Alternative and complementary approaches to the asymmetric synthesis of C3 substituted NH free or N-substituted isoindolin-1-ones

Complementary synthetic approaches to enantiomerically pure C3 alkylated or arylated NH free or N-substituted isoindolinones have been developed. The key step is elaboration of diversely substituted 2-alkyl- and arylbenzylamines, which can be submitted to a bis-metallation process followed by interception with a carbonylating agent. They can be also converted into N-alkylbromobenzyl-carbamates or into bromobenzyldicarbamates and the assembly of the titled compounds can be readily ensured by reliance upon the Parham cyclization process. (c) 2007 Elsevier Ltd. All rights reserved.