High-yielding synthesis of Nefopam analogues (functionalized benzoxazocines) by sequential one-pot cascade operations

Abstract

An efficient amine-/ruthenium-catalyzed three-step process for the synthesis of Nefopam analogues was achieved through combinations of cascade enamine amination/iso-aromatization/allylation and diene or enyne metathesis as key steps starting from functionalized Hagemann's esters. In this communication, we discovered the application of ruthenium-catalysis on olefins containing free amines without in situ formation of salts. © 2009 The Royal Society of Chemistry.