- Photoorganocatalytic synthesis of lactones: Via a selective C-H activation-alkylation of alcohols
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Selective C-H activation is an area of growing importance in modern organic chemistry. Herein, we report our efforts in combining organocatalysis and photocatalysis for the development of a highly efficient and selective visible-light mediated protocol for the C-H activation and addition of various alcohols to a plethora of Michael acceptors, followed by a cyclization reaction leading to lactones, a repeatedly occurring motif in nature. Utilizing phenylglyoxylic acid as the photocatalyst and common household bulbs as the light source, we describe a versatile α-alkylation/lactonization of alcohols with α,β-unsaturated esters leading to products in excellent yields. The reaction mechanism was extensively studied.
- Kaplaneris, Nikolaos,Bisticha, Aikaterini,Papadopoulos, Giorgos N.,Limnios, Dimitris,Kokotos, Christoforos G.
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supporting information
p. 4451 - 4456
(2017/09/29)
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- Synthesis and characterization of a new hydroxyl functionalized diacidic ionic liquid as catalyst for the preparation of diester plasticizers
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Two new functionalized diacidic ionic liquids (FDAILs) including hydroxyl functionalized diacidic ionic liquid (HFDAIL) and sulfonated diacidic ionic liquid (SFDAIL) were synthesized and characterized by 1HNMR, 13CNMR and FT-IR. The catalytic activities of these FDAILs were examined in esterification reaction of anhydrides with some alcohols to give corresponding dialkyl plasticizers under solvent-free conditions. The results indicate that HFDAIL, as hydroxyl-bearing catalyst, show better catalytic performance. Under the optimum conditions, using HFDAIL, the conversion of phthalic anhydride was high and diester plasticizers were obtained with good to excellent yields in the presence of only 10?mol% of ionic liquid. All the produced diesters could be easily recovered due to their immiscibility with the ionic liquid. Recycling experiments suggests that these ionic liquids can be reused several times without remarkable loss in their catalytic activity.
- Fareghi-Alamdari, Reza,Nadiri Niri, Mehri,Hazarkhani, Hassan
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p. 153 - 160
(2016/12/30)
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- Role of the succinate skeleton in the disorder-order transition of AOT and its analogous molecules: Detection by infrared absorption spectra of the configurations arising from the difference in torsion angles of the succinate skeleton
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The IR spectra in the 13001450 cm-1 region, which reflect the CH and CH2 deformation vibrational modes of the succinate skeleton, have been investigated in detail for sodium dialkylsulfonates (alkyl groups: Ethyl, n-propyl, n-butyl, n-hexyl, n-heptyl, n-octyl, n-decyl, and n-dodecyl) and sodium 1,2-bis(2-ethylhexyl)sulfosuccinate (sodium 1,2-bis(2- ethylhexyloxycarbonyl)ethanesulfonate) (AOT). The results have provided clear evidence that two configurations, arising from the difference in the torsion angles of the succinate skeleton, are preferentially stabilized in aqueous solution as well as in the solid state, depending upon the concentration. Thus, the IR spectra of this region can be used as a powerful tool for elucidation of the mechanism of the disorderorder transition in aggregate systems of AOT or its homologs at the molecular level.
- Okabayashi, Hiro-Fumi,Izawa, Ken-Ichi,Sumiya, Akiko,Eastoe, Julian,O'Connor, Charmian J.
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experimental part
p. 651 - 659
(2010/08/08)
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- Highly chemo- and stereoselective intermolecular coupling of diazoacetates to give cis-olefins by using Grubbs second-generation catalyst
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Highly stereoselective formation of cis-2-ene-1,4-diesters by homo- and heterocoupling of α-diazoacetates in the presence of Grubbs second-generation catalyst is demonstrated. The dual reactivity of the catalyst in alkene metathesis and diazocoupling has been exploited in the synthesis of 12-26-membered macrocyclic dienyl dilactones by one-pot carbene dimerisation/ring-closing metathesis.
- Hodgson, David M.,Angrish, Deepshikha
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p. 3470 - 3479
(2008/02/08)
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- β-Carbonyl substituted glutathione conjugates as inhibitors of O. volvulus GST2
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A series of β-carbonyl substituted glutathione conjugates were prepared and evaluated as inhibitors of OvGST2. Their specificity for the parasite derived protein was assessed through comparison with their inhibition of human πGST. Inhibition of OvGST2 has been demonstrated at low micromolar concentrations for these conjugates and selectivity for OvGST2 over human π-GST of greater than 10-fold has been achieved. (C) 2000 Elsevier Science Ltd. All rights reserved.
- Brophy, Peter M.,Campbell, Alison M.,Van Eldik, Annamaria J.,Teesdale-Spittle, Paul H.,Liebau, Eva,Wang, Meng F.
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p. 979 - 981
(2007/10/03)
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- Raman and IR spectroscopic studies of the interaction between counterion and polar group in self-assembled systems of AOT-homologous 'sodium dialkyl sulfosuccinates'
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Headgroup-counterion interactions have been studied for a homologous series of sodium dialkyl sulfosuccinates (SDAS) with propyl, butyl, hexyl, octyl, decyl, undecyl and dodecyl chains as Aerosol-OT analogues. Raman scattering and IR absorption spectra were recorded and compared with those for dimethyl sulfosuccinate monohydrate, diethyl sulfosuccinate trihydrate and diheptyl sulfosuccinate dihydrate, whose crystal structures are known. The spectral features of the C=O and SO3- stretch modes directly reflect the interaction between the polar group and the Na+ ion and depend strongly upon the environment of hydration. The results may be summarized as follows. For the SDAS monohydrates in the solid state, there exists a strong interaction between the β C=O group and the Na+ ion, as a consequence of coordination of the β C=O to the Na+ ion, resulting in splitting of the C=O stretch modes. In particular, the common Raman (IR) bands observed at 1705- 1707 (1706-1708) and 1730-1732 (1732-1733) cm-1 may be assigned to the β C=O group coordinated to the Na+ counterion and the hydrated α C=O group, respectively. The extent of splitting of these bands is a measure of the strength of this C=O···Na+ interaction. Coordination of the β C=O to the Na+ ion also affects the C=O deformation modes of the O-C=O linkage. An increased hydration number and longer hydrocarbon chains induce a weak interaction between the C=O group and the Na+ ion. The SO3-···Na6+ interaction reflects the SO3- stretch modes, depending upon the extent of hydration. Furthermore, for the SDAS samples in the organic and aqueous microphases, Raman (IR) bands characteristic of the C=O and SO3-1 groups have been used successfully to account for the interaction between the polar group and the Na+ ion.
- Nagasoe, Yasuyuki,Ichiyanagi, Naoki,Okabayashi, Hirofumi,Nave, Sandrine,Eastoe, Julian,O'Connor, Charmian J.
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p. 4395 - 4407
(2007/10/03)
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