35 research outputs found

    Difosfani binaftilici P,P'-eterotopici privi di simmetria C<sup>2</sup>. Sintesi e applicazioni in catalisi asimmetrica

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    Recentemente abbiamo portato a compimento con successo la sintesi dei primi difosfani a scheletro binaftilico privi di simmetria C2 (BINAPP') 3 a partire dal ditriflato del binaftolo enantiopuro 1. Questi leganti sono stati preparati con una procedura a più stadi che prevede la sostituzione in sequenza dei due gruppi triflato

    Alkoxy- and hydroxycyclization of enynes catalyzed by Pd(II) and Pt(II) catalysts

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    The development of a novel reaction ideal in terms of atom economy was achieved. The scope of the reaction was evaluated in the presence of Pd and Pt catalysts. The first enantioselective Pt-promoted enyne carboalkoxycyclization was developed in up to 85 % stereoselectivity. This ideal atom-economical reaction afforded the corresponding functionalized five-membered carbo- and heterocycles in good to excellent yields. The use of silver salts combined with (R)-Ph-BINEPINE, a monophosphane atropisomeric ligand, was found to be the best-suited combination for moderate to high enantioselectivities on carbonated and nitrogenated substrates

    C<sub>1</sub>-symmetry bidentate ferrocenyl ligands with pyridine nitrogen donors

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    Following our long standing interest in chiral ligands with nitrogen donors recently we have devised a viable procedure for the preparation of C1-symmetry bidentate ferrocenyl ligands with pyridine nitrogen donors

    Preparazione e applicazioni sintetiche di monoacetali di succinaldeidi

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    Synthetic methods for the preparation of substituted succinaldehyde monoacetals are reviewed and the use of these compounds as intermediates in several synthetic processes is reported

    Studio sulla sintesi dell'acido (R) (S)-2, 3, 3-trimetilbutanoico

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    The authors report a synthetic study on the syntheis of 2, 3, 3-trimethylbutanoic acid which they prepared by ten different synthetic procedures and compare their results with the ones available in the literature on the preparation of the title compound

    Leganti monodentati a chiralità assiale in catalisi asimmetrica

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    La evidente somiglianza strutturale tra il leganti 1-3 e la binaftofosfepina 5, un legante monodentato con un fosforo fortemente elettron donatore e quindi più idoneo all’ottenimento di catalizzatori di idrogenazione di elevata attività catalitica, ci ha spinto ad indagare il comportamento di 5 nell’idrogenazione asimmetrica di olefine con catalizzatori di rodio

    Applicazioni della fenilbinaftofosfepina nella catalisi asimmetrica

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    Nel corso di recenti studi si è dimostrato che la fenilbinaftofosfepina (Ph-BINEPINE), un legante monodentato a chiralità assiale, è l’induttore chirale di gran lunga migliore in una gruppo di due-tre dozzine di altri leganti chirali fosforati mono- e bidentati in alcune reazioni enantioselettive catalizzate da complessi di Pd(II),1 Pt (II)2 e Rh(I)

    Polimeri conduttori e metallopolimeri redox

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    Il nostro gruppo di ricerca è da anni attivo nella sintesi e caratterizzazione elettrochimica di polimeri conduttori a base tiofenica. In particolare la nostra attenzione è rivolta verso materiali costituiti da un backbone di tipo tertiofenico, che consente la polimerizzazione nelle posizioni 2 e 5, e da unità chelanti all’azoto, (terpiridine o fenantroline), che possono consentire la coordinazione con metalli di transizione all’interno del polimero ed incrementarne ulteriormente le proprietà conduttive

    Atropisomeric binaphthalene-core phosphacyclic derivatives in coordination chemistry and homogeneous catalysis

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    Binaphthophospholes and binaphthophosphepines have recently been synthesized. These are the first representatives of a new class of chiral ligands that include within the same structure an endocyclic phosphorus donor, a local C2 symmetry and an axially chiral core. In this review we discuss the synthesis, chemical behaviour and first applications in asymmetric catalysis of these novel derivatives

    Reactions of carbon monoxide with cyclometallated complexes of palladium(II) and platinum(II) derived from a chiral alkylbipyridine ligand

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    The reaction with CO of the six-membered cyclometallated derivatives (L)MCl (2, M = Pd, 3, M = Pt; LH = 6-(1-methylbenzyl)-2,2′-bipyridine), and that of the solvato complexes [(L)M(S)][(BF4], (S = acetone; 4, M = Pd; 5, M = Pt), have been investigated at atmospheric and high pressure (80–90 atm). At atmospheric pressure the complexes 2 and 3 do not react with CO, whereas the cationic derivatives 4 and 5 afford [(L)M(CO)]+ species (6, M = Pd; 7, M = Pt), containing terminal CO ligands. Under higher pressure the palladium complex 2 gives a labile seven-membered acyl derivative, 9, which either affords a benzoquinolizinone, 11, in the presence of ethanol or undergoes reversible decarbonylation when the CO pressure is released. The platinum complex 3 undergoes reversible coordination of a carbonyl ligand, with no insertion of CO into the platinum---carbon bond
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