92288-15-8Relevant articles and documents
Molecular recognition principles and stationary-phase characteristics of topoisomer-selective chemoaffinity materials for chromatographic separation of circular plasmid DNA topoisomers
Mahut, Marek,Lindner, Wolfgang,Laemmerhofer, Michael
, p. 859 - 862 (2012)
We recently discovered the molecular recognition capability of a quinine carbamate ligand attached to silica as a powerful chemoaffinity material for the chromatographic separation of circular plasmid topoisomers of different linking numbers. In this paper we develop structure-selectivity relationship studies to figure out the essential structural features for topoisomer recognition. By varying different moieties of the original cinchonan-derived selector, it was shown that intercalation by the quinoline moiety of the ligand as assumed initially as the working hypothesis is not an essential feature for topoisomer recognition during chromatography. We found that the key elements for topoisomer selectivity are the presence of a rigid weak anion-exchange site and a H-donor site separated from each other in a defined distance by a 4-atom spacer. Additionally, incorporation of the weak anion-exchange site into a cyclic ring structure provides greater rigidity of the ligand molecule and turned out to be advantageous, if not mandatory, for (close to) baseline separation.
Practical and highly selective sulfur ylide mediated asymmetric epoxidations and aziridinations using an inexpensive, readily available chiral sulfide. Applications to the synthesis of quinine and quinidine
Illa, Ona,Arshad, Muhammad,Ros, Abel,McGarrigle, Eoghan M.,Aggarwal, Varinder K.
supporting information; experimental part, p. 1828 - 1830 (2010/04/25)
(Chemical Presented) Heating one of the most abundant naturally occurring inorganic chemicals (elemental sulfur) with one of the most readily available homochiral molecules (limonene) gives a one-step synthesis of a chiral sulfide which exhibits outstanding selectivities in sulfur ylide mediated asymmetric epoxidations and aziridinations. In particular reactions of benzyl and allylic sulfonium salts with both aromatic and aliphatic aldehydes gave epoxides with perfect enantioselectivities and the highest diastereoselectivities reported to date. In addition reactions with imines gave aziridines again with the highest enantioselectivities and diastereoselectivities reported to date. The reactions are scaleable, and the sulfide can be reisolated in high yield. The epoxidation has been used as the key step in a convergent and stereoselective synthesis of each of the diastereoisomers of the cinchona alkaloids, quinine and quinidine. Copyright
4-(1-AMINO-ETHYL)-CYCLOHEXYLAMINE DERIVATIVES
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Page/Page column 95, (2008/12/06)
The invention relates to compounds of formula (I) wherein R0 represents H or OH; R1 represents alkoxy; U and W represent N, V represents CH and R2 represents H or F, or U and V represent CH, W represents N and R2/sup