A highly negatively charged γ-Keggin germanodecatungstate efficient for Knoevenagel condensation.

A highly negatively charged γ-Keggin germanodecatungstate efficient for Knoevenagel condensation.

Chemical communications (Cambridge, England) (2012-07-14)

Kosei Sugahara, Toshihiro Kimura, Keigo Kamata, Kazuya Yamaguchi, Noritaka Mizuno

ABSTRACT

A tetra-n-butylammonium (TBA) salt of a γ-Keggin -6-charged germanodecatungstate, [γ-H(2)GeW(10)O(36)](6-) (I), could act as an efficient homogeneous catalyst for Knoevenagel condensation of active methylene compounds with carbonyl compounds.

MATERIALS

Product Number

Brand

Product Description

79989

Sigma-Aldrich

Tetrabutylammonium cyanide, technical, ≥80%

86885

Sigma-Aldrich

Tetrabutylammonium perchlorate, ≥95.0% (T)

86880

Sigma-Aldrich

Tetrabutylammonium hydroxide solution, technical, ~40% in H₂O (~1.5 M)

86854

Supelco

Tetrabutylammonium hydroxide solution, ~40% in water, suitable for ion chromatography

86863

Sigma-Aldrich

Tetrabutylammonium hydroxide solution, 53.5-56.5% in H₂O

155837

Sigma-Aldrich

Tetrabutylammonium hydrogensulfate, 97%

230189

Sigma-Aldrich

Tetrabutylammonium hydroxide solution, 1.0 M in methanol

358665

Sigma-Aldrich

Tetrabutylammonium cyanide, 95%

268100

Sigma-Aldrich

Tetrabutylammonium phosphate monobasic solution, 1.0 M in H₂O

86893

Supelco

Tetrabutylammonium perchlorate, for electrochemical analysis, ≥99.0%

178780

Sigma-Aldrich

Tetrabutylammonium hydroxide solution, 40 wt. % in H₂O

651664

Sigma-Aldrich

Tetrabutylammonium azide

86890

Sigma-Aldrich

Tetrabutylammonium iodide, ≥99.0% (AT)

98479

Supelco

Tetrabutylammonium bisulfate solution, suitable for ion pair chromatography, LiChropur^™, concentrate, ampule

193119

Sigma-Aldrich

Tetrabutylammonium bromide, ReagentPlus^®, ≥99.0%

426288

Sigma-Aldrich

Tetrabutylammonium bromide, ACS reagent, ≥98.0%

361399

Sigma-Aldrich

Tetrabutylammonium fluoride solution, 75 wt. % in H₂O

359173

Sigma-Aldrich

Tetrabutylammonium nitrate, 97%

86868

Sigma-Aldrich

Tetrabutylammonium bisulfate, puriss., ≥99.0% (T)

86853

Supelco

Tetrabutylammonium bisulfate, suitable for ion pair chromatography, LiChropur^™, ≥99.0%

86857

Supelco

Tetrabutylammonium bromide, suitable for ion pair chromatography, LiChropur^™, ≥99.0%

86833

Sigma-Aldrich

Tetrabutylammonium phosphate monobasic, puriss., 99% (T)

86852

Supelco

Tetrabutylammonium chloride, suitable for ion pair chromatography, LiChropur^™, ≥99.0%

216143

Sigma-Aldrich

Tetrabutylammonium fluoride solution, 1.0 M in THF

86870

Sigma-Aldrich

Tetrabutylammonium chloride, ≥97.0% (NT)

140775

Sigma-Aldrich

Tetrabutylammonium iodide, reagent grade, 98%

462144

Sigma-Aldrich

Tetrabutylammonium bromide solution, 50 wt. % in H₂O

72453

Sigma-Aldrich

Tetrabutylammonium bisulfate solution, ~55% in H₂O

86903

Supelco

Tetrabutylammonium iodide, suitable for ion pair chromatography, LiChropur^™, ≥99.0%