<i>anti</i>-Carbopalladation Cascades of\nInternal Alkynes Terminated by Intermolecular Suzuki and Sonogashira\nReactions

In this report, we describe Pd-catalyzed cascade reactions\nin which\ntwo internal alkynes undergo two <i>trans</i>-carbocarbonation\nreactions, leading to new carbon–carbon bonds across the emerging\ndouble bonds. The resulting vinyl Pd intermediate being obtained after\ntwo carbopalladations is involved in either terminating Suzuki or\nSonogashira reactions leading to either highly substituted butadienes\nor hexadienynes. A variety of different precursors as well as boronic\nacids and alkynes, respectively, were employed, yielding a broad spectrum\nof the corresponding products in yields of up to 82%.