Nevado, Cristina and Charruault, Lise and Michelet, Véronique and Nieto-Oberhuber, Cristina and Munoz-Herranz, Maria and Méndez, María and Rager, Marie-Noëlle and Genêt, Jean-Pierre and Echavarren, Antonio M. (2003) On the Mechanism of Carbohydroxypalladation of Enynes. Additional Insights on the Cyclization of Enynes with Electrophilic Metal Complexes. European Journal of Organic Chemistry, 2003 (4). pp. 706-713. ISSN 1434-193X
Full text not available from this repository.Abstract
Different mechanisms have been proposed for the cyclization of enynes catalyzed by electrophilic metal halides or complexes. We present evidence to indicate that the previously reported “carbohydroxypalladation” and the “hydroxycyclization catalyzed by PtII” are closely related reactions. Thus, palladium complexes formed in situ from PdCl2 and trisulfonated phosphane TPPTS or cyclic phosphite P(OCH2)3CEt as the ligands catalyze the methoxy- or hydroxycyclization of enynes with selectivities similar to those observed with PtII complexes. Deuteration studies indicate that activation of the alkyne by PdII promotes an anti-addition of the alkene.