On October 27, 2014, Klitzke, Joice S.; Roisnel, Thierry; Kirillov, Evgeny; Casagrande, Osvaldo de L. Jr.; Carpentier, Jean-Francois published an article.Application In Synthesis of (R)-Methyl 3-hydroxybutanoate The title of the article was Discrete O-Lactate and β-Alkoxybutyrate Aluminum Pyridine-Bis(naphtholate) Complexes: Models for Mechanistic Investigations in the Ring-Opening Polymerization of Lactides and β-Lactones. And the article contained the following:
Me aluminum(III) complexes {ONOSiR3}AlMe (SiR3 = SiPh3 (2a), SiMe2tBu (2b)) were synthesized by reaction of AlMe3 with pyridine-bis(naphthol) proligands {ONOSiR3}H2 (1a,b) having bulky o-SiR3 substituents on the naphthol groups. Complexes 2a,b were converted into the Al isopropoxide, O-lactate, and β-alkoxybutyrate complexes {ONOSiR3}AlOR’ (R’ = iPr (3a), (S)-CH(Me)CO2iPr (4a,b), (R)-CH(Me)CH2CO2Me (5a), rac-CH(CF3)CH2CO2Et (6a)) by reaction with the corresponding alc. and α- and β-hydroxy esters R’OH. C-H···π close contacts between the SiPh3 Ph groups and hydrogens of the methine, methylene, and alkyl ester groups were evidenced by x-ray diffraction studies (for 2a and 4a-6a) and by solution NMR. In contrast to the case for (S)-4b, (S)-4a interacts reversibly with racemic lactide (rac-LA) in toluene-d8 at 20°, discriminating the L and D monomers, yet without forming isolable six-coordinated adducts. NMR monitoring of the reaction of (S)-4a with L-LA in CD2Cl2 at room temperature allowed identifying the propagation product 7a, as a result of propagation being faster than insertion. The same propagating species formed upon reaction of (S)-4a with L-LA in toluene-d8 at 80°. Conversely, the reaction of (R)-5a and L-LA in CD2Cl2 eventually allowed catching the very first insertion product 8a. These observations imply that insertion of LA proceeds more easily into a six-membered Al β-alkoxybutyrate species than into a five-membered Al O-lactate species. The experimental process involved the reaction of (R)-Methyl 3-hydroxybutanoate(cas: 3976-69-0).Application In Synthesis of (R)-Methyl 3-hydroxybutanoate
The Article related to lactate beta alkoxybutyrate aluminum pyridine naphtholate preparation crystal structure, mechanistic ring opening polymerization lactide beta lactone aluminum pyridinenaphtholate and other aspects.Application In Synthesis of (R)-Methyl 3-hydroxybutanoate
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