52992-90-2Relevant 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).
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
Synthesis of enantioenriched tertiary benzylic alcohols via stereospecific lithiation of secondary benzyl carbamates - Design of dialkylcarbamates, cleavable under basic, mild conditions
Derwing, Christoph,Hoppe, Dieter
, p. 149 - 154 (2007/10/03)
Enantiomerically enriched, secondary benzyl N-[2-(tert-butyldiphenylsilyloxy)ethyl]-N-isopropylcarbamates were prepared, lithiated, and stereospecifically substituted by several electrophiles. Deprotection under basic conditions furnished optically active tertiary benzylic alcohols and glycols or 2-hydroxy-2-arylalkanoic acid esters. In summary, the sequence achieves the stereospecific chain elongation of d1-synthons, derived from secondary benzyl alcohols.
(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
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.
