- Diastereo- And Atroposelective Synthesis of Bridged Biaryls Bearing an Eight-Membered Lactone through an Organocatalytic Cascade
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We present herein an unprecedented stereoselective synthesis of bridged biaryls with defined axial and central chirality from readily available starting materials. This N-heterocyclic carbene-catalyzed method proceeds through propargylic substitution of azolium enolates followed by two-directional cyclization, as supported by DFT calculation. A range of benzofuran/indole-derived bridged biaryls bearing an eight-membered lactone are accessed with uniformly high stereoselectivity (>98:2 dr, mostly >98% ee).
- Lu, Shenci,Ong, Jun-Yang,Yang, Hui,Poh, Si Bei,Liew, Xi,Seow, Chwee San Deborah,Wong, Ming Wah,Zhao, Yu
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supporting information
p. 17062 - 17067
(2019/11/03)
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- Preparation method of 2,2'-dihydroxy diphenyl ketone compound
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The invention relates to a preparation method of a 2,2'-dihydroxy diphenyl ketone compound. The method belongs to the technical field of ketone acyclic compound synthesis, and comprises the steps of adopting 5-alkyl-3-[5-alkyl-2-hydroxycyclohexyl phenyl ketone]benzofuran-2-(3 hydrogen)-ketone as a raw material, dissolving in a solvent, adding an anhydrous alkali catalyst, feeding oxygen or air, and carrying out oxidation reaction. The preparation method provided by the invention is applied to preparing the dihydroxy diphenyl ketone compound and has the advantages of concise steps, green synthesis without pollution, high yield and the like.
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Paragraph 0111; 0120; 0123; 0128; 0135
(2018/09/11)
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- Preparation method of 2,2'-dyhydroxy benzophenone compound
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The invention relates to a preparation method of a 2,2'-dyhydroxy benzophenone compound, and belongs to the technical field of synthesis of ketone acyclic compounds. 2,2-di(2-hydroxy-5-alkylphenyl)methyl acetate is taken as a raw material, an anhydrous base catalyst is added after the raw material is dissolved in a solvent, oxygen or air is injected to conduct an oxidation reaction, and the compound is prepared. The preparation method is applied to preparation of the dyhydroxy benzophenone compound, and has the advantages that the steps are easy and simple, the synthesis process is green and free of pollution, and the yield is high.
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Paragraph 0087; 0088; 0098; 0103; 0104; 0111; 0112
(2018/09/11)
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- Complete chiral induction from enantiopure 1,2-diamines to benzophenone-based achiral bisphosphane ligands in noyori-type RuII catalysts
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We report the design and synthesis of a novel class of RuII catalysts (3) composed of achiral benzophenone-based bisphosphane ligands and enantiopure 1,2-diamines for the asymmetric hydrogenation of aryl ketones. The developed catalysts show excellent enantioselectivities (up to 97 % ee) and activities (up to S/C = 10,000) in the hydrogenation of a variety of aromatic ketones. Complete chiral induction from the enantiopure 1,2-diamine to the achiral bisphosphane ligand was observed. The coordination of the C=O moiety in 3 to the cationic RuII center is considered to be of key importance in providing a higher thermodynamic and kinetic rotation barrier for the flexible bisphosphane ligand, resulting in the preferential formation of only one diastereomer, and thus explaining the high enantioselectivity of the catalyst. Wiley-VCH Verlag GmbH & Co. KGaA, 2006.
- Jing, Qing,Sandoval, Christian A.,Wang, Zheng,Ding, Kuiling
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p. 3606 - 3616
(2012/12/23)
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- Synthesis and Inclusion Properties of Carbonyl-Bridged Analogs of Acyclic p-t-Butylphenol-Formaldehyde Oligomers
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A series of compounds in which a part or all of the methylene bridges of acyclic p-t-butylphenol-formaldehyde oligomers are replaced by C=O bridge(s) has been synthesized.The carbonyl-bridged tetramers, except for that with no methylene bridge, formed crystalline host-guest complexes with various organic compounds; those with two C=O bridges were superior regarding complexation, regardless of the position of the bridges.Exclusive guest selectivity of the tetramer with one terminal C=O bridge was observed for benzene and its methyl derivatives in a two-component system.The fully carbonyl-bridged dimer, trimer, tetramer, and pentamer had no complexing-capability.The thermal stability of benzene complexes (host : guest = 2 : 1) of the tetramers with one C=O bridge, as estimated from their thermal dissociation rates, are remarkably lower than that of the parent tetramer.Oximes derived from the tetramers with one C=O bridge were much more effective than the corresponding carbonyl-bridged ones regarding their complex-forming capability.
- Ohba, Yoshihiro,Irie, Keisaku,Zhang, Fu Sheng,Sone, Tyo
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p. 828 - 835
(2007/10/02)
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