Dearomatizing anionic cyclization of substituted N-cumyl-N-benzyl- benzamides on treatment with LDA: synthesis of partially saturated substituted isoindolones
On treatment with LDA, substituted N-benzylbenzamides (including those bearing electron-withdrawing, electron-donating, or conjugating groups) become lithiated and cyclize to give, after aqueous quench, a range of partially saturated isoindolones as single regio- and stereoisomers. In general, the isoindolones resist rearomatization. Reaction of N-cumyl-N-benzylbenzamides leads to cyclized products which may be deprotected to give N-unsubstituted isoindolones.
Clayden
J
Department of Chemistry, University of Manchester, Oxford Road, Manchester M13 9PL, U.K., and Aventis CropScience SA, Centre de Recherche de La Dargoire, 14-20 rue Pierre Baizet - BP 9163, 69263 Lyon Cedex 09, France.
Menet
CJ
Mansfield
DJ