Heterogeneous platinum catalytic aerobic oxidation of cyclopentane-1,2-diols to cyclopentane-1,2-diones
摘要:
A method for the aerobic oxidation of cyclopentane-1,2-diols to the corresponding diketones over a commercial heterogeneous Pt/C catalyst is described. Unsubstituted and 3- or 4-substituted cyclopentane-1,2-diols are oxidized to 1,2-dicarbonyl compounds in good yields under the reported optimized reaction conditions (atmospheric air, 1 mol % of catalyst, 1 equiv of LiOH, aqueous solvents and 60 degrees C temperature). The method is applicable for producing cyclopentane-1,2-diketones in a scalable manner. (C) 2014 Elsevier Ltd. All rights reserved.
Synthetic and Theoretical Studies of Cyclobuta[1,2:3,4]dicyclopentene. Organocobalt Intermediates in the Construction of the Unsaturated Carbon Skeleton and Their Transformation into Novel Cobaltacyclic Complexes by C−C Insertion
作者:Andrew G. Myers、Miki Sogi、Michael A. Lewis、Stephen P. Arvedson
DOI:10.1021/jo030368p
日期:2004.4.1
kcal/mol higher in energy than the isomeric hydrocarbon 1,6-didehydro[10]annulene (2), a molecule known to isomerize to 1,5-didehydronaphthalene (4) above −50 °C. Calculated enthalpic changes of homodesmotic reactions support the notion that 1 is an aromatic molecule with a resonance stabilization energy (RSE) about half to two-thirds that of benzene on a per-molecule basis. Investigations of potential
yields and excellent enantioselectivity. An asymmetric organocatalytic Michael addition–cyclization cascade reaction has been developed using cyclopentane-1,2-dione as a Michael donor and α,β-unsaturated aldehydes as Michael acceptors. Bicyclic hemiacetals were obtained in excellent yields and enantioselectivities. On the basis of the results, a one-potreaction has been developed to obtain chiral 3-substituted
Abstract Organocatalytic Michael additions of cyclopentane-1,2-dione to different nitroolefins have been investigated. Cyclopentane-1,2-dione undergoes an organocatalytic reaction with substituted nitroolefins giving 3-substituted products in good to high yields (48–97%) and good stereoselectivity (up to 76% ee). Organocatalytic Michael additions of cyclopentane-1,2-dione to different nitroolefins have
Anhydrous Iron(III) Chloride Dispersed on Silica Gel; III.<sup>1,2</sup>A Convenient and Mild Reagent for Deacetalization in Dry Medium
作者:Antoine Fadel、Ramdane Yefsah、Jacques Salaün
DOI:10.1055/s-1987-27833
日期:——
Acetals of various structures are conveniently cleaved under mild conditions by anhydrous iron(III) chloride dispersed silica gel in the absence of any solvent.
Asymmetric Synthesis of Chiral 1,3-Diaminopropanols: Bisoxazolidine-Catalyzed CC Bond Formation with α-Keto Amides
作者:Hanhui Xu、Christian Wolf
DOI:10.1002/anie.201105778
日期:2011.12.16
Three high‐yielding steps lead to the formation of chiral 1,3‐diaminopropanols from aliphatic and aromatic α‐keto amides. In this approach, a nitroaldol reaction, which is catalyzed by Cu(SO2CF3)2 and the bisoxazolidine ligand L1, is followed by two mild reduction reactions (see scheme). Laborious protection and deprotection steps can be avoided by using this method.