- Cyclodextrin-based PNN supramolecular assemblies: a new class of pincer-type ligands for aqueous organometallic catalysis
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Water-soluble cyclodextrins (CDs) bearing two nitrogen atoms as metal coordinating sites have been synthesized. An appropriate phosphane could be included within their cavity through the primary face to form self-assembled PNN supramolecular edifices. Once the PNN ligands were coordinated to platinum, the resulting complexes proved to be very effective as catalysts in a domino reaction, where a Pt-catalyzed reduction of nitrobenzene was followed by a Paal-Knorr pyrrole reaction. In the nitrobenzene reduction, the modified CDs acted both as first- and second-sphere ligands. Contrary to an acyclic glucopyranose-based NN ligand unable to interact with a phosphane ligand, the CD-based PNN ligands stabilized the catalytic species in water by supramolecular means. Interestingly, the product and the water-soluble Pt-catalyst could be recovered in two different phases once the reaction was complete.
- Menuel,Bertaut,Monflier,Hapiot
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p. 13504 - 13512
(2015/08/03)
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- One-Pot Synthesis of Substituted Pyrrolidines via Aminomercuration-Demercuration of 1,4- and 1,5-Hexadiene
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The aminomercuratione-demercuration of 1,4- and 1,5-hexadiene yield cis- and trans-2,5-dimethyl-N-arylpyrrolidines via one-pot process.The intermolecular cyclization reaction goes through the corresponding mercurated pyrrolidines; these intermediates were isolated and characterized when the mercuration reaction was completed.The high stereoselectivity observed allows an easy way of synthesis for N-substituted trans-2,5-dimethylpyrrolidines.
- Barluenga, J.,Najera, C.,Yus, M.
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p. 1297 - 1299
(2007/10/02)
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