- METHYLENEDIMAGNESIUM DIBROMIDE AS PRECURSOR OF METAL CARBENE COMPLEXES; PREPARATION OF TITANACYCLOBUTANES.
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The reaction of CH2(MgBr)2 with Cp2TiCl2 gives a titanium methylene complex which, similar to Tebbe's reagent, forms four-membered titana-heterocycles with alkenes and alkines.
- Bruin, J. W.,Schat, G.,Akkerman, O. S.,Bickelhaupt, F.
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Read Online
- Enantioselective Synthesis of Cyclopropanone Equivalents and Application to the Formation of Chiral β-Lactams
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Cyclopropanone derivatives have long been considered unsustainable synthetic intermediates because of their extreme strain and kinetic instability. Reported here is the enantioselective synthesis of 1-sulfonylcyclopropanols, as stable yet powerful equivalents of the corresponding cyclopropanone derivatives, by α-hydroxylation of sulfonylcyclopropanes using a bis(silyl) peroxide as the electrophilic oxygen source. This work constitutes the first general approach to enantioenriched cyclopropanone derivatives. Both the electronic and steric nature of the sulfonyl moiety, which serves as a base-labile protecting group and confers crystallinity to these cyclopropanone precursors, were found to have a crucial impact on the rate of equilibration to the corresponding cyclopropanone. The utility of these cyclopropanone surrogates is demonstrated in a mild and stereospecific formal [3+1] cycloaddition with simple hydroxylamines, leading to the efficient formation of chiral β-lactam derivatives.
- Jang, Yujin,Johnson, J. Drake,Jung, Myunggi,Lindsay, Vincent N. G.,Poteat, Christopher M.,Williams, Rachel G.
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supporting information
p. 18655 - 18661
(2020/08/21)
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- 1,2-Dibromotetrachloroethane: An efficient reagent for many transformations by modified Appel reaction
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An efficient and facile method has been developed for the synthesis of alkyl bromides from various alcohols under mild conditions using a triphenylphosphine (PPh 3) /1,2-dibromotetrachloroethane (DBTCE) complex in excellent yields and very short time (5 min). This method can also be applied for the transformation of chiral alcohols to their corresponding bromides in very high enantiomeric excess. The PPh 3 /DBTCE complex is also successfully applied to ring-opening reactions of cyclic ethers in mild conditions. Esterification, amidation, and formation of acid anhydrides under very mild experimental conditions are also successfully accomplished by following a modification of the Appel reaction protocol in this work.
- Essiz, Sel?uk,Da?tan, Arif
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p. 150 - 156
(2019/05/16)
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- CHEMICAL COMPOUNDS AS INHIBITORS OF INTERLEUKIN-1 ACTIVITY
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The present disclosure relates to novel sulfonylurea and sulfonyl thiourea compounds and related compounds and their use in treating a disease or condition responsive to modulation of cytokines such as IL-1β and IL-18, modulation of NLRP3 or inhibition of the activation of NLRP3 or related components of the inflammatory process.
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Paragraph 00532; 00533; 00534
(2018/08/12)
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- PYRAZOLE AMIDE DERIVATIVE
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The present invention relates to a novel compound having a function of inhibiting RORγ activity. The present invention also relates to pharmaceutical composition comprising the compound, a use of the compound in treating or preventing autoimmune diseases, inflammatory diseases, metabolic diseases, or cancer diseases.
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Page/Page column 100
(2015/09/28)
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- PEPTIDOMIMETIC COMPOUNDS AND ANTIBODY-DRUG CONJUGATES THEREOF
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This invention relates to peptidomimetic linkers and anti-body drug conjugates thereof, to pharmaceutical compositions containing them, and to their use in therapy for the prevention or treatment of cancer.
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Page/Page column 94
(2015/07/07)
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- Mild one-step synthesis of dibromo compounds from cyclic ethers
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A novel one-step method for mildly converting cyclic ethers into dibromo compounds is reported. Alcohols, oximes, aldehydes, and ketones are known to react under Appel or Corey-Fuchs reaction conditions, but apparently these have never been applied to oxetanes or larger cyclic ethers. Treatment of 3,3-dimethyloxetane (1) with tetrabromomethane and triphenylphosphine gave the corresponding dibromo compound 1,3-dibromo-2,2-dimethylpropane (2). The less-strained homologue oxolane (6) was also reacted giving 1,4-dibromobutane (7) in a 93% yield. Mechanistic interpretations are offered to explain the observed reaction rates of the conversions described.
- Billing, Peter,Brinker, Udo H.
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p. 11227 - 11231
(2013/02/23)
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- Synthesis, biological evaluation and docking studies of octane-carboxamide based renin inhibitors with extended segments toward S3′ site of renin
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Eighteen octane-carboxamide based renin inhibitors with extended segments for mimicking P3′ unit of angiotensinogen have been synthesized. The biological evaluation identified novel renin inhibitors with more potent activity than aliskiren. Molecular docking studies showed that the extended amide-tails matched the P3′ position of angiotensinogen and exerted interactions with the S3′ site of renin. An unexpected π-π stacking interaction was observed during docking study for compound 9r, which could be a reasonable explanation for the outstanding potency of this compound. Further study is in progress to reveal a feasibility for developing novel renin inhibitors based on the possible non-classical interactions between the ligands and the new subsite of renin.
- Wu, Yong,Shi, Chen,Sun, Xiaowei,Wu, Xiaoming,Sun, Hongbin
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experimental part
p. 4238 - 4249
(2011/08/09)
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- Preparation and properties of metallacyclobutanes of nickel and palladium
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Bis(phosphine)-3,3-dimethylnickela- and palladacyclobutanes have been prepared by intramolecular C-H insertion reaction of the corresponding dineopentyl metal complexes.Nickelacyclobutane complexes decompose when heated thereby undergoing competitive carb
- Miyashita, Akira,Ohyoshi, Mayumi,Shitara, Hiroaki,Nohira, Hiroyuki
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p. 103 - 112
(2007/10/02)
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- Cyclometallation Reactions in Neopentyl and Trimethylsilylmethyl Systems of Rhodium(III) and Iridium(III). Formation and X-Ray Crystal Structures of the Four-membered Metallacycles and
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The interaction of 5-C5Me5)(PPh3)> with Mg(CH2CMe3)Cl in pentane gives the rhodacyclobutane (2).The analogous reaction of 5-C5Me5)-(PPh3)> (M = Rh or Ir) with Mg(CH2SiMe3)Cl allows the isolation of the dialkyl derivatives 5-C5Me5)(PPh3)>.Thermolysis of 5-C5Me5)(PPh3)> in cyclohexane leads to the iridasilacyclobutane derivative (6).The mechanism of formation of the metallacyclobutane derivatives is discussed.The X-ray crystal structures of (2) and (6) have been determined.The two metallacycle compounds give isostructural crystals belonging to the P21/n space group with four molecules in the unit cell of dimensions for (2): a = 17.199(6), b = 10.987(4), c = 16.06495) Angstroem, β = 109.54(2)deg; (6): = 17.098(7), b = 11.294(5), c= 15.977(7) Angstroem, β = 108.17(2)deg.Their crystal structures refined to R = 0.0441 and 0.0389 for (2) and (6) respectively, are built up of deformed 'three-legged piano stools', one leg being the M-P bond , the other two being the M-C ? bonds of the metallacyclobutane ring with C-Rh-C = 66.8(2) and C-Ir-C = 77.3(4)deg.These rings are puckered: angle between M-C...C and E-C...C = 16.5(4) and 18.9(6)deg for (2) (E = C) and (6) (E = Si), respectively.
- Andreucci, Luca,Diversi, Pietro,Ingrosso, Giovanni,Lucherini, Antonio,Marchetti, Fabio,et al.
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p. 477 - 488
(2007/10/02)
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- C(sp3)-H and C(sp2)-H Bond Activation in the (Pentamethylcyclopentadienyl)rhodium(III) System: Formation of (2,2-Dimethylpropane-1,3-diyl)(pentamethylcyclopentadienyl)(triphenylphosphine)rhodium and Neopentyl(pentamethylcyclopentadie
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The rhodacyclobutane and the ortho-metallated compound are formed in the reaction of 5-C5Me5)(PPh3)> with LiCH2CMe3 or XMgCH2CMe3.
- Diversi, Pietro,Ingrosso, Giovanni,Lucherini, Antonio,Fasce, Daniela
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p. 945 - 946
(2007/10/02)
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