41024-90-2Relevant academic research and scientific papers
Influence of stereoregularity and linkage groups on chiral recognition of poly(phenylacetylene) derivatives bearing L -leucine ethyl ester pendants as chiral stationary phases for HPLC
Zhang, Chunhong,Liu, Fangbin,Li, Yufa,Shen, Xiande,Xu, Xiaodong,Sakai, Ryosuke,Satoh, Toshifumi,Kakuchi, Toyoji,Okamoto, Yoshio
, p. 2271 - 2278 (2013)
Stereoregular poly(phenylacetylene) derivatives bearing L-leucine ethyl ester pendants, poly-1 and poly-2a, were, respectively, synthesized by the polymerization of N-(4-ethynylphenylcarbamoyl)-L-leucine ethyl ester (1) and N-(4-ethynylphenyl-carbonyl)-L-leucine ethyl ester (2) using Rh(nbd)BPh 4 as a catalyst, while stereoirregular poly-2b was synthesized by solid-state thermal polymerization of 2. Their chiral recognition abilities for nine racemates were evaluated as chiral stationary phases (CSPs) for high-performance liquid chromatography (HPLC) after coating them on silica gel. Both poly-1 and poly-2a with a helical conformation showed their characteristic recognition depending on coating solvents and the linkage groups between poly(phenylacetylene) and L-leucine ethyl ester pendants. Poly-2a with a shorter amide linkage showed higher chiral recognition than poly-1 with a longer urea linkage. Coating solvents played an important role in the chiral recognition of both poly-1 and poly-2a due to the different conformation of the polymer main chains induced by the solvents. A few racemates were effectively resolved on the poly-2a coated with a MeOH/CHCl3 (3/7, v/v) mixture. The separation factors for these racemates were comparable to those obtained on the very popular CSPs derived from polysaccharide phenylcarbamates. Stereoirregular poly-2b exhibited much lower chiral recognition than the corresponding stereoregular, helical poly-2a, suggesting that the regular structure of poly(phenylacetylene) main chains is essential to attain high chiral recognition.
Immobilization and chromatographic evaluation of novel regioselectively substituted amylose-based chiral packing materials for HPLC
Shen, Jun,Li, Pengfei,Liu, Shuangyan,Shen, Xiande,Okamoto, Yoshio
scheme or table, p. 878 - 886 (2012/06/30)
The regioselectively substituted amylose derivatives bearing a 4-tert-butylbenzoate or 4-chlorobenzoate group at 2-position, and 3,5-dichlorophenylcarbamate and a small amount of 3-(triethoxysilyl) propylcarbamate groups at 3- and 6-positions were synthesized by a two-step process based on the esterification of 2-position of a glucose unit. The obtained derivatives were effectively immobilized onto macroporous silica gel by intermolecular polycondensation of triethoxysilyl groups. Their chiral recognition abilities were evaluated as chiral packing materials (CPMs) for high-performance liquid chromatography. These CPMs showed high chiral recognition as well as the conventional coated-type CPM, and can be used with the eluents-containing chloroform and tetrahydrofuran. With the extended use of these eluents, improvement of chiral recognition and reversed elution orders were realized. For some racemates, the immobilized CPM exhibited ability comparable or better to the commercial immobilized amylose- or cellulose-based columns,
Synthesis of New Alkyl Derivatives of 2,2'-Dihydroxy-1,1'-binaphthyl
Koy, Cornelia,Michalik, Manfred,Oehme, Guenther,Fischer, Christine,Tillack, Annegret,Baudisch, Hannelore,Kempe, Rhett
, p. 203 - 228 (2007/10/03)
2'-Hydroxy-1,1'-binaphthyl-2-yl phosphate 4 reacts with various alkylating agents under controlled conditions to give differently alkylated phosphoric esters 5-9. The monoalkylation of binaphthol 1 with long-chain alkyl halides followed by reaction with phosphoryl chloride, propane-1,3-sultone or chlorosulfuric acid, respectively, yielded the amphiphilic binaphthyl derivatives 14-17. The compounds prepared were fully characterized by spectroscopic methods.
Lipase-catalyzed Stereoselective Acylation of -2,2'-diol and Deacylation of Its Esters in an Organic Solvent
Inagaki, Minoru,Hiratake, Jun,Nishioka, Takaaki,Oda, Jun'ichi
, p. 1879 - 1884 (2007/10/02)
A kinetic resolution of -2,2'-diol (binaphthol) and its esters was first accomplished by lipase-catalyzed transesterification in an organic solvent.Acylation of binaphthol with enol esters in diisopropyl ether-acetone (9:1, v/v) gave solely (R)-2-acyloxy-2'-hydroxy-1,1'-binaphthyl (binaphthyl monoesters) having 90-95percent optical purities.The unreacted binaphthol, which was also recovered in high chemical yields, was the S enantiomer with 69-89percent e.e.On the other hand, the lipase-catalyzed deacylation or alcoholysis of racemic binaphthyl monoesters gave (S)-monoesters and (R)-binaphthol in high chemical and optical yields (>90percent e.e.).In deacylation, the reaction period was much shortened by introducing the more electronegative chlorine atom into the acetyl group of the substrate.
Optical Resolution of Sulfoximines by Complex Formation with Optically Active 2,2'-Dihydroxy-1,1'-binaphthyl or 1,6-Di(o-chlorophenyl)-1,6-diphenylhexa-2,4-diyne-1,6-diol
Mori, Koji,Toda, Fumio
, p. 1997 - 2000 (2007/10/02)
Some alkyl aryl and dialkyl sulfoximines were resolved efficiently by complex formation with optically active 2,2'-dihydroxy-1,1'-binaphthyl and 1,6-di(o-chlorophenyl)-1,6-diphenylhexa-2,4-diyne-1,6-diol, respectively.
