Pd-catalyzed dehydrogenative annulation approach for the efficient synthesis of phenanthridinones
作者:Xinyao Li、Jun Pan、Song Song、Ning Jiao
DOI:10.1039/c6sc01148a
日期:——
annulation of aryl iodides and aryl carbamic chlorides for the efficientsynthesis of phenanthridinone derivatives was developed. Simple aryl iodides and carbamic chlorides readily made from various anilines, a broad substrate scope with hetero/polycycles, as well as high-value products, make this direct dehydrogenative annulation approach very practical and attractive.
Abstract This paper describes the development of a palladium-catalyzed decarbonylative C–N couplingreaction that transforms arylcarbamoyl chlorides into tetrasubstituted ureas under a nitrogen atmosphere. A broad range of functional groups are compatible with this reaction, and diverse urea derivatives can be obtained with good to high yields. Graphical Abstract
An iridium complex successfully catalyzed the annulation of various N-arylcarbamoyl chlorides with internal alkynes to afford 2-quinolones in good to excellent yields. The present reaction is widely applicable to substrates with various functionalities. An amide-iridacycle complex was isolated, and it is likely that such an iridacycle species is a key intermediate in the catalytic reaction.
α-Quaternary Proline Derivatives by Intramolecular Diastereoselective Arylation of <i>N</i>-Carboxamido Proline Ester Enolates
作者:Julien Maury、Jonathan Clayden
DOI:10.1021/acs.joc.5b01912
日期:2015.11.6
Pyrrolidine-2-carboxylate esters substituted in the 3-, 4- or 5-positions were converted to their N'-aryl urea derivatives. Deprotonation at the 2-position to form a potassium enolate led to migration of the N'-aryl substituent to the 2 position of the pyrrolidine ring, followed by cyclization of the resulting urea to give bicyclic alpha-aryl hydantoin derivatives of substituted prolines. Depending on the substitution pattern of the starting material, high diastereoselectivity was observed in the aryl migration, allowing formation of the products in enantiomerically enriched form, despite the intermediacy of a planar enolate. The hydrolysis of the bicyclic hydantoins under basic conditions gave a range of enantiopure and enantioenriched quaternary alpha-aryl proline derivatives.