- The Ligand Free Palladium(II)-Catalyzed Regioselective 1,2-Addition of Enol Silanes to Quinones to Access 4-Hydroxy-4-(2-oxo-2-arylethyl)cyclohexadien-1-ones and Synthetic Applications
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In contrast to the conventional 1,4-addition process, regioselective 1,2-addition of silyl enol ethers to quinones can now be achieved via a palladium(II) enolate pathway that provides access to 4-hydroxy-4-(2-oxo-2-arylethyl)cyclohexa-2,5-dien-1-one derivatives. This quinone alkylation protocol proceeds under mild reaction conditions at ambient temperature under open air and does not require either an external ligand for the palladium or the use of a base. Additionally, the cyclohexadienone products have been exploited as synthetic precursors for the construction of fused heteroaryl systems.
- Polimera, Subba Rao,A. M. Subbaiah, Murugaiah,Ilangovan, Andivelu
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p. 14356 - 14370
(2021/10/12)
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- Selective Metal-Free Deoxygenation of Unsymmetrical 1,2-Dicarbonyl Compounds by Chlorotrimethylsilane and Sodium Iodide
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For the first time, the combination of chlorotrimethylsilane with NaI is used as a selective reducting system toward 1,2-diketones. This combination is successfully evaluated with several unsymmetrically benzil derivatives, which are reduced in good yield
- Yuan, Ling-Zhi,Renko, Dolor,Khelifi, Ilhem,Provot, Olivier,Brion, Jean-Daniel,Hamze, Abdallah,Alami, Mouad
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supporting information
p. 3238 - 3241
(2016/07/14)
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- Cu-Catalyzed Stereoselective γ-Alkylation of Enones
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A general regio- and stereoselective γ-C-C bond formation is achieved using α-halocarbonyl compounds and dienol ethers via Cu(II) catalysis. This method constitutes a novel approach to the challenging 1,6-dioxygenation motif. A range of γ-substituted enones, including many bearing all-carbon quaternary centers, are available through a simple protocol under mild reaction conditions with superb functional group compatibility. Excellent stereoinduction is observed providing controlled access to challenging stereochemical arrays.
- Chen, Xiaohong,Liu, Xiaoguang,Mohr, Justin T.
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supporting information
p. 6364 - 6367
(2016/06/09)
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- Palladium catalyzed addition of arylboronic acid or indole to nitriles: Synthesis of aryl ketones
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Aryl ketones can be synthesized conveniently by a palladium catalyzed addition of arylboronic acid to nitriles in aqueous triflic acid. This catalytic system was extended to the addition of unprotected indoles to nitriles under a slightly modified condition to produce 3-acyl indoles in good yields.
- Das, Tuluma,Chakraborty, Amarnath,Sarkar, Amitabha
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supporting information
p. 7198 - 7202
(2015/01/09)
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- QUINOLINE AND QUINOXALINE DERIVATIVES AS INHIBITORS OF KINASE ENZYMATIC ACTIVITY
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Compounds of formula (IA) or (IB), are inhibitors of aurora kinase activity: Formula (IA), (IB) wherein -L1Y1-[CH2]z- is a linker radical wherein Y1, L1 and z are as defined in the claims; R6 is C1-C4alkoxy, hydrogen or halo; W represents a bond, -CH2-, -O-, -S-, -S(=O)2-, or -NR5- where R5 is hydrogen or C1-C4 alkyl; Q is =N-, =CH- or =C(X1)- wherein X1 is cyano, cyclopropyl or halo; linker radicals L2 are as defined in the claims; R is a radical of formula (X) or (Y): wherein R1 is a carboxylic acid group (-COOH), or an ester group which is hydrolysable by one or more intracellular carboxylesterase enzymes to a carboxylic acid group; R4 is hydrogen; or optionally substituted C1-C6 alkyl, C3-C7 cycloalkyl, aryl, aryl(C1-C6 alkyl)-, heteroaryl, heteroaryl(C1-C6 alkyl)-, -(C=O)R3, -(C=O)OR3, or -(C=O)NR3 wherein R3 is hydrogen or optionally substituted (C1-C6)alkyl, C3-C7 cycloalkyl, aryl, aryl(C1-C6 alkyl)-, heteroaryl, or heteroaryl(C1-C6 alkyl)-; R41 is hydrogen or optionally substituted C1-C6 alkyl; and D is a monocyclic heterocyclic ring of 5 or 6 ring atoms.
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- Effect of Ring Substitution on the Photochemistry of α-(Aryloxy)acetophenones
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The photochemistry of a series of 10 α-(aryloxy)acetophenones has been examined by quantum yield, product studies, and laser flash photolysis techniques.Triplet decay involves a competition of β-cleavage with intramolecular quenching by the β-aryl group, the latter being favored in all systems.Typical triplet lifetimes at room temperature range from 60 to 260 ps and are rather insensitive to the substitution pattern. β-Cleavage rate constants range between 1*107 and 3*109 s-1 and are strongly favored by electron releasing substituents, such as 4-methoxy.The determination of true quantum yields of β-cleavage requires the addition of thiophenol as a radical trap to prevent the efficient back reaction that takes place otherwise; under these conditions quantum yields range from 10-3 to 0.14, the highest value being obtained for the 4-methoxy and 4-hydroxy derivatives.
- Netto-Ferreira, J.C.,Avellar, I.G.J.,Scaiano, J.C.
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- THE TIN(II) ENOLATE ADDITION REACTIONS TO α,β-UNSATURATED KETONES AND QUINONES
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The reaction of tin(II) enolates with various α,β-unsaturated carbonyl compounds is examined.When TMSCl is added as an activator of the α,β-unsaturated ketones, the Michael addition reaction proceeds smoothly to give the corresponding 1,4-adduct in good y
- Mukaiyama, Teruaki,Iwasawa, Nobuharu,Yura, Takeshi,Clark, R. S. J.
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p. 5003 - 5018
(2007/10/02)
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- A Convenient Preparation of α-(p-Hydroxy- or p-Aminophenyl) Carbonyl Compounds. Addition-Reduction Reaction of Tin(II) Enolate with p-Benzoquinone and Its Mono-N-tosylimino Derivative
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Tin(II) enolates react with p-benzoquinone and its mono-N-tosylimino derivative to give 1,2-adducts in good yield.These can be reduced in situ to α-(p-hydroxy- or p-aminophenyl) carbonyl derivatives by addition of dichloromethylsilane and dimethylaminopyr
- Mukaiyama, Teruaki,Clark, Richard S. J.,Iwasawa, Nobuharu
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p. 479 - 482
(2007/10/02)
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