119322-88-2Relevant academic research and scientific papers
A new chiral sulfonamide ligand based on tartaric acid: synthesis and application in the enantioselective addition of diethylzinc to aldehydes and ketones
Hui, Ailing,Zhang, Jintang,Fan, Jinmin,Wang, Zhiyong
, p. 2101 - 2107 (2006)
A new sulfonamide ligand based on l-tartaric acid was synthesized and was employed as a chiral ligand in the enantioselective addition of diethylzinc to aldehydes, giving rise to the best enantiomeric excess up to 83% with 5 mol % of catalyst loading. Moreover, the addition of diethylzinc to ketones can also be achieved with good to excellent enantioselectivities by employing 7 mol % of the catalyst under mild conditions.
Enantioselective α-Hydroxylation by Modified Salen-Zirconium(IV)-Catalyzed Oxidation of β-Keto Esters
Yang, Fan,Zhao, Jingnan,Tang, Xiaofei,Zhou, Guangli,Song, Wangze,Meng, Qingwei
, p. 448 - 451 (2017)
The highly enantioselective α-hydroxylation of β-keto esters using cumene hydroperoxide (CHP) as the oxidant was realized by a chiral (1S,2S)-cyclohexanediamine backbone salen-zirconium(IV) complex as the catalyst. A variety of corresponding chiral α-hydroxy β-keto esters were obtained in excellent yields (up to 99%) and enantioselectivities (up to 98% ee). The zirconium-catalyzed enantioselective α-hydroxylation of β-keto esters was scalable, and the zirconium catalyst was recyclable. The reaction can be performed in gram scale, and corresponding chiral products were acquired in 95% yield and 99% ee.
Two new phenolic amides from the seeds of Pharbitis nil
Kim, Ki Hyun,Choi, Sang Un,Son, Mi Won,Lee, Kang Ro
, p. 1532 - 1535 (2010)
Two new phenolic amides, pharnilatins A (1) and B (2), were isolated from the seeds of Pharbitis nil. These new compounds possess a p-coumaroyl unit with a structurally unique side chain, (2S,3S)-2,3-dihydroxyputrescine. The chemical structures and absolute stereochemistries of the new compounds were determined on the basis of spectroscopic analyses including 1D- and 2D-NMR experiments and chemical reactions. Compounds 1 and 2 exhibited cytotoxicity against A549, SK-OV-3, SK-MEL-2, and HCT-15 human tumor cells. However, none of the compounds inhibited nitric oxide (NO) production in lipopolysaccharide (LPS)-activated microglia cells.
Asymmetric hydrogen-transfer hydrogenation on rhodium(I) complexes with new optically active salen ligands derived from (4S,5S)-4,5-Bis(aminomethyl)-2,2- dimethyl-1,3-dioxolane
Nindakova,Shainyan,Badyrova,Lebed'
, p. 59 - 63 (2012)
New optically active C2-symmetric salen-type ligands were synthesized on the basis of (4S,5S)-4,5-bis(aminomethyl)-2,2-dimethyl-1,3-dioxolane. These ligands were used to obtain cationic (trifluoromethanesulfonate) and neutral (chloride) rhodium(I) complexes with [(4S,5S)-2,2-dimethyl-5-{[(E)-pyridin-2- ylmethylidene]aminomethyl}-1,3-dioxolan-4-yl]-N-[(E)-pyridin-2-ylmethylidene] methanamine and [2,2-dimethyl-5-{[(E)-quinolin-2-ylmethylidene]aminomethyl}-1,3- dioxolan-4-yl]-N-[(E)-quinolin-2-ylmethylidene] methanamine. The latter complex ensured preparation of (S)-2-phenylethanol with an optical yield of 34.8% by transfer hydrogenation of acetophenone. Pleiades Publishing, Ltd., 2012.
The Detosylation of Chiral 1,2-Bis(tosylamides)
Gaston, Jayden J.,Tague, Andrew J.,Smyth, Jamie E.,Butler, Nicholas M.,Willis, Anthony C.,van Eikema Hommes, Nico,Yu, Haibo,Clark, Timothy,Keller, Paul A.
, p. 9163 - 9180 (2021/07/19)
The deprotection of chiral 1,2-bis(tosylamides) to their corresponding 1,2-diamines is mostly unsuccessful under standard conditions. In a new methodology, the use of Mg/MeOH with sufficient steric additions allows the facile synthesis of 1,2-diamines in 78-98% yields. These results are rationalized using density functional theory and the examination of inner and outer-sphere reduction mechanisms.
Ring-opening and -expansion of 2,2′-biaziridine: Access to diverse enantiopure linear and bicyclic vicinal diamines
Bailey, Stephen J.,Wales, Steven M.,Willis, Anthony C.,Keller, Paul A.
, p. 4344 - 4347 (2014/10/16)
The chiral pool-derived 1,1′-ditosyl-2,2′-biaziridine has been established as a valuable building block for the divergent synthesis of enantiopure vicinal diamines. Efficient procedures for the regioselective ring opening of the biaziridine with oxygen, sulfur, nitrogen, and carbon nucleophiles are described. The strategic use of nucleophiles bearing pendant functionality allows further elaboration of the acyclic products to a variety of 2,2′-bicyclic-embedded diamines. Desymmetrization of the biaziridine has also been accomplished via the selective monoaddition of organocuprates.
Cyclic sulfamide HIV-1 protease inhibitors, with sidechains spanning from P2/P2′ to P1/P1′
Ax, Anna,Schaal, Wesley,Vrang, Lotta,Samuelsson, Bertil,Hallberg, Anders,Karlén, Anders
, p. 755 - 764 (2007/10/03)
Previous studies of HIV protease inhibitors have shown that it is possible to elongate the P1/P1′ sidechains to reach the S3/S3′ binding sites. By analogy, we expected that it would be possible to design inhibitors reaching between the S1/S1′ and S2/S2′ b
Catalytic asymmetric phase-transfer reactions using tartrate-derived asymmetric two-center organocatalysts
Ohshima, Takashi,Shibuguchi, Tomoyuki,Fukuta, Yuhei,Shibasaki, Masakatsu
, p. 7743 - 7754 (2007/10/03)
A new highly versatile asymmetric two-center catalyst, tartrate-derived diammonium salt (TaDiAS), was designed and a catalyst library containing more than 70 new two-center catalysts was constructed. A variety of (S,S)- and (R,R)-TaDiAS were easily synthesized from diethyl L- and D-tartrate, respectively, using common and inexpensive reagents under operationally simple reaction conditions. TaDiAS was used in phase-transfer alkylations and Michael additions to afford various optically active α-amino acid equivalents in up to 93% yield. Moreover, dramatic counter anion effects were observed in phase-transfer catalysis (PTC) for the first time, making it possible to further improve reactivity and selectivity. These findings validate the usefulness of three-dimensional fine-tuning of the catalyst (acetal, Ar, and counter anion) for optimization. Recovery and reuse of the catalyst was also possible using simple procedures. The present asymmetric PTC was successfully applied to enantioselective syntheses of serine protease inhibitor aeruginosin 298-A and its analogues.
Diamines having a C2 symmetry. Synthesis and application as ligands in the hydrogenation of prochiral substrates over rhodium complexes
Shainyan,Ustinov,Bel'skii,Nindakova
, p. 104 - 110 (2007/10/03)
Chiral diamines having a C2 symmetry, (4S,5S)-2,2-dimethyl-4,5-bis(aminomethyl)-1,3-dioxolane and (5S,5′ S)-2,2,2′,2′-tetramethyl-3,3′-diphenyl-5,5′ -bioxazolidine, were synthesized on the basis of (+)-(2R,3R)-tartaric acid. Their structure was proved by X-ray analysis. The products were used as ligands in rhodium catalyst for enantioselective hydrogenation of α -acetamidocinnamic and itaconic acids.
