- Diastereoselective Photoredox-Catalyzed [3 + 2] Cycloadditions of N-Sulfonyl Cyclopropylamines with Electron-Deficient Olefins
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A highly diastereoselective, visible-light-induced [3 + 2] cycloaddition between N-sulfonyl cyclopropylamines and electron-deficient olefins is reported. The reactions proceed via the oxidation of a sulfonamide aza-anion by an organic photocatalyst to generate a nitrogen-centered radical. Strain-induced ring opening and intermolecular addition to the olefin generate an intermediate carbon-centered radical that is reduced to an anion prior to 5-exo cyclization. This enables a highly diastereoselective construction of trans-cyclopentanes possessing synthetically useful functional groups.
- White, Dawn H.,Noble, Adam,Booker-Milburn, Kevin I.,Aggarwal, Varinder K.
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supporting information
p. 3038 - 3042
(2021/05/04)
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- Pd-Catalyzed Cascade Reactions of Aziridines: One-Step Access to Complex Tetracyclic Amines
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The combination of palladium catalysis and thermal cycloaddition is shown to transform tricyclic aziridines into complex, stereodefined tetracyclic products in a single step. This highly unusual cascade process involves a diverted Tsuji-Trost sequence leading to a surprisingly facile intramolecular Diels-Alder reaction. The starting materials are accessible on multigram scales from the photochemical rearrangement of simple pyrroles. The tetracyclic amine products can be further elaborated through routine transformations, highlighting their potential as scaffolds for medicinal chemistry.
- Booker-Milburn, Kevin I.,Knowles, Jonathan P.,Latter, Francesca,Schwarz, Maria,Steeds, Hannah G.
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supporting information
p. 4986 - 4990
(2021/07/19)
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- β,γ-Diaryl α-methylene-γ-butyrolactones as potent antibacterials against methicillin-resistant Staphylococcus aureus
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A selected series of racemic α-methylene-γ-butyrolactones (AMGBL) synthesized via allylboration or allylindation reactions were screened against methicillin-resistant Staphylococcus aureus (MRSA) USA300. Unlike natural AMGBLs, such as parthenolide, synthe
- Abutaleb, Nader S.,Hamann, Henry J.,Pal, Rusha,Ramachandran, P. Veeraraghavan,Seleem, Mohamed N.
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- COMPOSITIONS AND METHODS FOR PROTEIN LABELING, MODIFICATION, ANALYSIS, AND TARGETED DELIVERY
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The invention relates to chemically reactive and/or biologically active compounds, reagents and compositions thereof. More particularly, the invention provides novel reagents that are useful in chemical synthesis, functionalization, delivery, probing and/or analytical measurements of small molecule drugs, proteins, antibodies and other biomolecules. The invention provides novel biologically active agents useful as diagnostics or therapeutics, and related composition and methods of uses thereof.
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Paragraph 00224
(2020/01/24)
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- The alkoxycarbonylation of protected propargyl alcohols
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Palladium-catalyzed alkoxycarbonylation of the C≡C triple bond of propargyl alcohol is a sustainable synthetic approach to 2-(hydroxymethyl)acrylates, a family of valuable intermediates. The developed synthetic protocol includes protection of the alcoholic function of the alkyne before its carbonylation in the presence of Drent's catalytic system. Protection step effectively extends the catalyst life hence enhancing the practical applicability of the reaction. The effectiveness of some different protecting groups (benzyl, acetyl and trimethylsilyl) has been assessed and the influence of the reaction parameters investigated.
- Alam, Md. Mahbubul,Beghetto, V.,Bertoldini, M.,Scrivanti, A.,Sole, R.
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- Sequential Palladium-Catalyzed Allylic Alkylation/retro-Dieckmann Fragmentation Strategy for the Synthesis of α-Substituted Acrylonitriles
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A straightforward synthesis of α-substituted acrylonitriles is described using 4-cyano-3-oxotetrahydro-thiophene (c-THT) as an acrylonitrile surrogate. This unprecedented two-step sequence featuring a palladium-catalyzed allylic alkylation (Pd-AA) and a retro-Dieckmann fragmentation provides a general entry into diversely substituted 1,4-dienes.
- Katsina, Tania,Sharma, Sachi Prem,Buccafusca, Roberto,Quinn, Derek J.,Moody, Thomas S.,Arseniyadis, Stellios
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supporting information
p. 9348 - 9352
(2019/11/20)
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- Modular 1,1′-Ferrocenediyl-cored P-Stereogenic Diphosphines: ′′JDayPhos′′ Series and its Use in Rhodium(I)-Catalyzed Hydrogenation
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A novel ferrocene-based P-stereogenic diphospine ligand series dubbed JDayPhos was developed, which rhodium(I) complexes of some of its members exhibited excellent enantioselectivity (up to >99% ee) and high activity in asymmetric hydrogenation of β-unsubstituted or -substituted itaconates and α-methylene-γ-oxo-carboxylates. (Figure presented.).
- Poklukar, Ga?per,Stephan, Michel,Mohar, Barbara
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supporting information
p. 2566 - 2570
(2018/05/16)
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- Palladium-Catalyzed Asymmetric Allylic Alkylation of 4-Substituted Isoxazolidin-5-ones: Straightforward Access to β2,2-Amino Acids
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We report here an unprecedented and highly enantioselective palladium-catalyzed allylic alkylation applied to 4-substituted isoxazolidin-5-ones. Ultimately, the process provides a straightforward access to β2,2-amino acids bearing an all-carbon quaternary stereogenic center in great yields and a high degree of enantioselectivity.
- Nascimento de Oliveira, Marllon,Arseniyadis, Stellios,Cossy, Janine
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supporting information
p. 4810 - 4814
(2018/03/21)
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- Highly Enantioselective, Base-Free Synthesis of α-Quaternary Succinimides through Catalytic Asymmetric Allylic Alkylation
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The synthesis of diversely substituted five-membered ring succinimide derivatives is reported featuring a direct, base-free, palladium-catalyzed asymmetric allylic alkylation. The method allows a straightforward access to the desired heterocyclic scaffold bearing an all-carbon α-quaternary stereogenic center in high yields and good to excellent enantioselectivities. To further demonstrate the synthetic utility of the method, the allylated products were further converted to various versatile chiral building blocks, including a chiral pyrrolidine and a spirocyclic derivative, using selective transformations.
- Song, Tao,Arseniyadis, Stellios,Cossy, Janine
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supporting information
p. 8076 - 8080
(2018/06/15)
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- ALPHA-(UNSATURATED ALKOXYALKYL) ACRYLATE COMPOSITION AND PROCESS FOR PRODUCTION THEREOF
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An α-(unsaturated alkoxyalkyl) acrylate composition is provided which enables an α-(unsaturated alkoxyalkyl) acrylate product to be stored at a high purity for an extended period of time and can fully suppress problems such as coloration and gelation from
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Page/Page column 63
(2012/02/15)
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- A general approach to the synthesis of β2-amino acid derivatives via highly efficient catalytic asymmetric hydrogenation of α-aminomethylacrylates
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A new strategy was developed for the synthesis of a valuable class of α-aminomethylacrylates via the Baylis-Hillman reaction of different aldehydes with methyl acrylate followed by acetylation of the resulting allylic alcohols and SN2′-type amination of the allylic acetates. Asymmetric hydrogenation of these diverse olefinic precursors using rhodium(Et-Duphos) catalysts provided the corresponding β2-amino acid derivatives with excellent enantioselectivities and exceedingly high reactivities (up to >99.5% ee and S/C=10,000). The first hydrogenation of (Z)-configurated substrates was studied for the synthesis of β2-amino acid derivatives. The high influence of the substrate geometry and steric hindrance on the reactivity and enantioselectivity was also disclosed for this reaction. This protocol provides a highly practical, facile and scalable method for the preparation of optically pure β2- amino acids and their derivatives under mild reaction conditions.
- Guo, Yujuan,Shao, Guang,Li, Lanning,Wu, Wenhao,Li, Ruihong,Li, Jingjing,Song, Jian,Qiu, Liqin,Prashad, Mahavir,Kwong, Fuk Yee
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experimental part
p. 1539 - 1553
(2010/08/22)
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- Asymmetric synthesis of the Roche ester and its derivatives by rhodium-INDOLPHOS-catalyzed hydrogenation
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(S)-3-Hydroxy-2-methylpropionate, known as the Roche ester, and several of its derivatives were successfully synthesized through asymmetric rhodium-catalyzed hydrogenation, using INDOLPHOS (diisopropyl{1-[(S)-3,5-dioxa- 4-phosphacyclohepta[ 2,1-a;3,4-a′]dinaphthalen-4-yl]-3-methyl-2-indolyl} phosphine) as the chiral ligand, in excellent yield and the highest ee reported up to now (TOF over 5500 h-1 at 25°C; up to 98% ee at -40°C).
- Wassenaar, Jeroen,Kuil, Mark,Reek, Joost N. H.
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supporting information; experimental part
p. 1610 - 1614
(2009/07/18)
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- Rhodium-catalyzed enantioselective hydrogenation of β-phthalimide acrylates to synthesis of β2-amino acids
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The enantioselective hydrogenation of β-phthalimide acrylates provides the corresponding chiral β2-amino acids in excellent enantiomeric excess catalyzed by Rh-monophosphorus.
- Huang, Hanmin,Liu, Xiongcai,Deng, Jun,Qiu, Min,Zheng, Zhuo
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p. 3359 - 3362
(2007/10/03)
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- Synthesis of Ring C Modified Sesbanimide Analogues
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D-(+)-Xylose has been converted into C-ring modified analogues of (+)-sesbanimide A, via tricyclic aldehyde 4 as a central intermediate.The synthetic strategy involved the condensation of 4 with appropriate allylstannanes, as C-ring precursors, employing TiCl3(OiPr) as a highly effective electrophilic catalyst. Key Word Index: allylstannanes; titanium trichloride isopropoxyde; stereocontrol; enantioselective
- Vloon, Wilhelmus J.,Bos, Jan C. van den,Koomen, Gerrit-Jan,Pandit, Upendra K.
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p. 8317 - 8328
(2007/10/02)
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