Dehydrative Cyclization of Alkynals: Vinylidene Complexes with the Cβ Incorporated into Unsaturated Five- or Six-Membered Rings

A nice ring: The title compounds are easily prepared by dehydrative cyclization of terminal alkynals in the presence of osmium, iridium, and rhodium precursors (see scheme). Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Financial support from the MICINN of Spain (project numbers CTQ2008-00810 and CTQ2008-06557), and the Consolider Ingenio 2010 (CSD2007-00006), The Diputacion General de Aragón (E35), Xunta de Galicia, and the European Regional Development Fund (2007/XA084 and INCITE08PXIB 209024PR), and the European Social Fund is acknowledged. M.B. and L.E. thank the Spanish MICINN and Fundación Fundayacucho (Venezuela), respectively, for predoctoral grants.