- Continuous Flow Synthesis of 2H-Thiopyrans via thia-Diels–Alder Reactions of Photochemically Generated Thioaldehydes
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Herein, we report a novel protocol for the photochemical generation of thioaldehydes in a continuous flow process which were in situ reacted with electron rich 1,3-butadienes in thia-Diels–Alder reactions. A broad range of 3,6-dihydro-2H-thiopyrans were formed as products in much higher yields and productivities as compared to classical batch processes. Moreover, greatly reduced reaction times and a facile large-scale preparation of products were achieved by fully exploiting the advantages of continuous flow technology.
- Sachse, Florian,Gebauer, Konrad,Schneider, Christoph
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- Visible-light induced metal-free cascade Wittig/hydroalkylation reactions
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Cascade reactions are green and powerful transformations for building multiple carbon-carbon bonds in one step. Through a relay olefination and radical addition process, we were able to develop the cascade Wittig/hydroalkylation reactions induced by visible light. This metal-free radical approach features mild conditions, robustness, and excellent functionality compatibility. It allows access to saturated C3 homologation products directly from aldehydes or ketones. The synthetic utility of this method is demonstrated by a two-step synthesis ofindolizidine 209D.
- Miao, Pannan,Li, Ruining,Lin, Xianfeng,Rao, Liangming,Sun, Zhankui
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p. 1638 - 1641
(2021/03/09)
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- Synthesis of Unsymmetrical 1,4-Dicarbonyl Compounds by Photocatalytic Oxidative Radical Additions
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Herein we report a photocatalytic oxidative radical addition reaction for the synthesis of unsymmetrical 1,4-dicarbonyl compounds. This reaction utilizes a desulfurization process to generate electrophilic radicals, which add to α-halogenated alkenes and undergo further oxidation to deliver 1,4-dicarbonyl compounds. This mild and highly efficient method provides a valuable alternative to known strategies.
- Dong, Ya,Li, Ruining,Zhou, Junliang,Sun, Zhankui
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p. 6387 - 6390
(2021/08/23)
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- Synthesis of 5-Membered Sulfur Heterocycles via Tin-Catalyzed Annulation of Mercapto Ketones with Activated Alkenes
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Efficient conversion of α-mercapto ketones 1 with activated alkenes 2 into S-heterocycles was developed with Sn(Oct)2-2MeOH acting as a catalyst. Two types of products, dihydrothiophene 3 and thiolane 4, were obtained. The selectivity of the products was dependent on the reaction temperature and on the rearrangement of the S-heterocycles from 3 to 4 under heating conditions. The dihydrothiophenes 3 were transformed into useful thiolactones 6-8 and thiophene 9.
- Suzuki, Itaru,Sakamoto, Yuki,Seo, Yuta,Ninomaru, Yoriko,Tokuda, Kodai,Shibata, Ikuya
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p. 2759 - 2769
(2020/01/31)
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- Site-Selective and Enantioselective α,β,γ-Functionalization of 5-Alkylidenefuran-2(5 H)-ones: A Route to Polycyclic γ-Lactones
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A new strategy for a direct α,β,γ-functionalization of the γ-lactone framework in the corresponding 5-alkylidenefuran-2(5H)-ones is reported. The developed approach is based on a stereocontrolled cascade reaction with 2-mercaptocarbonyl compounds proceedi
- Skrzyńska, Anna,Frankowski, Sebastian,Moczulski, Marek,Drelich, Piotr,Albrecht, ?ukasz
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supporting information
p. 1248 - 1252
(2019/02/26)
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- Br?nsted-base-catalyzed remote cascade reactivity of 2,4-dienones-asymmetric synthesis of tetrahydrothiophenes
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This study demonstrates that the remote cascade functionalization of 2,4-dienones can be realized by employing Br?nsted base catalysis. The developed cascade involving 1,6-addition followed by the intramolecular aldol reaction provides a straightforward a
- Przydacz, Artur,Kowalczyk, Rafa?,Albrecht, ?ukasz
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p. 9566 - 9569
(2017/11/30)
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- α-Methylphenacyl thioesters as convenient thioacid precursors
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α-Methylphenacyl (Mpa) thioesters are described as precursors of thioacids. Mpa thioesters are accessible via the condensation of carboxylic acids and phenacyl thiol, which is easily prepared without column chromatography. The Mpa thioesters are selectively deprotected by reduction with zinc dust in the presence of conventional thioacid protecting groups. In addition, the Mpa group exhibits orthogonal reactivity to the Boc group. These features are expected to facilitate the preparation of complex thioacids, including those in peptides.
- Hatanaka, Toru,Yuki, Ryosuke,Saito, Ryota,Sasaki, Kaname
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p. 10589 - 10592
(2016/11/30)
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- Nitrophenyls and related compounds and thimerosal for the inhibition of immune related cell or tissue destruction
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Composition containing a nitrophenyl compound or thimerosal for inhibiting phagocytosis of blood cells. The use of a nitrophenyl compound or thimerosal to inhibit phagocytosis of blood cells in a host having an auto or alloimmune disease.
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Page/Page column 6-7
(2008/06/13)
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- Novel disulfides with antitumour efficacy and specificity
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Some disulfides have previously been shown to possess antifungal and/or antileukaemic activity. Importantly, this cytotoxicity can be selective. We have previously shown that a subset of these compounds does not block the proliferative potential of normal
- Griffiths, Rebecca,Wong, W. Wei-Lynn,Fletcher, Stephen P.,Penn, Linda Z.,Langler, Richard F.
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p. 128 - 136
(2007/10/03)
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- A general and mild synthesis of thioesters and thiols from halides
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The conversion of a wide variety of halides to thioesters by reaction with potassium thiocetate under mild conditions is described, and the generality of the method is demonstrated.
- Zheng, Tu-Cai,Burkart, Maureen,Richardson, David E.
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p. 603 - 606
(2007/10/03)
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- Inhibition of human cytomegalovirus protease N(o) with monocyclic β- lactams
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Monocyclic β-lactams have been identified as potent and selective inhibitors of the human cytomegalovirus protease (HCMV) N(o). Two series of these inhibitors are described, a peptidyl series of compounds and non- peptidic molecules featuring lower molecular weights. The SAR work that lead to the discovery of these inhibitors, together with their synthesis is also disclosed.
- Deziel,Malenfant
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p. 1437 - 1442
(2007/10/03)
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- Amides for the treatment of atherosclerosis
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This invention provides amide compounds as inhibitors of acyl-Coenzyme A: cholesterol O-acyltransferase (ACAT), pharmaceutical compositions containing such compounds, processes for the preparation of such compounds, and the use of such compounds as antihypercholesterolemic and/or antiatherosclerotic agents.
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- ACAT inhibitors derived from hetero-Diels-Alder cycloadducts of thioaldehydes
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Acyl-CoA:cholesterol acyltransferase (ACAT) is the enzyme largely responsible for intracellular cholesteror esterification. A systemic inhibitor of ACAT is believed to be able to slow or even reverse the atherosclerotic process. Towards that goal, a series of cyclic sulfides, derived from the hetero-Diels-Alder reaction of thioaldehydes with 1,3-dienes, and bearing carboxamide substituents, were prepared and evaluated for in vitro (in several tissues and species) and ex vivo ACAT inhibition. Minor changes in subsequent structure were found to have a significant effect in optimization of the biological activity of this series of compounds.
- Wilde, Richard G.,Billheimer, Jeffrey T.,Germain, Sandie J.,Hausner, Elizabeth A.,Meunier, Paul C.,Munzer, Deborah A.,Stoltenborg, Janet K.,Gillies, Peter J.,Burcham, Deborah L.,Huang, Shiew-Mai,Klaczkiewicz, John D.,Ko, Soo S.,Wexler, Ruth R.
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p. 1493 - 1513
(2007/10/03)
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- Direct synthesis of thiols from halides and epoxides using hydrosulfide exchange resin in methanol
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Various thiols are prepared directly from the corresponding alkyl halides and epoxides using hydrosulfide exchange resin in methanol in the presence of equimolar amounts of triethylammonium chloride at room temperature. The reaction not only proceeds with unique chemoselectivity, but also gives better yields of thiols than most commonly used indirect methods and has an additional advantage of a simple workup.
- Choi,Yoon
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p. 373 - 375
(2007/10/02)
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- A Method for Mild Photochemical Oxidation; Conversion of Phenacyl Sulfides into Carbonyl Compounds
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Sunlamp irradiation of phenacyl sulfides PhCOCH2SCHRR' affords thiocarbonyl compounds S=CRR' that can be trapped in high yield by using the nitronate CH3CH=N+(OTBS)O-; the heterocycle 3 resulting from 1,3-dipolar cycloaddition is cleaved rapidly by fluoride ion to give ketones or aldehydes.
- Vedejs, E.,Perry, D. A.
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p. 573 - 575
(2007/10/02)
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