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Over the past two decades, spectacular progress has been achieved in the field of Metal/Ligand cooperative catalysis using pincer complexes. In particular, Milstein discovered an original aromatization/dearomatization process in pyridine-based pincer complexes that has been applied to a wide range of efficient transformations [1] involving transition metals from groups 7-9. Comparatively, very few examples of Metal/Ligand cooperative catalysis with metals of group 10 have been reported.We have described original indenediide Pd(II) and Pt(II) pincer complexes combining an electrophilic metal center and an electron-rich ligand backbone [2]. This indenediide pincer ligand shows a non-innocent behavior that has been applied in the catalytic intramolecular addition of carboxylic acids/amides to alkynes in the absence of external base. An important breakthrough was obtained for the formation of 5-, 6- and even 7-membered ring lactones/lactams including the first efficient preparation of ε-methylene caprolactones/lactams [3]. A remarkable behavior has also been evidenced in the construction of the oxazolididone motif from propargylamines using CO2 as C1 building block. The results show that the indenediide Pd(II) pincer complexes perform very efficiently, with a broad scope of substrates in terms of alkyne substitution and class of amine [4]. We are currently seeking to expand the applications of these complexes to other valuable transformations, in particular cyclizations involving C-C bond creation, and to other kinds of cooperativity, here with Lewis acids
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