- Synthesis, Characterization, and Application of Oxo-Molybdenum(V)-Corrolato Complexes in Epoxidation Reactions
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Sharpless et al. have described, while performing the molybdenum-catalyzed epoxidation reaction of olefins using alkyl hydroperoxides, that the molybdenum-oxo moiety is an active catalytic species. Thus, continuous efforts have been made to synthesize molybdenum-oxo complexes of different ligand environments. While plenty of such works on molybdenum porphyrins are reported in the literature, related molybdenum corroles are very less reported. The synthesis and characterization of two new oxo-molybdenum(V)-corrolato complexes are described herein. Both the complexes have been fully characterized by several spectroscopic techniques in conjunction with single-crystal X-ray diffraction analysis. The efficacy of the oxo-molybdenum(V)-corrolato complexes for the catalytic epoxidation reaction of olefins with the help of hydroperoxides has also been explored. The catalytic application of oxo-molybdenum(V)-corrolato complexes in the epoxidation reaction has not been reported earlier. A mechanism has been proposed to explain the experimental findings.
- Nayak, Manisha,Nayak, Panisha,Sahu, Kasturi,Kar, Sanjib
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- Stereoinversion of Unactivated Alcohols by Tethered Sulfonamides
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The direct, catalytic substitution of unactivated alcohols remains an undeveloped area of organic synthesis. Moreover, catalytic activation of this difficult electrophile with predictable stereo-outcomes presents an even more formidable challenge. Described herein is a simple iron-based catalyst system which provides the mild, direct conversion of secondary and tertiary alcohols to sulfonamides. Starting from enantioenriched alcohols, the intramolecular variant proceeds with stereoinversion to produce enantioenriched 2- and 2,2-subsituted pyrrolidines and indolines, without prior derivatization of the alcohol or solvolytic conditions.
- Marcyk, Paul T.,Jefferies, Latisha R.,AbuSalim, Deyaa I.,Pink, Maren,Baik, Mu-Hyun,Cook, Silas P.
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supporting information
p. 1727 - 1731
(2019/01/21)
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- TREATMENTS FOR RESISTANT ACNE
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The present disclosure relates generally to novel molecules, compositions, and formulations for treatment of bacterial infections in general and more specifically to bacterial infections with antibiotic resistant pathogens
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Paragraph 00274
(2015/09/23)
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- Bioproduction of chiral epoxyalkanes using styrene monooxygenase from rhodococcus sp. ST-10 (RhSMO)
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We describe the enantioselective epoxidation of straight-chain aliphatic alkenes using a biocatalytic system containing styrene monooxygenase from Rhodococcus sp. ST-10 and alcohol dehydrogenase from Leifsonia sp. S749. The biocatalyzed enantiomeric epoxidation of 1-hexene to (S)-1,2-epoxyhexane (44.6 mM) using 2-propanol as the hydrogen donor was achieved under optimized conditions. The biocatalyst had broad substrate specificity for various aliphatic alkenes, including terminal, internal, unfunctionalized, and di- and tri-substituted alkenes. Here, we demonstrate that this biocatalytic system is suitable for the efficient production of enantioenriched (S)-epoxyalkanes.
- Toda, Hiroshi,Imae, Ryouta,Itoh, Nobuya
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p. 3443 - 3450
(2015/02/05)
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- Photoinduced Alignment of Ferroelectric Liquid Crystals Using Azobenzene Polymer Networks of Polyethers and Polyepoxides
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Several divinyl ether and diepoxide monomers bearing an azobenzene moiety were synthesized and used to investigate the photoalignment of a ferroelectric liquid crystal (FLC) with no use of surface orientation layers. Azobenzene polymer networks, obtained by cationic polymerization of the monomers dissolved in the FLC host and exposed to linearly polarized irradiation, were found to be able to induce and stabilize a bulk alignment of FLC. Photoinduced reorientation of the FLC can also be achieved by changing the polarization of irradiation light, but in contrast with the use of chiral azobenzene poly(meth)acrylates,1 the results suggest a mechanism based on the formation of an anisotropic azobenzene polyether or polyepoxide network for the commanding effect on the FLC alignment.
- Sevigny, Sonia,Bouchard, Luc,Motallebi, Shahrokh,Zhao, Yue
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p. 9033 - 9041
(2007/10/03)
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- Alkyliron and Alkylcobalt Reagents, IX. - Rearrangement of Aliphatic Terminal Epoxides to Methyl Ketones by Iron Alkyl Reagents instead of Co2(CO)8 or Noble Metal Catalysts
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The highly selective rearrangement of aliphatic terminal epoxides to methyl ketones, hitherto possible only with Co2(CO)8 or noble metal catalysts, occurs smoothly with Me4FeLi2, Me3FeLi, or the catalytic systems (R = Me, Bu).This was demonstrated by the rearrangement of 1-decene oxide (1) to 2-decanone (2) (yield 80-81percent; Table 1) and 6-bromo-1-hexene oxide (5) to 6-bromo-2-hexanone (6) (yield 78percent, Me4FeLi2 applied only).The competition reaction of Me4FeLi2 with 1 and 2-octanone (8) (mole ratio 0.5:1:1) led to 87percent 2-methyl-2-octanol (9) and not to the rearrangement 1 --> 2.This indicates that Me4FeLi2 - in contrast to the opposite behavior of organo cuprates - reacts faster with ketones than with the aliphatic terminal epoxides.By treatment of 1 with methyl derivatives of Mn(II), Co(II), and Ni(II) or with Bu4FeLi2 (Table 2) other products (3, 4) besides 2 were formed.The rearrangement of 1 with Me4FeLi2 is assumed to start with an oxidative addition and yields 2 as its Li or Fe enolate (trapped with acetanhydride to give 64percent of 20) after reductive elimination of CH4.The catalytic rearrangement of 1 with very probably occurs in an analogous manner with an super-ate complex Me4FeLi2(MeLi)n as the active species and the Li enolate of 2 as end product (Scheme 4).The aromatic terminal epoxides styrene oxide and α-methylstyrene oxide give various products in the reaction with Me4FeLi2 or Me3FeLi, including the deoxygenation products styrene and α-methylstyrene.These products are exclusively formed on treatment of the epoxides with Me4MnLi2. (Prepared, hitherto in the literature not described compounds: 7 and 10-15.) - Key Words: Organoiron compounds / Iron catalysts / Ketone synthesis
- Kauffmann, Thomas,Neiteler, Christel,Neiteler, Gabriele
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p. 659 - 666
(2007/10/02)
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- CYCLIZATION OF 6-BROMO-1,2-EPOXYHEXANE PROMOTED BY METAL-HALOGEN EXCHANGE: UNEXPECTED REGIOSELECTIVITY
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Treatment of 6-bromo-l,2-epoxyhexane (1) with one equivalent of sec-butyllithium afforded a 95:5 mixture of cyclopentylmethanol (4): cyclohexanol in approximately 40percent yield.An analogous tandem metal-halogen exchange/cycloalkylation process using the oxirane derivative (2) of 6-iodo-1-hexene gave virtually the same mixture of alcohols in >60percent yield.
- Babler, James H.,Bauta, William E.
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p. 4323 - 4324
(2007/10/02)
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