1
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Boice GN, Garakyaraghi S, Patrick BO, Sanz CA, Castellano FN, Hicks RG. Diastereomerically Differentiated Excited State Behavior in Ruthenium(II) Hexafluoroacetylacetonate Complexes of Diphenyl Thioindigo Diimine. Inorg Chem 2018; 57:1386-1397. [DOI: 10.1021/acs.inorgchem.7b02803] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Geneviève N. Boice
- Department of Chemistry, University of Victoria, PO Box 3065 STN CSC, Victoria, British
Columbia V8W 3V6, Canada
| | - Sofia Garakyaraghi
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Brian O. Patrick
- Crystallography Laboratory, Department
of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada
| | - Corey A. Sanz
- Department of Chemistry, University of Victoria, PO Box 3065 STN CSC, Victoria, British
Columbia V8W 3V6, Canada
| | - Felix N. Castellano
- Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695-8204, United States
| | - Robin G. Hicks
- Department of Chemistry, University of Victoria, PO Box 3065 STN CSC, Victoria, British
Columbia V8W 3V6, Canada
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2
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Theoretical study of the structure and thermochemical proprieties of adducts of the gas phase reaction of NH 2 CO with HCO possibly formed under atmospheric conditions on the prebiotic Earth. COMPUT THEOR CHEM 2017. [DOI: 10.1016/j.comptc.2017.08.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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3
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Ranaweera RAAU, Weragoda GK, Bain J, Watanabe S, Abe M, Gudmundsdottir AD. Photolysis of acetophenone derivatives with α-cyclopropyl substituents. J PHYS ORG CHEM 2014. [DOI: 10.1002/poc.3389] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | | | - John Bain
- Department of Chemistry; University of Cincinnati; Cincinnati OH 45221-0172 USA
| | - Shinji Watanabe
- Department of Chemistry, Graduate School of Science; Hiroshima University; 1-3-1 Kagamiyama Higashi-Hiroshima Hiroshima 739 -8526 Japan
| | - Manabu Abe
- Department of Chemistry, Graduate School of Science; Hiroshima University; 1-3-1 Kagamiyama Higashi-Hiroshima Hiroshima 739 -8526 Japan
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4
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Bucher G, Bresolí-Obach R, Brosa C, Flors C, Luis JG, Grillo TA, Nonell S. β-Phenyl quenching of 9-phenylphenalenones: a novel photocyclisation reaction with biological implications. Phys Chem Chem Phys 2014; 16:18813-20. [DOI: 10.1039/c4cp02783c] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
β-Phenyl quenching of 9-phenylphenalenones leads to the reversible formation of naphthoxanthenes and eventually to stable naphthoxanthenyl radicals or naphthoxanthenium cations.
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Affiliation(s)
- Götz Bucher
- WestCHEM
- School of Chemistry
- University of Glasgow
- Glasgow G12 8QQ, UK
| | | | - Carme Brosa
- Institut Químic de Sarrià
- Universitat Ramon Llull
- Barcelona, Spain
| | - Cristina Flors
- Institut Químic de Sarrià
- Universitat Ramon Llull
- Barcelona, Spain
- IMDEA Nanociencia
- E-28049 Madrid, Spain
| | - Javier G. Luis
- Instituto Universitario de Bio-Orgánica “Antonio González”
- La Laguna, Tenerife, Spain
- Departamento de Química Orgánica
- Facultad de Farmacia
- La Laguna, Tenerife, Spain
| | - Teresa A. Grillo
- Instituto Universitario de Bio-Orgánica “Antonio González”
- La Laguna, Tenerife, Spain
- Departamento de Química Orgánica
- Facultad de Farmacia
- La Laguna, Tenerife, Spain
| | - Santi Nonell
- Institut Químic de Sarrià
- Universitat Ramon Llull
- Barcelona, Spain
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5
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Landers B, Berini C, Wang C, Navarro O. (N-Heterocyclic Carbene)-Pd-Catalyzed Anaerobic Oxidation of Secondary Alcohols and Domino Oxidation−Arylation Reactions. J Org Chem 2011; 76:1390-7. [DOI: 10.1021/jo102385u] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Brant Landers
- Department of Chemistry, University of Hawaii at Manoa, 2545 McCarthy Mall, Honolulu, Hawaii 96822, United States
| | - Christophe Berini
- Department of Chemistry, University of Hawaii at Manoa, 2545 McCarthy Mall, Honolulu, Hawaii 96822, United States
| | - Chao Wang
- Department of Chemistry, University of Hawaii at Manoa, 2545 McCarthy Mall, Honolulu, Hawaii 96822, United States
| | - Oscar Navarro
- Department of Chemistry, University of Hawaii at Manoa, 2545 McCarthy Mall, Honolulu, Hawaii 96822, United States
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6
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Ma C, Kwok W, An HY, Guan X, Fu M, Toy P, Phillips D. A Time-Resolved Spectroscopic Study of the Bichromophoric Phototrigger 3′,5′-Dimethoxybenzoin Diethyl Phosphate: Interaction Between the Two Chromophores Determines the Reaction Pathway. Chemistry 2010; 16:5102-18. [DOI: 10.1002/chem.200902891] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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7
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Bucher G. Addition of the Carbonyl Oxygen to the ipso- or ortho-Carbon Atoms of the β-Phenyl Ring Followed by Intersystem Crossing and Rapid Relaxation to the Ground-State Ketones: A Mechanism for β-Phenyl Quenching of the First Triplet Excited States of Derivatives of β-Phenylpropiophenone. J Phys Chem A 2008; 112:5411-7. [DOI: 10.1021/jp711266z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Götz Bucher
- Lehrstuhl für Organische Chemie II, Ruhr-Universität Bochum, Universitätsstr. 150, D-44801 Bochum, Germany
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8
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Jones PB, Brinson RG, Sarma SJ, Elkazaz S. Observation of heavy atom effects in the development of water soluble caged 4-hydroxy-trans-2-nonenal. Org Biomol Chem 2008; 6:4204-11. [DOI: 10.1039/b810954k] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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9
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Abad S, Bosca F, Domingo LR, Gil S, Pischel U, Miranda MA. Triplet Reactivity and Regio-/Stereoselectivity in the Macrocyclization of Diastereomeric Ketoprofen−Quencher Conjugates via Remote Hydrogen Abstractions. J Am Chem Soc 2007; 129:7407-20. [PMID: 17508750 DOI: 10.1021/ja0712827] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Intramolecular excited triplet state interactions in diastereomeric compounds composed of a benzophenone chromophore (ketoprofen) and various hydrogen donor moieties (tetrahydrofuran, isopropylbenzene) have been investigated by laser flash photolysis. The rate constants for hydrogen abstraction by excited triplet benzophenone are in the order of 10(4)-10(5) s(-1), with the highest reactivity for the tetrahydrofuran residue. A remarkable diastereodifferentiation, expressed in the triplet lifetimes of the carbonyl chromophore (e.g., 1.6 versus 2.7 micros), has been found for these compounds. With an alkylaromatic moiety as donor, related effects have been observed, albeit strongly dependent on the length of the spacer. The reactivity trend for the initial hydrogen transfer step is paralleled by the quantum yields of the overall photoreaction. The biradicals, formed via remote hydrogen abstraction, undergo intramolecular recombination to macrocyclic ring systems. The new photoproducts have been isolated and characterized by NMR spectroscopy. The stereochemistry of the macrocycles, which contain up to four asymmetric carbons, has been unambiguously assigned on the basis of single-crystal structures and/or NOE effects. Interestingly, a highly regio- and stereoselective macrocyclization has been found for the ketoprofen-tetrahydrofuran conjugates, where hydrogen abstraction from the less substituted carbon is exclusive; cisoid ring junction is always preferred over the transoid junction. The photoreaction is less regioselective for compounds with an isopropylbenzene residue. The reactivity and selectivity trends have been rationalized by DFT (B3LYP/6-31G*) calculations.
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Affiliation(s)
- Sergio Abad
- Instituto de Tecnología Química, UPV-CSIC, Universidad Politécnica de Valencia, Av. de los Naranjos s/n, E-46022 Valencia, Spain
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10
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Samanta S, Mishra BK, Pace TCS, Sathyamurthy N, Bohne C, Moorthy JN. β-Phenyl Quenching of Triplet Excited Ketones: How Critical Is the Geometry for Deactivation? J Org Chem 2006; 71:4453-9. [PMID: 16749774 DOI: 10.1021/jo060200e] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The phenomenon of beta-phenyl quenching has been examined by laser-flash photolysis in a series of alpha- and/or beta-substituted ketones 4-8 with similar excited-state characteristics. It is found that alpha-substitution markedly increases the triplet lifetimes in contrast to beta-substitution. The force field calculations for the various staggered conformers of ketones 4-6 and 8-syn show that the lowest-energy conformation in all these ketones has the carbonyl group and the beta-phenyl ring gauche to each other. Despite this geometrical requirement, the longer lifetimes observed are interpreted as being due to the influence of the alpha-substituent on the rotational freedom of the planar benzoyl moiety as a whole. The experimental results are suggestive of the attainment of what appears to be a critical geometry for quenching. This scenario may be likened to Norrish type II reactions, where the alpha-substituent has long been known to suppress the elimination pathway and promote Yang cyclization. In addition, we have shown that the diastereomers of alpha,beta-disubstituted ketones exhibit distinct lifetimes.
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Affiliation(s)
- Subhas Samanta
- Department of Chemistry, Indian Institute of Technology, Kanpur 208016, India
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11
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Singhal N, Koner AL, Mal P, Venugopalan P, Nau WM, Moorthy JN. Diastereomer-Differentiating Photochemistry of β-Arylbutyrophenones: Yang Cyclization versus Type II Elimination. J Am Chem Soc 2005; 127:14375-82. [PMID: 16218632 DOI: 10.1021/ja0523643] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The diastereomers of ketones 2 and 3 are shown to exhibit distinct photochemical reactivities due to conformational preferences; while the anti isomers of 2 and 3 undergo efficient Yang cyclization in 75-90% yields with a remarkable diastereoselectivity (> 90%), the syn isomers predominantly undergo Norrish Type II elimination. The differences in the product profiles of the diastereomers are consistent with a mechanistic picture involving the formation of precursor diastereomeric triplet 1,4-biradicals in which the substituents at alpha and beta-positions stabilize the cisoid (cyclization) or transoid (elimination) geometry. The fact that such a diastereomeric relationship does indeed ensue at the triplet-excited-state itself is demonstrated via the nanosecond laser-flash photolysis of model ketones 1. The diastereomeric discrimination in the product profiles observed for ketones 2 and 3 as well as in the triplet lifetimes observed for ketones 1 can both be mechanistically traced back to different conformational preferences of the ground-state diastereomeric ketones and the intermediary 1,4-biradicals. Additionally, it emerges from the present study that the syn and anti diastereomers of ketones 2 and 3 represent two extremes of a broad range of widely examined butyrophenones, which lead to varying degrees of Yang photocyclization depending on the alkyl substitution pattern.
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Affiliation(s)
- Nidhi Singhal
- Department of Chemistry, Indian Institute of Technology, Kanpur 208 016, India
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12
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Lhiaubet-Vallet V, Encinas S, Miranda MA. Excited State Enantiodifferentiating Interactions between a Chiral Benzophenone Derivative and Nucleosides. J Am Chem Soc 2005; 127:12774-5. [PMID: 16159251 DOI: 10.1021/ja053518h] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Time-resolved measurements using nanosecond laser flash photolysis have revealed significant enantiodifferentiation in the interaction between ketoprofen (a chiral benzophenone derivative) and two relevant nucleosides, namely, thymidine and 2'-deoxyguanosine. In both cases, the highest quenching rate constants have been observed for (R)-ketoprofen, the enantiomer with lower pharmacological activity. Photoproduct studies performed in the case of thymidine suggest that the enantiodifferentiating process corresponds to a Paterno-Büchi reaction, leading to the formation of oxetanes. With 2'-deoxyguanosine, the quenching is associated with an electron-transfer process monitored through the generation of a ketyl radical.
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Affiliation(s)
- Virginie Lhiaubet-Vallet
- Instituto de Tecnología Química UPV-CSIC, Universidad Politécnica de Valencia, Avda de Los Naranjos s/n, 46022 Valencia, Spain
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13
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Encinas S, Climent MJ, Belmadoui N, Miranda MA. Stereo-differentiation in the excited state behaviour of naphthalene-thymine dyads. Chem Commun (Camb) 2005:2572-4. [PMID: 15900330 DOI: 10.1039/b419136f] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Using two diastereomeric dyads containing naphthalene and thymine units, significant chiral discrimination has been found in the photophysical processes involving the naphthalene excited states: singlet deactivation by hydrogen bonding molecules, singlet-singlet energy transfer from thymine and triplet decay.
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Affiliation(s)
- Susana Encinas
- Instituto de Tecnología Química UPV-CSIC/Departamento de Química, Universidad Politécnica de Valencia, Avda de los Naranjos s/n, 46022 Valencia, Spain
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14
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Lhiaubet-Vallet V, Sarabia Z, Boscá F, Miranda MA. Human Serum Albumin-Mediated Stereodifferentiation in the Triplet State Behavior of (S)- and (R)-Carprofen. J Am Chem Soc 2004; 126:9538-9. [PMID: 15291547 DOI: 10.1021/ja048518g] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
A remarkable stereodifferentiation has been observed in the interaction between the excited triplet state of carprofen (CP) and human serum albumin (HSA). Time-resolved measurements using laser flash photolysis reveal the presence of two components with different lifetimes in triplet decay. This is explained by complexation of CP to the two possible HSA binding sites. The shorter-lived components are ascribed to the CP/HSA complexes in site I, where stereodifferentiation is more important (tauR/tauS ca. 4). This is correlated with formation of a dehalogenated photoproduct upon steady-state photolysis.
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Affiliation(s)
- Virginie Lhiaubet-Vallet
- Instituto de Tecnología Química UPV-CSIC, Universidad Politécnica de Valencia, Avenida de los Naranjos s/n, 46022 Valencia, Spain
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15
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Consuelo Jimenez M, Stiriba SE, Tormos R, Perez-Prieto J, Miranda MA. Stereoselectivity in the triplet decay of chiral benzophenone–naphthalene bichromophoric systems. Photochem Photobiol Sci 2004; 3:36-8. [PMID: 14743277 DOI: 10.1039/b308195h] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Chiral recognition in the intramolecular induced quenching of the methoxynaphthalene triplet by benzophenone has been observed by using diastereomeric bichromophores
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Affiliation(s)
- M Consuelo Jimenez
- Departamento de Química Organica/Instituto de Ciencia Molecular, Facultad de Farmacia, Universidad de Valencia, Vicent Andres Estelles s/n, Burjassot, 46100 Valencia, Spain
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16
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Norrish Type II photoreactivity of β-anisylalkanophenones and solvent effects on stereoselective Yang cyclization. Tetrahedron Lett 2003. [DOI: 10.1016/s0040-4039(03)00318-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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17
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Engineering reactions in crystals: suppression of photodecarbonylation by intramolecular β-phenyl quenching. Tetrahedron Lett 2001. [DOI: 10.1016/s0040-4039(01)01922-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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18
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Islam SDM, Yoshikawa Y, Fujitsuka M, Ito O, Komatsu S, Usui Y. Photoreduction of methylviologen using methylacridine orange in the presence of triethanolamine in ethanol–water mixtures. J Photochem Photobiol A Chem 2000. [DOI: 10.1016/s1010-6030(00)00266-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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