Open Collections

Oxidative cyclization of phenolic N-acyl sulfonamides

University of British Columbia

The oxidative activation of appropriately substituted phenols with a hypervalent iodine reagent, in the presence of suitable nitrogen nucleophiles, results in formation of 2- or 4-amidodienones. The process is described as the oxidative amidation of phenols. The dienones thus produced are useful building blocks for the synthesis of alkaloids. The nitrogen nucleophile may be an oxazoline, a sulfonamide or phosphoramide (intramolecular reactions), or a nitrile (bimolecular reaction), but not a carboxamide. This is because carboxamides express Onucleophilicity toward oxidatively activated phenols, resulting in formation of iminolactones, which are readily hydrolyzed to lactones upon workup. This present thesis describes efforts to extend oxidative amidation chemistry to carboxamides. The behavior of phenolic N-acyl sulfonamides was thus explored. The product obtained upon oxidative cyclization of these substrates proved to be dependent upon their structure. In many cases, N-sulfonyl iminolactones were thus obtained. These heretofore undocumented products proved to be surprisingly stable and resistant to hydrolysis.

Text

2017-04-20

Attribution-NonCommercial-NoDerivatives 4.0 International

http://hdl.handle.net/2429/61303

Chemistry

University of British Columbia

UBCV

http://creativecommons.org/licenses/by-nc-nd/4.0/