The development of efficient methods for the synthesis of complex molecular skeletons containing carbo- and heterocycles has been the subject of extensive study due to their applicability in pharmaceutical research and material science. The use of readily accessible starting materials implemented into domino processes1 represents a fast and efficient way to generate high complexity while preserving atom economy2in just one step.One class of unsaturated substrates which exhibit high potential and variety in reactivity are tethered alkyne moieties.3During our work on carbopalladations starting with carbohydrate derivatives4a and arenes,4bwe discovered a palladium catalyzed domino process consisting of two carbopalladations and a oxypalladation as termination step.A look at the formed domino products revealed a double bond isomerization5 process of the vinlylic palladium species in between the two carbopalladation steps. Whereby, a formal anti-carbopalladation can be observed.For a better understanding of the reaction and to figure out the origin of the anti-connection, mechanistic experiments were conducted. Therefore, we tried to simulate possible domino intermediates as well as substitutions of the second alkyne moiety. Literatur:[1] Tietze, L. F. Chem. Rev. 1996 , 96, 115. [2] Trost, B. M. Science 1991 , 254, 1471. [3] (a) Leibeling, M.; Koester, D. C.; Pawliczek, M.; Schild, S. C.; Werz, D. B. Nat. Chem. Biol. 2010 , 6, 199. (b) Leibeling, M.; Pawliczek, M.; Kratzert, D.; Stalke, D.; Werz, D. B. Org. Lett. 2012 , 14, 346. [3] Wang, C.; Li, X.; Wu, F.; Wan, B. Angew. Chem. Int. Ed. 2011 , 50, 7162. (b) Trost, B. M.; Rudd, M. T. J. Am. Chem. Soc. 2005 , 127, 4763. (c) Singidi, R. R.; Kutney A. M.; Gallucci, J. C.; RajanBabu, T. V. J. Am. Chem. Soc. 2010 , 132, 13078.  [4] (a) Amatore, C.; Bensalem, S.; Ghalem, S.; Jutand, A. J. Organomet. Chem. 2004 , 689, 4642. (b) Abdur Rahman, S. M.; Sonoda, M.; Itahashi, K.; Tobe, Y. Org. Lett. 2003 , 5, 3411.

Pd-catalyzed domino reaction of propargylic diynols to dienol ethers: A formal anticarbopalladation process

248th National Meeting (2014)

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