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
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.