Asymmetric α-Sulfonyl- and α-Phosphoryl-Oxylation of Ketones by a Chiral Hypervalent Iodine(III)
作者:Guillaume Levitre、Audrey Dumoulin、Pascal Retailleau、Armen Panossian、Frédéric R. Leroux、Géraldine Masson
DOI:10.1021/acs.joc.7b01597
日期:2017.11.17
An enantioselective direct oxygenation of propiophenone derivatives mediated by a catalytic or stoichiometric amount of new chiral non-C2-symmetric iodoarenes(III) is reported. The reaction gives an easy entry to optically active α-sulfonyl- and α-phosphoryl oxyketones in respectable yields and enantioselectivities.
Catalytic Enantioselective α-Oxysulfonylation of Ketones Mediated by Iodoarenes
作者:Sabine M. Altermann、Robert D. Richardson、T. Keri Page、Ruth K. Schmidt、Edward Holland、Umal Mohammed、Shauna M. Paradine、Andrew N. French、Christine Richter、A. Masih Bahar、Bernhard Witulski、Thomas Wirth
DOI:10.1002/ejoc.200800741
日期:2008.11
alpha-oxysulfonylation of ketones catalysed by enantioenriched iodoarenes using mCPBA as stoichiometric oxidant is reported to give useful synthetic intermediates in good yield and modest enantioselectivity. We believe this to be the first report of an enantioselective organocatalytic reaction involving hypervalent iodine reagents which should open up a new field for enantioselective organocatalysis of oxidation
A simple synthesis of a library of novel C−N axially chiral iodoarenes is achieved in a three‐step synthesis from commercially available aniline derivatives. C−N axial chiral iodine reagents are rarely investigated in the hypervalent iodine arena. The potential of the novel chiral iodoarenes as organocatalysts for stereoselective oxidative transformations is assessed using the well explored, but challenging
Enantiomerically pure iodoarene (S)-2 and its derivatives (S)-3 to (S)-18 with a spirobiindane scaffold have been synthesized. The evaluation of these new chiral iodoarenes as catalysts in the enantioselective alpha-tosyloxylation of ketones was performed using m-CPBA as a stoichiometric oxidant, and the synthetically useful alpha-tosyloxylated ketones were obtained in up to 58% enantiomeric excess (ee). (C) 2011 Elsevier Ltd. All rights reserved.
Catalytic Enantioselective α-Tosyloxylation of Ketones Using Iodoaryloxazoline Catalysts: Insights on the Stereoinduction Process
作者:Audrey-Anne Guilbault、Benoit Basdevant、Vincent Wanie、Claude Y. Legault
DOI:10.1021/jo302393u
日期:2012.12.21
A family of iodooxazoline catalysts was developed to promote the iodine(III)-mediated alpha-tosyloxylation of ketone derivatives. The alpha-tosyloxy ketones produced are polyvalent chiral synthons. Through this study, we have unearthed a unique mode of stereoinduction from the chiral oxazoline moiety, where the stereogenic center alpha to the oxazoline oxygen atom is significant. Computational chemistry was used to rationalize the stereoinduction process. The catalysts presented promote currently among the best levels of activity and selectivity for this transformation. Evaluation of the scope of the reaction is presented.