Phosphadioxirane: A Peroxide from an Ortho-Substituted Arylphosphine and Singlet Dioxygen

Ho, David; Gao, Rong; Celaje, Jeff Joseph A.; Chung, Ha-Yong; Selke, Matthias

doi:10.1126/science.1089145

Cited by 69 publications

(70 citation statements)

References 11 publications

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“…Ph 3 PO 2 reacts with the large excess of Ph 3 P to give Ph 3 P=O via O-O bond cleavage. 57 In contrast to the case of Acr þ -Mes in Scheme 1, the AcrH þ -catalyzed photooxygenation of Ph 3 P with O 2 proceeds via electron transfer from Ph 3 P to tooxygenation are always lower compared to that of Acr þ -Mes (Fig. 1a), This is ascribed to the absence of the radical coupling reaction between Ph 3 P þ and O 2 À (Scheme 2).…”

Section: Resultsmentioning

confidence: 85%

Photocatalytic Electron-Transfer Oxidation of Triphenylphosphine and Benzylamine with Molecular Oxygen via Formation of Radical Cations and Superoxide Ion

Ohkubo¹,

Nanjo²,

Fukuzumi³

2006

Bulletin of the Chemical Society of Japan

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Photooxygenation of triphenylphosphine (Ph3P) to triphenylphosphine oxide (Ph3P=O) with molecular oxygen (O2) occurs under photoirradiation of 9-mesityl-10-methylacridinium perchlorate ([Acr+–Mes]ClO4−) which acts as an efficient electron-transfer photocatalyst. Photooxidation of benzylamine (PhCH2NH2) with O2 also occurs efficiently under photoirradiation of Acr+–Mes to yield PhCH2N=CHPh and hydrogen peroxide (H2O2). Each photocatalytic reaction is initiated by intramolecular photoinduced electron transfer from the Mes moiety to the singlet excited state of the Acr+ moiety to produce the electron-transfer state (Acr•–Mes•+). The Mes•+ moiety oxidizes Ph3P and PhCH2NH2 to produce the radical cations (Ph3P•+ and PhCH2NH2•+, respectively), whereas the Acr• moiety reduces O2 to O2•−. The produced Ph3P•+ binds with O2•− as well as O2, leading to the oxygenated product (Ph3P=O). On the other hand, proton transfer from PhCH2NH2•+ to O2•− occurs, followed by hydrogen transfer, leading to the dehydrogenated dimer product, PhCH2N=CHPh. In each case, the radical intermediates were detected by laser flash photolysis and ESR measurements to clarify the photocatalytic mechanism.

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Section: Resultsmentioning

confidence: 85%

Photocatalytic Electron-Transfer Oxidation of Triphenylphosphine and Benzylamine with Molecular Oxygen via Formation of Radical Cations and Superoxide Ion

Ohkubo¹,

Nanjo²,

Fukuzumi³

2006

Bulletin of the Chemical Society of Japan

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“…The three-membered ring peroxides with the form R 3 PO 2 , where the R group represents alkyl or aryl substituents, were reported to act as intermediates in reactions of singlet oxygen with organic phosphines in solutions and in the gaseous phase at room temperature and higher temperatures [1][2][3][4][30][31][32]. There has been much recent interest to such 'exotic peroxides' -to quote from the title of a recent review by Sawwan and Greer [33].…”

Section: Resultsmentioning

confidence: 99%

“…Recently, it has been reported that singlet molecular oxygen (generated photochemically with intermediacy of a photosensitizer) reacts with phosphines (1) in solutions at room temperature. In such reactions, the corresponding phosphine oxides (2) are generated as dominating products, whereas phosphinates (3) are produced only in very small amounts [1][2][3][4].…”

Section: Introductionmentioning

confidence: 99%

Photoinduced oxidation of triphenylphosphine isolated in a low-temperature oxygen matrix

Reva

Lapiński

Nowak

2008

Chemical Physics Letters

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a b s t r a c tPhotooxidation reactions of triphenylphosphine (Ph 3 P) monomers isolated in matrices of solid oxygen at 10 K were characterized by means of infrared spectroscopy. Upon UV (k > 280 nm) irradiation of O 2 matrices, ca. 90% of Ph 3 P was converted to triphenylphosphine oxide (Ph 3 P@O), with concomitant formation of ozone. In the competing photoreaction, ca. 10% of Ph 3 P was converted to diphenyl-phenyl-phosphinate, Ph 2 (PhÀOÀ)P@O. The interpretation was assisted by theoretical [DFT(B3LYP)/6-31G(d, p)] calculations of vibrational spectra, as well as by comparison with the experimental vibrational data from separate experiments in which monomeric Ph 3 P and Ph 3 P@O were isolated in argon and oxygen matrices at 10 K.

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“…However, due to the severe steric hindrance caused by the bulkiness of the metal-containing compound, the dimer route is probably not feasible for a compound with a bulky substituent, such as 8 a. [20] Therefore, the 8 a!8 a' conversion is less likely. However, our experimental observation that 8 b is an efficient ligand in the Pd-catalyzed Heck reaction between bromobenzene and styrene suggests that the transformation 8 b!8 b' indeed occurs to some extent in solution.…”

Section: Wwwchemeurjorgmentioning

confidence: 99%

Experimental and DFT Study of the Tautomeric Behavior of Cobalt‐Containing Secondary Phosphine Oxides

Wei

Huang

et al. 2007

Chemistry A European J

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New cobalt-containing secondary phosphine oxides [(mu-PPh(2)CH(2)PPh(2))Co(2)(CO)(4){mu,eta-PhC[triple chemical bond]CP(==O)(H)(R)}] (8 a: R=tBu; 8 b: R=Ph) were prepared by reaction of secondary phosphine oxides PhC[triple chemical bond]CP- (==O)(H)(R) (6 a: R=tBu; 6 b: R=Ph) with dppm-bridged dicobalt complex [(mu-PPh(2)CH(2)PPh(2))Co(2)(CO)(6)] (2). The molecular structures of 8 a and 8 b were determined by single-crystal X-ray diffraction. Although palladium-catalyzed Heck reactions employing 8 b as ligand gave satisfying results, 8 a performed poorly in the same reaction. Judging from these results, a tautomeric equilibrium between 8 b and its isomeric form [(mu-PPh(2)CH(2)PPh(2))Co(2)(CO)(4){mu,eta-PhC[triple chemical bond]CP(OH)(Ph)}] 8 b' indeed takes place, but it is unlikely between 8 a and [(mu-PPh(2)CH(2)PPh(2))Co(2)(CO)(4){mu,eta-PhC[triple chemical bond]CP(OH)(tBu)}] (8 a'). The DFT studies demonstrated that reasonable activation energies for the tautomeric conversions can be achieved only via a bimolecular pathway. Since a tBu group is much larger than a Ph group, the conversion is presumably only feasible in the case of 8 bright harpoon over left harpoon8 b', but not in the case of 8 aright harpoon over left harpoon8 a'. Another cobalt-containing phosphine, namely, [(mu-PPh(2)CH(2)PPh(2))Co(2)(CO)(4){mu,eta-PhC[triple chemical bond]CP(NEt(2))(tBu)}] (7 a), and its oxidation product [(mu-PPh(2)CH(2)PPh(2))Co(2)(CO)(4){mu,eta-PhC[triple chemical bond]CP(==O)(NEt(2))(tBu)}] 7 a' were prepared from the reaction of PhC[triple chemical bond]CP(NEt(2))(tBu) (5 a) with 2. The molecular structures of 7 a and 7 a' were determined by single-crystal X-ray diffraction. The phosphorus atom is surrounded by substituents in a tetrahedral environment. A P--N single bond (1.676(3) A) is observed in the molecular structure of 7 a. Heck reactions employing 7 a/Pd(OAc)(2) as catalyst system exhibited efficiency comparable to that of 8 a/Pd(OAc)(2).

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Phosphadioxirane: A Peroxide from an Ortho-Substituted Arylphosphine and Singlet Dioxygen

Cited by 69 publications

References 11 publications

Photocatalytic Electron-Transfer Oxidation of Triphenylphosphine and Benzylamine with Molecular Oxygen via Formation of Radical Cations and Superoxide Ion

Photocatalytic Electron-Transfer Oxidation of Triphenylphosphine and Benzylamine with Molecular Oxygen via Formation of Radical Cations and Superoxide Ion

Photoinduced oxidation of triphenylphosphine isolated in a low-temperature oxygen matrix

Experimental and DFT Study of the Tautomeric Behavior of Cobalt‐Containing Secondary Phosphine Oxides

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