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Modification of aluminium alkoxides with dialkylmalonates.

Lichtenberger R, Baumann SO, Bendova M, Puchberger M, Schubert U - Monatsh. Chem. (2010)

Bottom Line: Al(malonate)3 (malonate = dimethyl, diethyl, di-iso-propyl and di-tert-butyl malonate), Al2(OiPr)4(malonate)2 (malonate = di-iso-propyl and di-tert-butyl malonate), Al2(OiPr)2(di-iso-propylmalonate)4 and Al3(OH)(OEt)3(diethylmalonate)5.An Al2(OiPr)2(dialkylmalonate)4 derivative was only obtained by disproportionation of Al2(OiPr)4(di-iso-propylmalonate)2, but not by reaction of Al(OiPr)3 with dialkylmalonates in the corresponding molar ratio.Reactions of Al(OtBu)3 only resulted in Al(malonate)3 derivatives, but no transesterification was observed, contrary to the reaction of Al(OiPr)3 with dimethyl or diethyl malonate.

View Article: PubMed Central - PubMed

Affiliation: Institute of Materials Chemistry, Vienna University of Technology, Vienna, Austria.

ABSTRACT

Abstract: Depending on the reaction conditions, different aluminium dialkylmalonate derivatives were obtained by reaction of aluminium alkoxides Al(OR)3 (R = Et, iPr, tBu) with dialkylmalonates, viz. Al(malonate)3 (malonate = dimethyl, diethyl, di-iso-propyl and di-tert-butyl malonate), Al2(OiPr)4(malonate)2 (malonate = di-iso-propyl and di-tert-butyl malonate), Al2(OiPr)2(di-iso-propylmalonate)4 and Al3(OH)(OEt)3(diethylmalonate)5. All compounds were characterized by NMR spectroscopy, and single crystal structure analyses are reported for each type of compound. An Al2(OiPr)2(dialkylmalonate)4 derivative was only obtained by disproportionation of Al2(OiPr)4(di-iso-propylmalonate)2, but not by reaction of Al(OiPr)3 with dialkylmalonates in the corresponding molar ratio. Reactions of Al(OtBu)3 only resulted in Al(malonate)3 derivatives, but no transesterification was observed, contrary to the reaction of Al(OiPr)3 with dimethyl or diethyl malonate.

No MeSH data available.


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Molecular structure of 4 (C-bonded hydrogen atoms omitted for clarity)
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Fig9: Molecular structure of 4 (C-bonded hydrogen atoms omitted for clarity)

Mentions: Since the preparation of Al(detm)3 (1b) from Al(OiPr)3 and detm-H failed due to transesterification, an alternative preparative route was explored to avoid transesterification. Since Al(OEt)3 is oligomeric, it is only sparingly soluble in most organic solvents, including toluene. However, at least partial thermal de-oligomerization and subsequent partial solubility was expected, as for Al(OiPr)3, and therefore Al(OEt)3, dispersed in toluene, was reacted with three equiv. of detm-H at 90 °C. The solution immediately cleared upon heating. Monitoring of the reaction by 1H NMR spectroscopy clearly revealed coordination of the malonate, but significant differences to the spectrum of 1b were observed and greater proportions of unreacted detm-H were detected. Removal of all volatiles and storage of the obtained oil for a few days at room temperature yielded crystals, which turned out to be Al3(OH)(OEt)3(detm)5 (4) (Fig. 9).Fig. 9


Modification of aluminium alkoxides with dialkylmalonates.

Lichtenberger R, Baumann SO, Bendova M, Puchberger M, Schubert U - Monatsh. Chem. (2010)

Molecular structure of 4 (C-bonded hydrogen atoms omitted for clarity)
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4494765&req=5

Fig9: Molecular structure of 4 (C-bonded hydrogen atoms omitted for clarity)
Mentions: Since the preparation of Al(detm)3 (1b) from Al(OiPr)3 and detm-H failed due to transesterification, an alternative preparative route was explored to avoid transesterification. Since Al(OEt)3 is oligomeric, it is only sparingly soluble in most organic solvents, including toluene. However, at least partial thermal de-oligomerization and subsequent partial solubility was expected, as for Al(OiPr)3, and therefore Al(OEt)3, dispersed in toluene, was reacted with three equiv. of detm-H at 90 °C. The solution immediately cleared upon heating. Monitoring of the reaction by 1H NMR spectroscopy clearly revealed coordination of the malonate, but significant differences to the spectrum of 1b were observed and greater proportions of unreacted detm-H were detected. Removal of all volatiles and storage of the obtained oil for a few days at room temperature yielded crystals, which turned out to be Al3(OH)(OEt)3(detm)5 (4) (Fig. 9).Fig. 9

Bottom Line: Al(malonate)3 (malonate = dimethyl, diethyl, di-iso-propyl and di-tert-butyl malonate), Al2(OiPr)4(malonate)2 (malonate = di-iso-propyl and di-tert-butyl malonate), Al2(OiPr)2(di-iso-propylmalonate)4 and Al3(OH)(OEt)3(diethylmalonate)5.An Al2(OiPr)2(dialkylmalonate)4 derivative was only obtained by disproportionation of Al2(OiPr)4(di-iso-propylmalonate)2, but not by reaction of Al(OiPr)3 with dialkylmalonates in the corresponding molar ratio.Reactions of Al(OtBu)3 only resulted in Al(malonate)3 derivatives, but no transesterification was observed, contrary to the reaction of Al(OiPr)3 with dimethyl or diethyl malonate.

View Article: PubMed Central - PubMed

Affiliation: Institute of Materials Chemistry, Vienna University of Technology, Vienna, Austria.

ABSTRACT

Abstract: Depending on the reaction conditions, different aluminium dialkylmalonate derivatives were obtained by reaction of aluminium alkoxides Al(OR)3 (R = Et, iPr, tBu) with dialkylmalonates, viz. Al(malonate)3 (malonate = dimethyl, diethyl, di-iso-propyl and di-tert-butyl malonate), Al2(OiPr)4(malonate)2 (malonate = di-iso-propyl and di-tert-butyl malonate), Al2(OiPr)2(di-iso-propylmalonate)4 and Al3(OH)(OEt)3(diethylmalonate)5. All compounds were characterized by NMR spectroscopy, and single crystal structure analyses are reported for each type of compound. An Al2(OiPr)2(dialkylmalonate)4 derivative was only obtained by disproportionation of Al2(OiPr)4(di-iso-propylmalonate)2, but not by reaction of Al(OiPr)3 with dialkylmalonates in the corresponding molar ratio. Reactions of Al(OtBu)3 only resulted in Al(malonate)3 derivatives, but no transesterification was observed, contrary to the reaction of Al(OiPr)3 with dimethyl or diethyl malonate.

No MeSH data available.


Related in: MedlinePlus