Heterocyclic derivatives containing phenethylamine units have shown important dopaminergic properties. In particular, seven-membered 3-benzazepines remain as one of the most reliable structural scaffold in terms of the affinity and selectivity against the D1 receptor of mammalian brains. Metal-mediated intramolecular hydroamin(d)ations of alkynylamin(d)es have been employed as one of the typical pathways for their preparation. However, no 7-endo dig cyclization of terminal o-(alkynyl)phenthylamines to 3-benzazepines has been described. Based on our recently developed Os-catalyzed cyclization of terminal bis-homopropargylic alcohols, we now report the novel Os-catalyzed 7-endo dig cyclization of terminal o-(alkynyl)phenethylamines 1 to 3-benzazepines 2 via the formation of new osmacyclopropene intermediates I and II, which have been characterized by X-Ray analysis (L= PiPr3).

Resumen del póster presentado a la XXXV Reunión Bienal de la Real Sociedad Española de Química celebrada en A Coruña del 19 al 23 de julio de 2015.-- Tambien presentado al Organometallic Chemistry Directed Towards Organic Synthesis (OMCOS) IUPAC International Symposium, celebrado en Sitges-Barcelona (España) del 28 de junio al 2 de julio de 2015.

This work was supported by MICINN (project CTQ2011-28258 and ORFEO-CINQA CTQ2014-51912-REDC), Xunta de Galicia and European Development Fund (projects GRC2014/032 and EM 2012/051). A.A-P. thanks MINECO (Spain) for a FPI fellowship (BES-2012-054798).

Peer Reviewed