- Rapid Iron(III)?Fluoride-Mediated Hydrogen Atom Transfer
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We anticipate high-valent metal–fluoride species will be highly effective hydrogen atom transfer (HAT) oxidants because of the magnitude of the H?F bond (in the product) that drives HAT oxidation. We prepared a dimeric FeIII(F)?F?FeIII(F) complex (1) by reacting [FeII(NCCH3)2(TPA)](ClO4)2 (TPA=tris(2-pyridylmethyl)amine) with difluoro(phenyl)-λ3-iodane (difluoroiodobenzene). 1 was a sluggish oxidant, however, it was readily activated by reaction with Lewis or Br?nsted acids to yield a monomeric [FeIII(TPA)(F)(X)]+ complex (2) where X=F/OTf. 1 and 2 were characterized using NMR, EPR, UV/Vis, and FT-IR spectroscopies and mass spectrometry. 2 was a remarkably reactive FeIII reagent for oxidative C?H activation, demonstrating reaction rates for hydrocarbon HAT comparable to the most reactive FeIII and FeIV oxidants.
- Doyle, Lorna M.,Gericke, Robert,McDonald, Aidan R.,Panda, Chakadola
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supporting information
p. 26281 - 26286
(2021/11/12)
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- Locking the phenyl rings of tetraphenylethene step by step: Understanding the mechanism of aggregation-induced emission
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Stepwise locking of phenyl rings of tetraphenylethene increases the emission efficiency of luminogen solutions gradually, thus verifying the restriction of intramolecular rotation (RIR) mechanism of the aggregation induced emission phenomenon. The emissio
- Shi, Junqing,Chang, Ning,Li, Cuihong,Luo, Xiaoliang,Liu, Zhengping,Bo, Zhishan,Dong, Yong Qiang,Mei, Ju,Tang, Ben Zhong,Deng, Chunmei
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supporting information
p. 10675 - 10677,3
(2020/09/02)
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- Stereoselective synthesis of olefins by a reductive coupling reaction
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Ketones and aldehydes are converted to symmetrical and (E)-olefins (1-15) by reaction with 2,4-bis(phenyl)-1,3-diselenadiphosphetane-2,4-diselenide (PhPSe2)2, Woollins' reagent, in refluxing toluene; use of diketones was demonstrated by the reaction of PhC(O)CH2C(O)Ph which gives 1,2,4,5-tetraphenylbenzene (16) in 83% yield. The Royal Society of Chemistry 2007.
- Hua, Guoxiong,Li, Yang,Slawin, Alexandra M. Z.,Woollins, J. Derek
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p. 1477 - 1480
(2007/10/03)
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- Bimolecular formation of radicals by hydrogen transfer, 12: Transfer hydrogenation of p-substituted α-methylstyrenes and of 9-methylenefluorene as a criterion of mechanism
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The uncatalyzed transfer hydrogenation of substituted α-methylstyrenes with 9,10-dihydroanthracene (DHA), xanthene (XAN), or 9,10-dihydroacridine (DHAC) was studied mechanistically. The three hydrogen donors react at very similar rates and with similar activation parameters and with little discrimination between the various substituted styrenes. The kinetic isotope effects are also similar and the solvent effect is small. A hydrogen atom transfer mechanism (retrodisproportionation) is, therefore, preferred to a hydride transfer mechanism. This is supported by the very similar reactivity of the hydrogen transfer reaction of DHA and XAN with 9-methylenefluorene. The product yields in all reactions investigated in this project were >90%. VCH Verlagsgesellschaft mbH, 1997.
- Friebolin, Heike,Roers, Rolf,Ebenhoch, Jochen,Gerst, Matthias,Ruechardt, Christoph
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p. 385 - 389
(2007/10/03)
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- Novel reductive couplinog-rearrangement of carbonyl compounds with metal/Lewis acid under irradiation of ultrasonic wave
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Novel reductive coupling-rearrangement of carbonyl compounds such as benzophenones with Al or Zn/ AlCl3 in CH3CN under irradiation of ultrasonic wave gave benzopinacolones via epoxides in good yields.
- Sato, Ryu,Nagaoka, Takeshi,Saito, Minoru
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p. 4165 - 4168
(2007/10/02)
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- Chemical and Physical Properties of 9-Xanthylidene: A Ground-State Singlet Aromatic Carbene
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Irradiation of 9-diazoxanthene (DAX) leads to loss of N2 and formation of 9-xanthylidene (XA).This carbene was detected at low temperature in a frozen glass and by laser transient absorption spectroscopy.It reacts rapidly with alcohols to form ethers and with styrenes to give cyclopropanes stereospecifically.At room temperature, XA does not react significantly with hydrocarbons, but at elevated temperature, an insertion reaction characteristic of a singlet carbene is observed.Rate constants for these and other reactions are reperted.The data show that XA is a ground-state singlet carbene with a triplet state at least 4 kcal/mol above the singlet.This finding is incorporated into a general explanation of aromatic carbene reactivity.
- Lapin, Stephen C.,Schuster, Gary B.
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p. 4243 - 4248
(2007/10/02)
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- New Olefin and Oxiran Syntheses from Carbonyl Compounds, and Diethyl Sodiophosphonate Anions and 1-Aminophosphonate Amino-anions
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Reaction of aromatic aldehydes, and phthalic and thiophthalic anhydrides, with diethyl sodiophosphonate (1) gives the trans-stilbenes (3), 3,3'-biphthalidylidene (30), and 3,3'-bis-(2-thiophthalidylidene) (33).Similar treatment of fluorenone (8) and xanthone (17) with (1) leads to 9,9'-bis(fluororenylidene) (9) and 9,10-dihydro-9-oxophenanthrene-10-spiro-9'-fluorene (10), and to 9,9'-bixanthenylidene (18) and 9,9'-bixanthenyl (19), respectively, but the reaction using anthrone (11) as a carbonyl reagent yields only anthraquinone (12) and anthracene (13).Similar treatment using N-methylisatoic anhydride (34) and N-methylisatin (36) produces NN'-dimethylisoindigo (35).Reaction of benzaldehyde and p-chlorobenzaldehyde with diethyl 1--cyclohexylphosphonate (40) gives mainly corresponding mixtures of trans- (41a,b) and cis-stilbene epoxides (42a,b), while similar treatment of p-nitrobenzaldehyde with (40) produces 4,4'-dinitrostilbene (3e).Reaction of (8) with (40), as well as with (1), gives (9) and (10).The mechanism of formation of these products is discussed.
- Minami, Toru,Matsuzaki, Narihide,Ohshiro, Yoshiki,Agawa, Toshio
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p. 1731 - 1738
(2007/10/02)
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