- Cyclohexyl-Fused, Spirobiindane-Derived, Phosphine-Catalyzed Synthesis of Tricyclic ?3-Lactams and Kinetic Resolution of ?3-Substituted Allenoates
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A C2-symmetric chiral phosphine catalyst, NUSIOC-Phos, which can be easily derived from cyclohexyl-fused spirobiindane, was introduced. A highly enantioselective domino process involving pyrrolidine-2,3-diones and γ-substituted allenoates catalyzed by NUSIOC-Phos has been disclosed. Diastereospecific tricyclic γ-lactams containing five contiguous stereogenic centers were obtained in high yields and with nearly perfect enantioselectivities. A kinetic resolution process of racemic γ-substituted allenoates was developed for the generation of optically enriched chiral allenoates.
- Wu, Mingyue,Han, Zhaobin,Li, Kaizhi,Wu, Ji'En,Ding, Kuiling,Lu, Yixin
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p. 16362 - 16373
(2019/10/16)
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- Preparation method for indanone compound
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The invention especially relates to a preparation method for an indanone compound, belonging to the field of organic synthesis. The preparation method for the indanone compounds comprises the following steps: 1) subjecting a compound as shown in a formula I and a compound as shown in a formula II to a condensation reaction so as to prepare a compound as shown in a formula III; 2) subjecting the compound as shown in the formula III to hydrolysis in the presence of alkali so as to prepare a compound as shown in a formula IV; and 3) carrying out acylation and ring closure on the compound as shownin the formula IV so as to prepare the as shown in a formula V. Compared with the prior art, the preparation method for the indanone compound in the invention has the advantages of low raw material cost, simple operation, low production of waste water, waste gas and industrial residues, high yield and the like, and is more suitable for industrial production; and compared with various traditionalpreparation methods for the indanone compound, the preparation method of the invention has obvious advantages and shows good industrialization prospects.
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- Regioselective intramolecular oxidation of phenols and anisoles by dioxiranes generated in situ
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A novel method for regioselective oxidation of phenols and anisoles has been developed in which dioxiranes, generated in situ from ketones and Ozone, oxidize phenol derivatives in an intramolecular fashion. A series of ketones with electron-withdrawing groups, such as CF3, COOMe, and CH2Cl, were attached to phenols, anisoles, or aryl rings via a C2 or C3 methylene linker. In a homogeneous solvent system of CH3CN and H2O, oxidation of phenol derivatives 1-10 afforded spiro 2-hydroxydienones in 24-55% yields regardless of the presence of other substituents (ortho Me, meta Me or Br) on the aryl ring and the length of the linker. Experimental evidences were provided to support the mechanism that involves a regioselective π bond epoxidation of aryl rings followed by epoxide rearrangement and hemiketal formation.
- Yang, Dan,Wong, Man-Kin,Yan, Zheng
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p. 4179 - 4184
(2007/10/03)
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- An N.M.R. Investigation of the Mills-Nixon Effect
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The 4J coupling constant, previously established as a probe of bond order, was used to examine the bond orders in a series of ortho-bridged compounds: benzocyclopropene, 1,2-dihydrobenzocyclobutene, indan and tetralin.No evidence for sterically induced bond fixation (i.e. the Mills-Nixon effect) was found, but some evidence for electronic distortion in the corresponding benzylic ketones was observed.The experimental results are in accord with SCF/MO calculations.
- Collins, Michael J.,Gready, Jill E.,Sternhell, Sever,Tansey, Charles W.
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p. 1547 - 1557
(2007/10/02)
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