiluminescent decomposition of hydroxyaryl-substituted Dioxetanes fused with a pyrrolidine ring
Tetrahedron Letters, 2012Co-Authors: Nobuko Watanabe, Hisako K. Ijuin, Haruna Suzuki, Kairi Matsumoto, Teruhiko Tanaka, Masakatsu MatsumotoAbstract:Abstract Bicyclic Dioxetanes, 1-(hydroxyaryl)-2-aza-6,7-dioxabicyclo[3.2.0]heptanes, bearing a syn-N-acyl or anti-N-acyl group underwent TBAF (tetrabutylammonium fluoride)-induced decomposition in DMSO or THF accompanied by the emission of bright light, the maximum wavelengths ( λ max CL ) of which were similar to each other. On the other hand, upon treatment with t-BuOK in THF, the Dioxetanes bearing a syn-N-acyl group emitted light that showed a dramatic red-shift compared to that in a TBAF/THF system, while the Dioxetanes bearing an anti-N-acyl group showed light with a blue-shift. For oxidoaryl-substituted Dioxetanes bearing a syn-N-acyl group, t-BuOK most likely coordinated with both a syn-N-acyl and an oxygen of the Dioxetane ring, so that two imide carbonyls in the produced emitter possessed a considerably regulated structure leading to a red-shift in the chemiluminescence. Such coordination of K+ was hardly expected for the case of the Dioxetanes bearing an anti-N-acyl group, for which the strong contact of K+ to an oxidoaryl group presumably caused a blue-shift in chemiluminescence.
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Synthesis of Thermally Stable Acylamino-Substituted Bicyclic Dioxetanes and Their Base-Induced Chemiluminescent Decomposition
The Journal of organic chemistry, 2010Co-Authors: Nobuko Watanabe, Hisako K. Ijuin, Yusuke Sano, Haruna Suzuki, Masatoshi Tanimura, Masakatsu MatsumotoAbstract:Hydroxyaryl-substituted Dioxetanes 2−4 fused with a pyrrolidine ring were selectively synthesized by singlet oxygenation of the corresponding dihydropyrroles 5−7. These N-acylamino-substituted bicyclic Dioxetanes were quite stable thermally, and 2a and 2b were estimated to possess half-lives of 32 and 34 y at 25 °C. When treated with TBAF (tetrabutylammonium fluoride) in DMSO, these Dioxetanes underwent charge-transfer-induced decomposition (CTID) to emit yellow−orange light. The chemiluminescence efficiencies ΦCL for Dioxetanes 2 ranged from 10−6 to 10−2. On the other hand, Dioxetane 4 bearing a 4-(benzothiazol-2-yl)-3-hydroxyphenyl moiety showed chemiluminescent decomposition with high efficiency (ΦCL = 0.15) comparable to its oxy-analogue 26. Prominent characteristics for CTID of the present Dioxetanes were that the N-acylamino-group influenced the color of chemiluminescence as well as the rate of decomposition kCTID, and furthermore an N-acyl substituent could decisively affect the singlet-chemiexcita...
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Synthesis of sulfanyl-, sulfinyl-, and sulfonyl-substituted bicyclic Dioxetanes and their base-induced chemiluminescence.
Journal of Organic Chemistry, 2010Co-Authors: Nobuko Watanabe, Yuusuke Maniwa, Hisako K. Ijuin, Masato Kikuchi, Masakatsu MatsumotoAbstract:The singlet oxygenation of 4-tert-butyl-3,3-dimethyl-5-(3-oxyphenyl)-2,3-dihydrothiophenes 5c−e bearing an acetoxy or methoxy group at the 2-position exclusively gave the corresponding sulfanyl-substituted bicyclic Dioxetanes 2c−e, while that of 5a without 2-substituent mainly gave sulfoxide 11 along with a small amount of Dioxetane 2a. These Dioxetanes were sufficiently stable thermally to permit handling at room temperature. Sulfanyl-substituted Dioxetanes, 2c and 2e, were further oxidized with m-chloroperbenzoic acid to afford the corresponding sulfinyl-substituted Dioxetanes 3c, 3e and sulfonyl-substituted Dioxetanes 4c, 4e. X-ray single crystallographic analysis was performed for 2c and 4e. Base-induced decomposition of the Dioxetanes in DMSO gave light with a maximum wavelength λmaxCL at 554 nm for 2a and 565 nm for 2e in moderate light yields, while sulfinyl-derivative 3e gave weak light with λmaxCL = 795 nm and sulfonyl-derivative 4e gave very weak light with λmaxCL = 848 nm.
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Alkaline metal ion-enhanced chemiluminescence of bicyclic Dioxetanes bearing a hydroxyaryl group with an ‘ even ’ substitution pattern
Tetrahedron Letters, 2009Co-Authors: Masakatsu Matsumoto, Nobuko Watanabe, Fumihiko Kakuno, Aoi Kikkawa, Naoyuki Hoshiya, Hisako K. IjuinAbstract:Bicyclic Dioxetane 5 bearing a 3-hydroxynaphthalen-2-yl group and its analogs 14 and 15 decomposed to give light with efficiencies of only 0.002–0.005% in a tetrabutylammonium fluoride (TBAF)/THF system, which was as expected for Dioxetanes with a so-called ‘ even ’ substitution pattern. However, the chemiluminescence efficiencies ( Φ CL ) markedly increased when these Dioxetanes were decomposed with alkaline metal t- butoxide in THF. This enhancement of Φ CL by alkaline metal ion was most likely due to the highly ordered conformation of an aromatic ring by chelate formation of the metal ion with both an oxido anion and oxygen atom of a tetrahydrofuran ring in an intermediary Dioxetane like 12 . Alkaline metal ion-enhanced chemiluminescence was similarly observed for Dioxetane 6 bearing a 2-hydroxyphenyl group.
Hisako K. Ijuin - One of the best experts on this subject based on the ideXlab platform.
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organic superbase induced chemiluminescent decomposition of a hydroxyaryl substituted Dioxetane unique effect of a bifunctional guanidine base on the chemiluminescence profile of a bicyclic Dioxetane bearing a 4 benzoxazol 2 yl 3 5 dihydroxyphenyl mo
Tetrahedron Letters, 2018Co-Authors: Nobuko Watanabe, Hisako K. Ijuin, Ayu Wakatsuki, Yoshio Kabe, Masakatsu MatsumotoAbstract:Abstract Organic superbases represented by TBD (1,5,7-triazabicyclo[4.4.0]dec-5-ene) effectively induced the decomposition of hydroxyaryl-substituted Dioxetanes in acetonitrile to give bright light. The color of the chemiluminescence from a Dioxetane bearing a 4-(benzoxazol-2-yl)-3,5-dihydroxyphenyl moiety varied depending on the base used. In addition to this change in the color of emission, TBD increased the chemiluminescence efficiency 2- to 5-fold compared to the results with other base systems and accelerated decomposition of the Dioxetane. These unique effects of TBD may be due to its “bifunctional” character, which is different from those of other organic superbases. Chemiluminescent decomposition of the Dioxetane was effectively induced by superbases even in apolar p-xylene.
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N -Acyl group-directed color modulation in the t -BuOK-mediated chemiluminescent decomposition of hydroxyaryl-substituted Dioxetanes fused with a pyrrolidine ring
Tetrahedron Letters, 2012Co-Authors: Nobuko Watanabe, Hisako K. Ijuin, Haruna Suzuki, Kairi Matsumoto, Teruhiko Tanaka, Masakatsu MatsumotoAbstract:Abstract Bicyclic Dioxetanes, 1-(hydroxyaryl)-2-aza-6,7-dioxabicyclo[3.2.0]heptanes, bearing a syn-N-acyl or anti-N-acyl group underwent TBAF (tetrabutylammonium fluoride)-induced decomposition in DMSO or THF accompanied by the emission of bright light, the maximum wavelengths ( λ max CL ) of which were similar to each other. On the other hand, upon treatment with t-BuOK in THF, the Dioxetanes bearing a syn-N-acyl group emitted light that showed a dramatic red-shift compared to that in a TBAF/THF system, while the Dioxetanes bearing an anti-N-acyl group showed light with a blue-shift. For oxidoaryl-substituted Dioxetanes bearing a syn-N-acyl group, t-BuOK most likely coordinated with both a syn-N-acyl and an oxygen of the Dioxetane ring, so that two imide carbonyls in the produced emitter possessed a considerably regulated structure leading to a red-shift in the chemiluminescence. Such coordination of K+ was hardly expected for the case of the Dioxetanes bearing an anti-N-acyl group, for which the strong contact of K+ to an oxidoaryl group presumably caused a blue-shift in chemiluminescence.
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Synthesis of Thermally Stable Acylamino-Substituted Bicyclic Dioxetanes and Their Base-Induced Chemiluminescent Decomposition
The Journal of organic chemistry, 2010Co-Authors: Nobuko Watanabe, Hisako K. Ijuin, Yusuke Sano, Haruna Suzuki, Masatoshi Tanimura, Masakatsu MatsumotoAbstract:Hydroxyaryl-substituted Dioxetanes 2−4 fused with a pyrrolidine ring were selectively synthesized by singlet oxygenation of the corresponding dihydropyrroles 5−7. These N-acylamino-substituted bicyclic Dioxetanes were quite stable thermally, and 2a and 2b were estimated to possess half-lives of 32 and 34 y at 25 °C. When treated with TBAF (tetrabutylammonium fluoride) in DMSO, these Dioxetanes underwent charge-transfer-induced decomposition (CTID) to emit yellow−orange light. The chemiluminescence efficiencies ΦCL for Dioxetanes 2 ranged from 10−6 to 10−2. On the other hand, Dioxetane 4 bearing a 4-(benzothiazol-2-yl)-3-hydroxyphenyl moiety showed chemiluminescent decomposition with high efficiency (ΦCL = 0.15) comparable to its oxy-analogue 26. Prominent characteristics for CTID of the present Dioxetanes were that the N-acylamino-group influenced the color of chemiluminescence as well as the rate of decomposition kCTID, and furthermore an N-acyl substituent could decisively affect the singlet-chemiexcita...
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Synthesis of sulfanyl-, sulfinyl-, and sulfonyl-substituted bicyclic Dioxetanes and their base-induced chemiluminescence.
Journal of Organic Chemistry, 2010Co-Authors: Nobuko Watanabe, Yuusuke Maniwa, Hisako K. Ijuin, Masato Kikuchi, Masakatsu MatsumotoAbstract:The singlet oxygenation of 4-tert-butyl-3,3-dimethyl-5-(3-oxyphenyl)-2,3-dihydrothiophenes 5c−e bearing an acetoxy or methoxy group at the 2-position exclusively gave the corresponding sulfanyl-substituted bicyclic Dioxetanes 2c−e, while that of 5a without 2-substituent mainly gave sulfoxide 11 along with a small amount of Dioxetane 2a. These Dioxetanes were sufficiently stable thermally to permit handling at room temperature. Sulfanyl-substituted Dioxetanes, 2c and 2e, were further oxidized with m-chloroperbenzoic acid to afford the corresponding sulfinyl-substituted Dioxetanes 3c, 3e and sulfonyl-substituted Dioxetanes 4c, 4e. X-ray single crystallographic analysis was performed for 2c and 4e. Base-induced decomposition of the Dioxetanes in DMSO gave light with a maximum wavelength λmaxCL at 554 nm for 2a and 565 nm for 2e in moderate light yields, while sulfinyl-derivative 3e gave weak light with λmaxCL = 795 nm and sulfonyl-derivative 4e gave very weak light with λmaxCL = 848 nm.
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Alkaline metal ion-enhanced chemiluminescence of bicyclic Dioxetanes bearing a hydroxyaryl group with an ‘ even ’ substitution pattern
Tetrahedron Letters, 2009Co-Authors: Masakatsu Matsumoto, Nobuko Watanabe, Fumihiko Kakuno, Aoi Kikkawa, Naoyuki Hoshiya, Hisako K. IjuinAbstract:Bicyclic Dioxetane 5 bearing a 3-hydroxynaphthalen-2-yl group and its analogs 14 and 15 decomposed to give light with efficiencies of only 0.002–0.005% in a tetrabutylammonium fluoride (TBAF)/THF system, which was as expected for Dioxetanes with a so-called ‘ even ’ substitution pattern. However, the chemiluminescence efficiencies ( Φ CL ) markedly increased when these Dioxetanes were decomposed with alkaline metal t- butoxide in THF. This enhancement of Φ CL by alkaline metal ion was most likely due to the highly ordered conformation of an aromatic ring by chelate formation of the metal ion with both an oxido anion and oxygen atom of a tetrahydrofuran ring in an intermediary Dioxetane like 12 . Alkaline metal ion-enhanced chemiluminescence was similarly observed for Dioxetane 6 bearing a 2-hydroxyphenyl group.
J Cadet - One of the best experts on this subject based on the ideXlab platform.
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formation of 7 8 dihydro 8 oxoguanine in the 1 2 Dioxetane induced oxidation of calf thymus dna evidence for photosensitized dna damage by thermally generated triplet ketones in the dark
Photochemistry and Photobiology, 1995Co-Authors: Waldemar Adam, Chantu R Sahamoller, Andre Schonberger, M Berger, J CadetAbstract:— Isolated calf thymus DNA was treated with the 1,2-Dioxetanes 3-acetoxymethyl-3,4,4-tri-methyl-1,2-Dioxetane, 2,3-dimethylbenzofuran Dioxetane, 3-hydroxymethyl-3,4,4-trimethyl-1,2-dioxeta-ne (HTMD), 3,3,4,4-tetramethyl-1,2-Dioxetane and 3,4,4-trimethyl-1,2-Dioxetane (TrMD), which on thermal decomposition generate triplet-excited carbonyl products. To monitor quantitatively the formation of the mutagenic oxidation product 7,8-dihydro-8-oxoguanine (8-oxoGua), a sensitive and selective HPLC electrochemical assay was used after acidic hydrolysis (HF/pyridine) of the Dioxetane-treated DNA. High yields of 8-oxoGua (up to ca 4% of the available guanine) were obtained for HTMD and TrMD. Both were investigated in detail with respect to effects of concentration, time and temperature. The oxidative reactivity of 1,2-Dioxetanes was compared with several type I (benzophenone and riboflavin) and type II (methylene blue and rose bengal) photooxidants and disodium 1,4-etheno-2,3-ben-zodioxin-1,4-dipropionate as a chemical source of singlet oxygen. The persistence of 8-oxoGua towards oxidation by HTMD was examined in the reaction with 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-oxodGuo) and with oxidized DNA. It was shown that, indeed, 8-oxoGua is consumed in the oxidized DNA on prolonged exposure to an excess of HTMD. The reaction of 8-oxodGuo with HTMD afforded the two 4R* and 4S* diastereomers of 9-(2-deoxy-s-D-erythropentofuranosyl)-4,8-dihydro-4-hydroxy-8-oxoguanine as main oxidation products. Trapping experiments with teft-butanol confirmed that hydroxyl radicals are not involved, whereas the use of the triplet quenchers sodium 9,10-dibromo-anthra-cene-2-sulfonate and 2,3-diazabicyclo[2.2.1]hept-2-ene established that triplet-excited states are mainly responsible for the observed DNA oxidation through type I action (electron transfer chemistry). The role of singlet oxygen was tested by means of deuterium isotope effects in D2O versus H2O, but no definitive conclusion could be reached in regard to the involvement of 102 in these oxidations. The present results reveal that 1,2-Dioxetanes are efficient DNA oxidants and excellent tools to study photooxidation reactions of DNA in the dark.
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FORMATION OF 7,8-DIHYDRO-8-OXOGUANINE IN THE 1,2-Dioxetane-INDUCED OXIDATION OF CALF THYMUS DNA : EVIDENCE FOR PHOTOSENSITIZED DNA DAMAGE BY THERMALLY GENERATED TRIPLET KETONES IN THE DARK
Photochemistry and photobiology, 1995Co-Authors: Waldemar Adam, Chantu R. Saha-möller, Andre Schonberger, M Berger, J CadetAbstract:Isolated calf thymus DNA was treated with the 1,2-Dioxetanes 3-acetoxymethyl-3,4,4-tri-methyl-1,2-Dioxetane, 2,3-dimethylbenzofuran Dioxetane, 3-hydroxymethyl-3,4,4-trimethyl-1,2-Dioxetane (HTMD), 3,3,4,4-tetramethyl-1,2-Dioxetane and 3,4,4-trimethyl-1,2-Dioxetane (TrMD), which on thermal decomposition generate triplet-excited carbonyl products. To monitor quantitatively the formation of the mutagenic oxidation product 7,8-dihydro-8-oxoguanine (8-oxoGua), a sensitive and selective HPLC electrochemical assay was used after acidic hydrolysis (HF/pyridine) of the Dioxetane-treated DNA. High yields of 8-oxoGua (up to ca 4% of the available guanine) were obtained for HTMD and TrMD. Both were investigated in detail with respect to effects of concentration, time and temperature. The oxidative reactivity of 1,2-Dioxetanes was compared with several type I (benzophenone and riboflavin) and type II (methylene blue and rose bengal) photooxidants and disodium 1,4-etheno-2,3-benzodioxin-1,4-dipropionate as a chemical source of singlet oxygen. The persistence of 8-oxoGua towards oxidation by HTMD was examined in the reaction with 7,8-dihydro-8-oxo-2'-deoxyguanosine (8-oxodGuo) and with oxidized DNA. It was shown that, indeed, 8-oxoGua is consumed in the oxidized DNA on prolonged exposure to an excess of HTMD. The reaction of 8-oxodGuo with HTMD afforded the two 4R* and 4S* diastereomers of 9-(2-deoxy-beta-D-erythropentofuranosyl)-4, 8-dihydro-4-hydroxy-8-oxoguanine as main oxidation products. Trapping experiments with tert-butanol confirmed that hydroxyl radicals are not involved, whereas the use of the triplet quenchers sodium 9,10-dibromo-anthracene-2-sulfonate and 2,3-diazabicyclo[2.2.1]hept-2-ene established that triplet-excited states are mainly responsible for the observed DNA oxidation through type I action (electron transfer chemistry). The role of singlet oxygen was tested by means of deuterium isotope effects in D2O versus H2O, but no definitive conclusion could be reached in regard to the involvement of 1O2 in these oxidations.(ABSTRACT TRUNCATED AT 250 WORDS)