- A chelating β-diketonate/phenoxide ligand and its coordination behavior toward titanium and scandium
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Dibenzoylmethane derivatives with one (L1H2) or both (L2H3, L3H3) benzenes linked at their ortho positions to 4,6-di-tert-butylphenol moieties by two-carbon linkers have been synthesized. The mono-β-diketone-monophenol ligand L 1H2 is metalated by titanium alkoxides to form the homoleptic complex (L1)2Ti and heteroleptic complexes (L1)Ti([OCH2CH2]2NR) (R = H, CH 3), and reacts with Cp3Sc to form CpSc(L1). These are the first examples of complexes of a β-diketonate ligand which is further chelating to a single metal center. Crystallographic analysis of (L1)2Ti indicates that the 10-membered ring allows chelation of the phenoxide with little strain, and both fac and mer geometries are accessible in solution. Protonolysis of the second cyclopentadienyl ring of Cp3Sc appears to take place by an indirect, Cp3Sc- catalyzed pathway. The Royal Society of Chemistry 2006.
- Schroeder, Tobias,Ugrinova, Vesela,Noll, Bruce C.,Brown, Seth N.
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p. 1030 - 1040
(2007/10/03)
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- Dialkyl phosphonates and tetraalkyl bis(phosphonate)s from the decomposition of quasi-phosphonium ylidic phosphonates in aqueous conditions
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The reaction of dimethyl benzoylphosphonates 1 (X = 2-halogen or 2-CF3O) with trialkyl phosphite leads to the formation of carbene intermediates 3 which are trapped by trialkyl phosphite to give the corresponding ylidic phosphonates 4. In acidi
- Griffiths, D. Vaughan,Karim, Khalku,Harris, Jayne E.
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p. 2539 - 2544
(2007/10/03)
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- Fungicides
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This invention relates to derivatives of acrylic acid useful as fungicides, to processes for preparing them, to fungicidal compositions containing them, and to methods of combating fungi, especially fungal infections in plants, using them.
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- Vinyl Azides in Heterocyclic Synthesis. Part 10. Synthesis of the Isoindolobenzazepine Alkaloid Lennoxamine
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A total synthesis of the isoindolobenzazepine alkaloid lennoxamine (1), by a route involving vinyl azide chemistry, is described.Model studies on the azidocinnamates (12) and (13) revealed a striking difference between the (E)- and (Z)-isomers; whereas the (Z)-isomer (12) gave largely the 1-benzylisoquinoline (15) on decomposition, the (E)-isomer (13) gave the 2-aryl-3-benzazepine (14) as the major product.Consequently, in the lennoxamine synthesis, the azidocinnamate (26) bearing the (E)-alkenyl side chain, prepared from 6-bromopiperonal via the (E)-stilbene aldehyde (25) (Scheme 4), was decomposed to give the key 2-aryl-3-benzazepin e (27).Reduction of the double bonds in (27) was accompanied by cyclisation to the tetrahydroisoindolobenzazepine (30), which was converted into lennoxamine (1) by reduction of the ester group to an aldehyde, and decarbonylation.
- Moody, Christopher J.,Warrellow, Graham J.
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p. 2929 - 2936
(2007/10/02)
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- Fungicides
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Compounds of formula: ψψ and stereoisomers thereof, wherein X, Y and Z, which may be the same or different, are hydrogen or halogen atoms, optionally substituted alkyl, optionally substituted alkenyl, optionally substituted aryl, optionally substituted alkynyl, haloalkyl, alkoxy, haloalkoxy, optionally substituted aryloxy, optionally substituted arylalkoxy, optionally substituted acyloxy, optionally substituted amino, optionally substituted arylazo, acylamino, nitro, nitrile, -CO2R3, -CONR4R5, -COR6, -CR7=NR8, or -N=CR9R10 groups; or the groups X and Y, when they are in adjacent positions on the phenyl ring, may join to form a fused ring, either aromatic or aliphatic, optionally containing one or more heteroatoms; and R1, Ry, R3, R4, R5, R6, R7, R8, R9 and R10, which may be the same or different, are hydrogen atoms or alkyl, cycloalkyl, alkenyl, alkynyl, optionally substituted aryl, optionally substituted aralkyl, or cycloalkylalkyl groups; and metal complexes thereof.ψ
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