On January 13, 2014, Klitzke, Joice S.; Roisnel, Thierry; Kirillov, Evgeny; de L. Casagrande, Osvaldo Jr.; Carpentier, Jean-Francois published an article.Product Details of 3976-69-0 The title of the article was Yttrium- and Aluminum-Bis(phenolate)pyridine Complexes: Catalysts and Model Compounds of the Intermediates for the Stereoselective Ring-Opening Polymerization of Racemic Lactide and β-Butyrolactone. And the article contained the following:
Yttrium and aluminum complexes of an original pyridine-bis-(phenolate) ligand were prepared Reactions of {ONOMe,Cumyl}-Y-[N-(SiHMe2)2](THF)(Et2O) (1) with 1 equiv of Me-(R)-3-hydroxybutyrate and Me (S,S)-lactyllactate afforded resp. {ONOMe,Cumyl}-Y-((R)-OCH-Me-CH2COOMe) (2) and {ONOMe,Cumyl}-Y-((S,S)-OCH-Me-CO2CH-Me-CO2Me) (3), which are rare models of the active species in the ring-opening polymerization (ROP) of β-butyrolactone (BBL) and lactide (LA), resp. 13C NMR data for 2 and 3 indicate that, in solution, the carbonyl groups coordinate onto the yttrium centers, forming mononuclear species with six- and five-membered cycles, resp. The aluminum compounds {ONOMe,Cumyl}-Al-(iPr-(S)-lactate) (5), {ONOMe,Cumyl}-Al-((R)-OCH-Me-CH2COOCH3) (6), and {ONOMe,Cumyl}-Al-((rac)-OCH-(CF3)-CH2CO2C2H5) (7) were prepared analogously from the parent Me complex {ONOMe,Cumyl}-AlMe (4). NMR data and the solid-state structure of 6 confirm the coordination of the carbonyl group. Yttrium compounds 1 and 2 are active initiators for the ROP of racemic LA and BBL. Their performances (activity, control of the mol. weights, tacticity) are much affected by the nature of the solvent or by the addition of just a few equivalent of pyridine. Optimal conditions are quite contrasted for the ROP of rac-LA and rac-BBL, highlighting fundamental differences between these two monomers. In the best cases, highly heterotactic PLAs (Pr up to 0.96) and syndiotactic-enriched PHB (Pr up to 0.86), with good control over the mol. weights, were obtained. The experimental process involved the reaction of (R)-Methyl 3-hydroxybutanoate(cas: 3976-69-0).Product Details of 3976-69-0
The Article related to yttrium aluminum pyridinebisphenolato hydroxybutyrate lactyllactate complex preparation crystal structure, lactide butyrolactone polymerization yttrium aluminum pyridinebisphenolato hydroxybutyrate complex catalyst and other aspects.Product Details of 3976-69-0
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