191403-65-3Relevant academic research and scientific papers
Intercepted dehomologation of aldoses by N-heterocyclic carbene catalysis-a novel transformation in carbohydrate chemistry
Draskovits, Markus,Kalaus, Hubert,Stanetty, Christian,Mihovilovic, Marko D.
, p. 12144 - 12147 (2019/10/21)
The development of an N-heterocyclic carbene (NHC) catalysed intercepted dehomologation of aldoses is reported. The unique selectivity of NHCs for aldehydes is exploited in the complex context of reducing sugars. Examples of strong substrate governance for either intercepted dehomologation or a subsequent redox-lactonisation were identified and mechanistically understood. More importantly, it was shown that catalyst design allowed the tuning of the selectivity of the reaction with structurally unbiased starting materials towards either of the two scenarios.
A novel derivatization procedure and chiral gas chromatographic method for enantiomeric purity screening of L-carnitine
Albreht, Alen,Zupani, Borut,Vovk, Irena
, p. 889 - 893 (2015/02/05)
L-Carnitine is used extensively in functional foods and food supplements; consequently, the control of its enantiomeric purity is of paramount importance. A new derivatization procedure and chiral gas chromatographic method with flame ionization detection, using a cyclodextrin based stationary phase, enables prompt, simple, and inexpensive screening of the enantiomeric ratio of L- and D-carnitine in samples with different matrices. Conversion of carnitine to β-acetoxy-γ- butyrolactone was optimized for maximum conversion (98% of the desired product lactone was formed and 2% of the side product γ-crotonolactone) and minimum racemization (no changes at the chiral center were detected) and time consumption. As it is shown in this study, a fast gas chromatographic method, with total run time of 7 min, together with the new derivatization procedure enables an effective enantiomeric purity screening of L-carnitine in real samples such as food supplements and L-carnitine raw ingredient.
N-HETEROCYCLIC CARBENE-AMIDO PALLADIUM(II) CATALYSTS AND METHOD OF USE THEREOF
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Page/Page column 7, (2010/03/02)
A new N-heterocyclic catalyst system which contains N-heterocyclic carbene and amido as ligands, which are strongly bound to a palladium metal. Another heteroatom functionality can be used as a third ligand L. The NHC-amidate ligand system is unique in structure, and shows excellent reactivities in a number of chemical reactions. The chemical reactions include carbon-carbon and carbon-heteroatom (oxygen and nitrogen) bond formations, and oxidation reactions of saturated carbon chemicals via C—H activation.
Beta-substituted-gamma-butyrolactones and a process for preparation thereof
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Page 6, (2008/06/13)
The present invention is related to a process for the preparation of (S)- or (R)-β-substituted-γ-butyrolactones or a racemic mixture thereof. β-substituted-γ-succinic anhydrides are converted by zinc borohydride in a compatible solvent selected from tetra
