- A Hg(OTf)2-Catalyzed Enolate Umpolung Reaction Enables the Synthesis of Coumaran-3-ones and Indolin-3-ones
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The potential of mercury catalysis has been extended to the arena of enolate umpolung reactions for the first time by the generation of enolonium species via Hg(OTf)2-catalyzed N-oxide addition to alkynes. The enolonium species formed can undergo intramolecular nucleophilic attack by hydroxyl or amino groups, leading to the synthesis of various coumaran-3-ones and indolin-3-ones.
- Dai, Ning,Hu, Weican,Qian, Guoying,Rong, Zhouting
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p. 3286 - 3290
(2020/04/21)
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- OXIME COMPOUND, PHOTOSENSITIVE COMPOSITION, COLOR FILTER, METHOD FOR PRODUCTION OF THE COLOR FILTER, AND LIQUID CRYSTAL DISPLAY ELEMENT
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Provided are an oxime compound represented by General Formula (1), a photosensitive composition containing the oxime compound as a photopolymerization initiator, a production method for a color filter using the photosensitive composition, and a color filt
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Page/Page column 66
(2009/12/05)
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- Synthesis, resolution, and application of 2,2′-bis(diphenylphosphino) -3,3′-binaphtho[b]furan (BINAPFu)
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(±)-2,2′-Bis(diphenylphosphino)-3,3′-binaphtho[2,1-b] furan (BINAPFu) was synthesized from 2-naphthoxyacetic acid in a five-step sequence in 62% overall yield. A variety of reported resolution procedures for biaryl bisphosphines did not work with (±)-BINAPFu; thus, a new resolution method was developed, involving the Staudinger reaction of the aforementioned racemate of BINAPFu with an enantiopure camphor sulfonyl azide derivative. The resulting diastereomeric phosphinimines were separated by flash chromatography. Subsequent hydrolysis to the corresponding bis-phosphine oxide and trichlorosilane reduction provided enantiopure BINAPFu. The absolute stereochemical configuration of BINAPFu was established by X-ray crystallography. BINAPFu was compared with commercially available 2,2′-bis(diphenylphosphino)-1,1′-binaphthalene (BINAP) in Pd(0)-catalyzed intermolecular Heck reactions. Investigation of the Heck arylation of 2,3-dihydrofuran showed BINAPFu to be more efficacious than BINAP in dioxane at 30°C. A variety of phosphorus selenides were prepared, and the 1JP-Se coupling constants measured, to obtain a comparative scale of parent phosphine basicity. The phosphorus atoms in BINAPFu were found to be electron deficient when compared with BINAP but slightly more electron rich than trifurylphosphine.
- Andersen, Nell G.,Parvez, Masood,McDonald, Robert,Keay, Brian A.
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p. 145 - 161
(2007/10/03)
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- Facile synthesis of novel fluorescence active 12H-benzo[e]indolo[3,2-b] benzofuran and its derivatives
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Successful preparation of novel penta-heterocyclic compounds, 12H-benzo[e]indolo[3,2-b]benzofurans, in good yields is reported. The synthesized compounds with planar geometry and extended conjugation exhibit excellent fluorescence properties.
- Karnik,Upadhyay
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p. 1345 - 1348
(2007/10/03)
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- Synthesis, resolution, and applications of 2,2′-bis(diphenylphosphino)-3,3′-binaphtho[2,1-d]furan
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A short five-step synthesis of (±)-2,2′-bis(diphenylphosphino)-3,3′-binaphtho[2,1-b]furan (BINAPFu, 1) starting from 2-naphthoxyacetic acid is reported. The resolution of BINAPFu 1 was possible using our newly developed resolution procedure for phosphines
- Andersen, Neil G.,Parvez, Masood,Keay, Brian A.
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p. 2817 - 2820
(2007/10/03)
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- Bicyclic N-hydroxyurea inhibitors of 5-lipoxygenase: Pharmacodynamic, pharmacokinetic, and in vitro metabolic studies characterizing N-hydroxy-N-(2,3-dihydro-6-(phenylmethoxy)-3-benzofuranyl)urea
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A series of N-hydroxyurea derivatives have been prepared and examined as inhibitors of 5-lipoxygenase. Oral activity was established by examining the inhibition of LTB4 biosynthesis in an ex vivo assay in the mouse. The pharmacodynamic performance in the mouse of selected compounds was assessed using an ex vivo LTB4 assay and an adoptive peritoneal anaphylaxis assay at extended pretreat times. Compounds with an extended duration of action were reexamined as the individual enantiomers in the ex vivo assay, and the (S) enantiomer of N-hydroxy-N-[2,3-dihydro-6-(phenylmethoxy)-3-benzofuranyl]urea, (+)-1a (SB 202235), was selected as the compound with the best overall profile. Higher plasma concentrations and longer plasma half-lives were found for (+)-1a relative to its enantiomer in the mouse, monkey, and dog. In vitro metabolic studies in mouse liver microsomes established enantiospecific glucuronidation as a likely mechanism for the observed differences between the enantiomers of 1a. Enantioselective glucuronidation favoring (-)-1a was also found in human liver microsomes.
- Adams, Jerry L.,Garigipati, Ravi S.,Sorenson, Margaret,Schmidt, Stanley J.,Brian, William R.,Newton, John F.,Tyrrell, Kathy A.,Garver, Eric,Yodis, Lee A.,Chabot-Fletcher, Marie,Tzimas, Maritsa,Webb, Edward F.,Breton, John J.,Griswold, Don E.
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p. 5035 - 5046
(2007/10/03)
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- LIPOXYGENASE INHIBITORS
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Tricyclic hydroxyurea and hydroxamate compounds, pharmaceutical compositions, and their use as as inhibitors of the oxidation of polyunsaturated fatty acids, such as by inhibition on the 5-lipoxygenase enzyme, and treatment of diseases therein.
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