20678-26-6Relevant articles and documents
α-Angelica lactone catalyzed oxidation of benzylic sp3C-H bonds of isochromans and phthalans
Das, Utpal,Deepake, Siddharth K.,Kumar, Pawan,Thatikonda, Thanusha
supporting information, p. 4046 - 4050 (2020/06/09)
A metal-free organocatalytic system has been developed for highly efficient benzylic C-H oxygenations of cyclic ethers using oxygen as an oxidant. This oxidation reaction utilizes α-angelica lactone as a low cost/low molecular weight catalyst. The optimized reaction conditions allow the synthesis of valued isocoumarins and phthalides from readily available precursors in good yields. Mechanistic studies indicate that the reaction pathway likely involves a radical processviaa peroxide intermediate.
Visible light mediated oxidation of benzylic sp3 C-H bonds using catalytic 1,4-hydroquinone, or its biorenewable glucoside, arbutin, as a pre-oxidant
Finney, Laura C.,Mitchell, Lorna J.,Moody, Christopher J.
, p. 2242 - 2249 (2018/05/28)
Benzylic ethers undergo a visible light induced C-H activation and oxygen insertion to give the corresponding benzoate esters in moderate to good yields. The conditions employ substoichiometric amounts of 1,4-hydroquinone with copper(ii) chloride dihydrate as an electron-transfer mediator, oxygen as the terminal oxidant and dimethyl carbonate as solvent under visible light irradiation. The naturally occurring glucoside, arbutin, which is commercially available or can be accessed via extraction of the leaves of bearberry (Arctostaphylos uva-ursi) or elephant ears (Bergenia crassifolia) can be used as a biorenewable source of 1,4-hydroquinone. The methodology exploits the increase in oxidizing ability of quinones upon irradiation with visible light, and offers a sustainable alternative for the late stage oxidative functionalization of benzylic C-H bonds. It is applicable to a range of cyclic benzylic ethers such as isochromans and phthalans, and simple benzyl alkyl ethers. It can also be applied in the oxidation of benzylic amines into amides, and of diarylmethanes into the corresponding ketones. Mechanistic studies suggest that the reaction proceeds by H-abstraction by the photo-excited triplet benzoquinone to give a benzylic radical that subsequently reacts with molecular oxygen.
Stereoselective synthesis of 2H-chromans by reductive deoxygenation of differently substituted 2-sulfinylmethylchroman-2-ols
Hernandez-Torres, Gloria,Carreno, M. Carmen,Urbano, Antonio,Colobert, Francoise
supporting information; experimental part, p. 3864 - 3877 (2011/09/30)
Good-to-excellent diastereoselectivies have been achieved in the synthesis of 2H-chromans by Et3SiH/TMSOTf reductive deoxygenation of differently substituted 2-sulfinylmethylchroman-2-ols and their methyl ketals. The influence of both electron-
NOVEL SUBSTITUTED TETRAHYDRONAPHTHALENES, PROCESS FOR THE PREPARATION THEREOF AND THE USE THEREOF AS MEDICAMENTS
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Page/Page column 79, (2010/10/19)
The invention relates to substituted tetrahydronaphthalenes and derivatives thereof, and also to the physiologically compatible salts and physiologically functional derivatives thereof, to preparation thereof, to medicaments comprising at least one inventive substituted tetrahydronaphthalene or derivative thereof, and to the use of the inventive substituted tetrahydronaphthalenes and derivatives thereof as medicaments.
Enzymatic Baeyer-Villiger oxidation of Benzo-Fused ketones: Formation of regiocomplementary lactones
Rioz-Martinez, Ana,De Gonzalo,Torres Pazmino, Daniel E.,Fraaije, Marco W.,Gotor, Vicente
supporting information; experimental part, p. 2526 - 2532 (2009/09/25)
Baeyer-Villiger monooxygenases (BVMOs) are enzymes that are known to catalyse the Baeyer-Villiger oxidation of ketones in aqueous media using O2 as oxidant. Herein, we describe the oxidation of a set of diverse benzo-fused ketones by three different BVMOs
NOVEL AMINOALCOHOL-SUBSTITUTED ARYLDIHYDROISOQUINOLINONES, PROCESS FOR THEIR PREPARATION AND THEIR USE AS MEDICAMENTS
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Page/Page column 100, (2008/06/13)
The invention relates to aminoalcohol-substituted aryldihydroisoquinolinones and their derivatives, and their physiologically tolerated salts and physiologically functional derivatives, their preparation, medicaments comprising at least one aminoalcohol-substituted aryldihydroisoquinolinone of the invention or its derivative, and the use of the aminoalcohol- substituted aryldihydroisoquinolinones of the invention and their derivatives as MCH antagonists.
Dopamine/serotonin receptor ligands. 121: SAR studies on hexahydro-dibenz[d,g]azecines lead to 4-chloro-7-methyl-5,6,7,8,9,14- hexahydrodibenz[d,g]azecin-3-ol, the first picomolar D5-selective dopamine-receptor antagonist
Mohr, Patrick,Decker, Michael,Enzensperger, Christoph,Lehmann, Jochen
, p. 2110 - 2116 (2007/10/03)
Hydroxylated, methoxylated, and/or chlorinated 7-methyl-5,6,7,8,9,14- hexahydrodibenz[d,g]azecines were generally synthesized out of substituted 2-phenylethylamines and isochromanones by Bischler-Napieralski cyclization of the resulting benzamides to dibenzoquinolizines and the quaternization and cleavage of the central C-N bond under Birch conditions. Chlorination of 2-phenylethylamines was useful for the site direction of cyclization, but chlorine atoms were removed under Birch conditions so that chlorination had to be repeated to get the respective chlorinated dibenz[d,g]azecines. The target compounds were tested for their affinity at the different human-cloned dopamine-receptor subtypes (D1 family, D2 family). Generally, hydroxylation and chlorination of the dibenz-azecines increased affinities significantly. 1-Chloro-2-hydroxyhexahydro-dibenz[d,g]azecine was a subnanomolar antagonist at both subtype families. 4-Chloro-3-hydroxy-7-methyl-5, 6,7,8,9,14-hexahydro-dibenz[d,g]azecine was identified as the most potent and selective dopamine D5 receptor ligand described to date with K i(D1) = 0.83, Ki(D2L) = 4.0, K i(D3) = 24.6, Ki(D4) = 5.2 nM, and Ki(D5) = 57 pM (radioligand binding experiments), respectively.
Determination cinetique de la nature du conformere reactif dans l'hydrolyse des orthoesters
Lamaty, Gerard,Moreau, Claude,Mouloungui, Zephirin
, p. 2643 - 2650 (2007/10/02)
The rates of hydrolysis of the following orthoesters, 6 or 7-substituted 1,1-diethoxy-3,4-dihydrobenzo-2-pyrans (R=6-MeO, H, 7-MeO, 7-NO2 and 6-NO2) were determined at 27 deg C in water/dioxan (2:1 by volume).The catalytic rate constants as well as the Hammett ρ constants show that the rate-determining step is the formation of a cyclic carboxonium ion intermediate and constitute a kinetic piece of evidence for the determination of the nature of the reactive conformer in hydrolysis of 2,2-dialkoxy tetrahydropyran orthoesters.
