791121-08-9Relevant academic research and scientific papers
An aromatic ion platform for enantioselective Br?nsted acid catalysis
Gheewala, Chirag D.,Collins, Bridget E.,Lambert, Tristan H.
, p. 961 - 965 (2016)
Chiral acid catalysts are useful for the synthesis of enantioenriched small molecules, but the standard catalysts require laborious and expensive preparations. Here, we describe a chiral Br?nsted acid prepared in one step from naturally occurring (-)-menthol and readily available 1,2,3,4,5-pentacarbomethoxycyclopentadiene. Aromatic stabilization serves as a key contributing factor to the potent acidity of the resulting compound, which is shown to catalyze both Mukaiyama-Mannich and oxocarbenium aldol reactions with high efficiency and enantioselectivity. Catalyst loadings as low as 0.01 mole percent and preparative scalability (25 grams) are demonstrated. Alternative amide catalysts are also shown to be promising platforms. In addition to proton catalysis, a chiral anion pathway is demonstrated to be viable with this catalyst system.
ASYMMETRIC-SYNTHESIS CATALYST BASED ON CHIRAL BROENSTED ACID AND METHOD OF ASYMMETRIC SYNTHESIS WITH THE CATALYST
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Page/Page column 38, (2010/11/08)
A compound usable as an asymmetric synthesis catalyst which can be easily synthesized without using any metal such as a lanthanoid group element; a method of asymmetric synthesis with the compound; and a chiral compound obtained by the asymmetric synthesis method. A Broensted acid is used as a catalyst in asymmetric synthesis, the chiral Broensted acid being represented by formula (1) below or formula (3) below. The asymmetric synthesis method employs the catalyst. Asymmetric synthesis with the catalyst gives a chiral compound.
