52992-91-3Relevant academic research and scientific papers
Synthesis of new C3 symmetric amino acid- and aminoalcohol-containing chiral stationary phases and application to HPLC enantioseparations
Yu, Jeongjae,Armstrong, Daniel W.,Ryoo, Jae Jeong
, p. 74 - 84 (2017/12/26)
We recently reported a new C3-symmetric (R)-phenylglycinol N-1,3,5-benzenetricarboxylic acid-derived chiral high-performance liquid chromatography (HPLC) stationary phase (CSP 1) that demonstrated better results as compared to a previously described N-3,5-dintrobenzoyl (DNB) (R)-phenylglycinol-derived CSP. Over a decade ago, (S)-leucinol, (R)-phenylglycine, and (S)-leucine derivatives were used as the starting materials of 3,5-DNB-based Pirkle-type CSPs for chiral separation. In this study, three new C3-symmetric CSPs (CSP 2, 3, and 4) were prepared by combining the ideas and results mentioned above. Here we describe the synthetic procedures and applications of the new C3-symmetric CSPs (CSP 2–CSP 4).
A concise synthesis of (S)-(+)-ginnol based on catalytic enantioselective addition of commercially unavailable Di(n -alkyl)zinc to aldehydes and ketones
Hatano, Manabu,Mizuno, Tomokazu,Ishihara, Kazuaki
scheme or table, p. 2024 - 2028 (2010/10/04)
Catalytic, enantioselective n-alkyl addition of commercially unavailable di(n-alkyl)zinc reagents, which were prepared by a refined version of Charettes procedure with Grignard reagents, to aldehydes and ketones was developed. To minimize the side reactions in the catalysis by chiral phosphoramide ligand (1) or 3,3-diphosphoryl-BINOL ligand (2), a preparation of di(n-alkyl)zinc reagents with a 1:2.5:1.6 molar ratio of ZnClNaOMe/RMgCl under solvent-free conditions was essential. Optically pure (S)-(+)-ginnol (17) was readily synthesized in one step for the first time by the catalytic enantioselective n-nonylation of icosanal. Georg Thieme Verlag.
Kinetic resolution of hydroperoxides with enantiopure phosphines: Preparation of enantioenriched tertiary hydroperoxides
Driver, Tom G.,Harris, Jason R.,Woerpel
, p. 3836 - 3837 (2008/02/13)
An efficient reductive kinetic resolution strategy capable of accessing optically active tertiary hydroperoxides is reported. Readily accessible tertiary hydroperoxides are resolved with commercially available (R)- or (S)-xylyl-PHANEPHOS with selectivity factors as large as 37. The resulting bis(phosphine oxide) can be recycled in high yields. The isolated mono(phosphine oxide) intermediate resolved hydroperoxides with the same selectivity as the parent bisphosphine. Copyright
(5aS,10aS)-Octahydro-1H,5H-dipyrrolopyrazine "DPP" as Auxiliary Reagent for Enantioselctive Alkylations of Prochiral Carbonyl Compounds
Zadel, Guido,Breitmaier, Eberhard
, p. 1323 - 1326 (2007/10/02)
In the presence of one equivalent of the title compound "DPP" (1) prochiral carbonyl compounds 2 react with Grignard reagents 3 in THF to form enantioselectively alcohols 4 with up to 98percent ee, whereas the addition of one equivalent of triethylamine yields the opposite enantiomers with up to 97percent ee.The optimal molar ratio of 1 and magnesium reagent 3 was determined by cryoscopic measurements.Asymmetric induction is supposed to arise from transition states involving monomeric octahedral complexes of Grignard reagent, chiral solvent, and carbonyl compound.DPP (1) also catalyses Grignard alkylations, because a tenth of its stochiometric amount gives an enantiomeric eccess four times more than as expected.Prepared from (S)-proline, only the boat conformation of 1 induces the observed selectivity as detected by 13C-NMR spectroscopy. - Key Words: Dipyrrolopyrazine, (5aS,10aS)-octahydro-1H,5H- / 1,2-Addition, enantioselective / Grignard reagents / Chiral solvent /Cryoscopic measurements
HIGHLY ENANTIOSELECTIVE ADDITION OF (S)-LITHIOMETHYL 1-NAPHTHYL SULFOXIDE TO KETONES
Sakuraba, Hidetake,Ushiki, Shigeru
, p. 5349 - 5352 (2007/10/02)
The anion of (S)-(-)-methyl 1-naphthyl sulfoxide reacts enantioselectively with alkyl phenyl ketones to give (SsSc)-β-hydroxysulfoxides with diastereomeric excess (de) up to 100percent.Optical pure (S)-tertiary alcohols are prepared by desulfurization of the corresponding diastereomers.
Sulfoximine-Mediated Syntheses of Optically Active Alcohols
Johnson, Carl R.,Stark, Charles J.
, p. 1193 - 1196 (2007/10/02)
Optically active β-hydroxy sulfoximines were prepared, as diastereomeric pairs, by the addition the lithium derivative of optically active N,S-dimethyl-S-phenylsulfoximine to prochiral ketones and aldehydes.The ketone adducts after separation by medium-pr
Stereochemistry of amino-carbonyl compounds-VII. Absolute and ralative configuration of some diastereomeric 1,3-amino-alcohols.
Tramontini,Angiolini,Fouquey,Jacques
, p. 4183 - 4187 (2007/10/04)
The absolute configuration of (+)-4-dimethylamino-2,4-diphenyl-butan-2-ol and (+)-4-piperidino-2-phenyl-pentan-2-ol, the predominant diastereomers obtained by reaction of (+)-3-dimethylamino-1,3-diphenyl-propan-1-one with MeLi and (+)-3-piperidino-1-phenyl-butan-1-one with MeMgI, respectively, was determined by chemical correlation. The relative configurations of the diastereomers afforded by such reactions were thus assigned.
