A parallel approach to direct resolution of albuterol

Zhong, QingLin; Peng, Xiaohua; Wu, Tongfei; Fu, FangMin; Cui, Xin; Zhu, Jin; Deng, Jingen

doi:10.1007/s11434-010-3156-x

Cited by 3 publications

(3 citation statements)

References 14 publications

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“…4e On the contrary, 4k containing an electron-withdrawing nitro group gave a clean transformation in excellent enantioselectivity (95% ee). The reduction products of 4l and 4m were the key medicinal intermediates of anti-asthma drugs, terbutaline 16 and salbutamol 17 . Although prolonged time was required for full conversion of 4l and 4m, the corresponding reduction products were generated both with 93% ee in satisfactory yields.…”

Section: Asymmetric Aqueous Phase Transfer Hydrogenationmentioning

confidence: 99%

Surfactant-accelerated asymmetric transfer hydrogenation with recyclable water-soluble catalyst in aqueous media

et al. 2013

RSC Adv.

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Water-soluble ligands (R,R)-2 were successfully prepared, in which the bis-meta-sulphonated ligand was definitely detected as the major product. The corresponding transition-metal complexes containing the ligands displayed excellent catalytic performance in asymmetric transfer hydrogenation (ATH) of aromatic ketones. Especially, the aromatic ketones with a bromine group in the a position could be smoothly reduced to the expected alcohol, keeping the bromine group intact with excellent enantioselectivities (up to 96% ee). The catalyst could be reused at least 21 times without erosion of the enantioselectivity in high conversion. Moreover, it was found that cationic surfactant and proper pH values were necessary for the maintenance of high reactivity.

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Section: Asymmetric Aqueous Phase Transfer Hydrogenationmentioning

confidence: 99%

Surfactant-accelerated asymmetric transfer hydrogenation with recyclable water-soluble catalyst in aqueous media

et al. 2013

RSC Adv.

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“…General: (2R,3R)-2,3-Bis(3,5-dimethylbenzoyl)tartaric acid (2 a), [29] (2R,3R)-2,3-bis(4-t-butylbenzoyl)tartaric acid (2 b), [30] (2R,3R)-2,3-bis (3,5-di-t-butylbenzoyl)tartaric acid (2 c) [31] and (2R,3R)-2,3-bis (cyclohexanecarbonyl)tartaric acid (2 f) [32] were also prepared according to procedures reported in the literature. (2R,3R) 5dimethylbenzoyl) (Eurisotop) were obtained from commercial sources and were used without further purification.…”

Section: Methodsmentioning

confidence: 99%

“…General : (2 R ,3 R )‐2,3‐Bis(3,5‐dimethylbenzoyl)tartaric acid ( 2 a ), [29] (2 R ,3 R )‐2,3‐bis(4‐ t ‐butylbenzoyl)tartaric acid ( 2 b ), [30] (2 R ,3 R )‐2,3‐bis(3,5‐di‐ t ‐butylbenzoyl)tartaric acid ( 2 c ) [31] and (2 R ,3 R )‐2,3‐bis(cyclohexanecarbonyl)tartaric acid ( 2 f ) [32] were also prepared according to procedures reported in the literature. (2 R ,3 R )‐2,3‐Bis(3,5‐dimethylbenzoyl)tartaric acid ( 2 d , Tokyo Chemical Industry), (2 R ,3 R )‐2,3‐dibenzoyltartaric acid ( 2 e , Tokyo Chemical Industry), (2 R ,3 R ) ‐ tartaric acid ( 3 Fujifilm Wako, L ‐form), (1 S ,2 S )‐cyclohexane‐1,2‐dicarboxylic acid ( 4 , Tokyo Chemical Industry), (1 R ,3 S )‐(+)‐camphoric acid ( 5 , Sigma Aldrich), ( S )‐2‐pyrrolidone‐5‐carboxylic acid ( 6 , Fujifilm Wako), N ‐(9‐Fmoc)‐ L ‐glutamic acid 5‐ t ‐butyl ester ( 7 , Sigma Aldrich), ( R )‐1,1′‐binaphthyl‐2,2′‐diyl hydrogenphosphate (8 , Tokyo Chemical Industry), ( R )‐ O ‐acetylmandelic acid ( 9 , Sigma Aldrich), DMSO‐ d 6 (Euriso‐top), DMF‐ d 7 (Acros Organics), toluene‐ d 8 (Euriso‐top), nitrobenzene‐ d 5 (Euriso‐top) and dichloromethane‐ d 2 (Euriso‐top) were obtained from commercial sources and were used without further purification.…”

Section: Methodsmentioning

confidence: 99%

Catalytic Enantioselective Rotation of Watermill‐Shaped Dinuclear Pd Complexes

et al. 2021

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The catalytic enantioselective rotation of double-paddled, watermill-shaped palladium complexes is described in this report. The achiral syn-and chiral anti-forms of binuclear transbis(salicylaldiminato)palladium(II) complexes doubly linked with polymethylene bridges (1) were synthesized and subsequently characterized by spectroscopic and single crystal XRD analyses. The heptamethylene-linked complex 1 b undergoes highly controllable rotation between the achiral syn and chiral antiforms at ambient temperature, while the hexamethylene-linked analogue 1 a does not exhibit this rotational motion under the same conditions, due to its shorter bridges, and 1 c (with octamethylene linkers) undergoes uncontrollable rapid rotation even at lower temperatures. The kinetics of the dynamic rotation of syn-1 b to the anti-isomer in solution were examined on the basis of 1 H NMR analyses. The data showed that the rotational rate can be greatly modified by varying the solvent or adding a carboxylic acid. The enantioselective rotation of syn-1 b can be induced using a catalytic amount of (2R,3R)-2,3bis(3,5-dimethylbenzoyl)tartaric acid (2 a) to afford (R)-anti-1 b, with an initial enantiomeric excess of 63 % ee and an equilibrium value of 27 % ee. Curve fitting of data for the parallel reversible transformations of syn-1 b to (R) and (S)-anti-1 b gave the forward and reverse first-order rate constants k 1 , k À 1 (for syn to (R)-anti), k 2 and k À 2 (syn-to (S)-anti), and verified that the enantioselective nature of the present catalytic enantioselective rotation is controlled kinetically during the initial stage (k 1 > k 2 ) and thermodynamically in the equilibrium state (k 1 /k À 1 > k 2 /k À 2 ). The specific changes induced in the transition states in response to the use of various solvents and adducts are discussed herein on the basis of the activation parameters for the rotation of syn-1 b, as determined from plots of the kinetic data as functions of time.

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Resolution of Rac‐Bambuterol via Diastereoisomeric Salt Formation with o‐Chloromandelic Acid and Differences in the Enantiomers' Pharmacodynamical Effects in Guinea Pigs and Beagles

Liu

Wang

et al. 2016

Chirality

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In this study an enantioseparation method for rac-bambuterol (5-(2-(tert-butylamino)-1-hydroxyethyl)-1,3-phenylene bis(dimethylcarbamate)) via diastereoisomeric salt formation with o-chloromandelic acid was developed. The enantiomeric excess (ee) values and chemical purities of the desired products were confirmed by high-performance liquid chromatography (HPLC) using chiral stationary phase and reverse-phase HPLC analyses, respectively. The ee values and the chemical purities both exceeded 99%. Animal experiments showed that (R)-bambuterol was a potent inhibitor for histamine-induced asthma reactions. (S)-bambuterol was ineffective in relaxing the airways. Both enantiomers increased heart rates in beagles. Therefore, replacing rac-bambuterol with (R)-bambuterol could be beneficial for asthma patients.

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A parallel approach to direct resolution of albuterol

Cited by 3 publications

References 14 publications

Surfactant-accelerated asymmetric transfer hydrogenation with recyclable water-soluble catalyst in aqueous media

Surfactant-accelerated asymmetric transfer hydrogenation with recyclable water-soluble catalyst in aqueous media

Catalytic Enantioselective Rotation of Watermill‐Shaped Dinuclear Pd Complexes

Resolution of Rac‐Bambuterol via Diastereoisomeric Salt Formation with o‐Chloromandelic Acid and Differences in the Enantiomers' Pharmacodynamical Effects in Guinea Pigs and Beagles

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