- Palladium-Catalyzed Asymmetric Dihydroxylation of 1,3-Dienes with Catechols
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A palladium-catalyzed asymmetric dihydroxylation of 1,3-dienes with catechols is developed using chiral pyridinebis(oxazoline) ligands. Various chiral 2-substituted 1,4-benzodioxanes could be synthesized with moderate to high yields and enantioselectivities from readily available starting materials. The reaction is proposed to proceed through a cascade Wacker-type hydroxypalladation/asymmetric allylation process.
- Fan, Tao,Shen, Hong-Cheng,Han, Zhi-Yong,Gong, Liu-Zhu
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- Enantioselective Synthesis of Chiral Oxygen-Containing Heterocycles Using Copper-Catalyzed Aryl C-O Coupling Reactions via Asymmetric Desymmetrization
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An enantioselective desymmetric aryl C-O coupling reaction was demonstrated under the catalysis of CuI and a chiral cyclic diamine ligand. A series of chiral oxygen-containing heterocyclic units such as 2,3-dihydrobenzofurans, chromans, and 1,4-benzodioxanes with tertiary or quaternary stereocarbon centers were synthesized with this method. DFT calculations were also carried out for a better understanding of the model for enantiocontrol.
- Zhang, Yong,Wang, Qiuyan,Wang, Ting,He, Huan,Yang, Wenqiang,Zhang, Xinhao,Cai, Qian
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- Synthesis of enantiomerically pure 7-hydroxy-2-substituted-2,3-dihydro-1,4-benzodioxin derivatives
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A rapid and simple procedure for the preparation of the two pure enantiomers of 7-hydroxy-2-substituted-2,3-dihydro-1,4-benzodioxin derivatives is described.
- Khouili,Lazar,Guillaumet,Coudert
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- Method for synthesizing optically pure 2-hydroxymethyl-1,4-benzodioxin and derivatives of optically pure 2-hydroxymethyl-1,4-benzodioxin
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The invention discloses a method for synthesizing optically pure 2-hydroxymethyl-1,4-benzodioxin and derivatives of the optically pure 2-hydroxymethyl-1,4-benzodioxin. The method comprises the steps that cheap 2-bromophenol or derivatives of the 2-bromoph
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Paragraph 0030-0032; 0034
(2019/06/30)
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- Preparation method of 1,4-benzdioxan-2-formic acid
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The invention provides a preparation method of 1,4-benzdioxan-2-formic acid. The preparation method comprises the following steps: by taking benzylodiglycidyl ether and o-halogen phenol as raw materials, performing cyclization reaction, debenzylation reaction and oxidization reaction to obtain the 1,4-benzdioxan-2-formic acid. The preparation method provided by the invention is simple in reactionprocess; as the benzylodiglycidyl ether and the o-halogen phenol are used as the raw materials for reaction, no pollutants are produced, and no-irritative and no-allergic objects are produced; compared with other existing lines, the preparation method is environmentally friendly, high in total yield and favorable for mass production; the ee value of the finally prepared 1,4-benzdioxan-2-formic acid is more than or equal to 99 percent, and the chiral purity is high.
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- Method for synthesizing asymmetric C-O coupled compound and application of asymmetric C-O coupled compound
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The invention discloses a method for synthesizing an asymmetric C-O coupled compound and application of the asymmetric C-O coupled compound and belongs to the technical field of chemical synthesis. According to the method, a compound represented by a form
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- DOPAMINE D2 RECEPTOR LIGANDS
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The present invention relates to novel dopamine D2 receptor ligands. The invention further relates to functionally-biased dopamine D2 receptor ligands and the use of these compounds for treating or preventing central nervous system and systemic disorders associated with dysregulation of dopaminergic activity. The present invention relates to novel compounds that modulate dopamine D2 receptors. In particular, compounds of the present invention show functional selectivity at the dopamine D2 receptors and exhibit selectivity downstream of the D2 receptors, on the 0- arrestin pathway and/or on the cAMP pathway.
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Page/Page column 148; 149
(2016/07/05)
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- Method for synthesizing doxazosin
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The invention discloses a method for synthesizing doxazosin and belongs to the technical field of chemical synthesis. According to the method, the doxazosin is synthesized by adopting a synthesis route, represented by formulae shown in the description, different from the conventional technologies, and thus a novel synthesis route is provided for preparing the doxazosin; and the method has the advantages of moderate conditions, simple and convenient steps and high yield, and the doxazosin can be obtained simply and efficiently.
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Paragraph 0088; 0090; 0091; 0092; 0093; 0094; 0017; 0018
(2017/01/12)
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- Pd-catalyzed asymmetric intramolecular aryl c-o bond formation with SDP(O) ligand: Enantioselective synthesis of (2,3-Dihydrobenzo[ b ][1,4]dioxin-2-yl)methanols
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Employing a chiral spirodiphosphine monoxide ligand with 1,1′-spirobiindane backbone (SDP(O)), a desymmetrization strategy of Pd-catalyzed intramolecular asymmetric aryl C-O coupling of 2-(2-halophenoxy)propane-1,3-diols, was developed. The SDP(O) ligand shows much better results than its SDP counterpart. The protocol provides an efficient and highly enantioselective method for the synthesis of 2-hydroxymethyl-1,4-benzodioxanes. Density functional theory studies provide a model that accounts for the origin of the enantioselectivity.
- Shi, Jialing,Huang, Yusha,Cai, Qian,Wang, Ting,Zhang, Xinhao,Wu, Yun-Dong
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p. 840 - 843
(2015/04/14)
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- From 2-aminomethyl-1,4-benzodioxane enantiomers to unichiral 2-cyano- and 2-carbonyl-substituted benzodioxanes via dichloroamine
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2-Substituted 1,4-benzodioxanes, such as 2-cyano-, 2-methoxycarbonyl-, 2-aminocarbonyl-, and 2-formyl-1,4-benzodioxane, are key synthons that for the most part are never described as enantiomers or are inadequately characterized for enantiomeric purity. They were prepared by quantitative N,N-dichlorination of (R)- and (S)-2-aminomethyl-1,4-benzodioxane and successive functional group conversions in high yields without any racemization of the stereogenic benzodioxane C(2).
- Bolchi, Cristiano,Valoti, Ermanno,Straniero, Valentina,Ruggeri, Paola,Pallavicini, Marco
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p. 6732 - 6737
(2014/08/05)
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- A facile approach to chiral 1,4-benzodioxane toward the syntheses of doxazosin, prosympal, piperoxan, and dibozane
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The process describes the concise synthesis of (R/S)-enantiomers of doxazosin, an antidepressant drug and α-adrenergic receptor antagonists like prosympal, piperoxan, and dibozane in practical yields from easily available (R)-2,3-O-cyclohexylidene-d-glyce
- Rouf, Abdul,Aga, Mushtaq A.,Kumar, Brijesh,Taneja, Subhash Chandra
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supporting information
p. 6420 - 6422
(2013/11/19)
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- Chemoenzymatic synthesis of piperoxan, prosympal, dibozane, and doxazosin
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The synthesis of both enantiomers of 1,4-benzodioxan-2-carboxylic acid 1, a key synthetic intermediate for the therapeutic agents piperoxan, prosympal, dibozane, and doxazosin was achieved with good yields and high enantioselectivities via the Arthrobacter sp. lipase catalyzed kinetic resolution of ester (±)-17a. The influence of the co-solvents and the immobilization of the lipase upon kinetic resolution demonstrated that immobilized whole cells, in the presence of n-butanol as a co-solvent, resulted in the optimal resolution of the substrate (ee ~99%, E = 535) at 258 mmol (50 g/L) substrate concentration.
- Rouf, Abdul,Gupta, Pankaj,Aga, Mushtaq A.,Kumar, Brijesh,Chaubey, Asha,Parshad, Rajinder,Taneja, Subhash C.
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p. 1615 - 1623
(2013/02/22)
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- PROCESS FOR THE PREPARATION OF CHIRAL 2-HYDROXYMETHYL-1,4-BENZODIOXANE COMPOUND
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The present invention relates to a process for the preparation of chiral 2-hydroxymethyl-l,4-benzodioxane compound. The method in accordance with the present invention comprises the steps of reacting chiral epihalohydrin or chiral glycidyl sulfonate with catechol or its derivative in a presence of a tertiary organic amine or its ammonium salt to carry out an ring opening reaction of the epoxide compound and treating the ring-opened product with an inorganic base to carry out a cyclization reaction of the ring-opened product to prepare the targeted 2-hydroxymethyl-l,4-benzodioxane. The method of the present invention provides the chiral 2-hydroxymethyl-l,4-benzodioxane compound in high optical purity and with improved yield due to reduced side reactions.
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Page/Page column 9
(2008/06/13)
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- Enhancement of the efficiency of the low temperature method for kinetic resolution of primary alcohols by optimizing the organic bridges in porous ceramic-immobilized lipase
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For the enhancement of enantioselectivity and acceleration of the reaction rate in the lipase-catalyzed resolution of primary alcohols, the use of a very low reaction temperature (-30 °C) and an immobilized lipase on organic bridges-coated porous ceramic support was found to be highly effective. Furthermore, the structure of the organic bridges greatly influenced the temperature effect between in E and 1/T as well as the reaction rate. Among the organic bridges examined in the resolution of (±)-2-hydroxymethyl-1,4-benzodioxane, the 6-(2-methylpropanoyloxy)hexylsilanetrioxyl bridge was the best choice for both the E value and the reaction rate at -30 °C.
- Sakai, Takashi,Hayashi, Kyoko,Yano, Fumika,Takami, Mie,Ino, Megumi,Korenaga, Toshinobu,Ema, Tadashi
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p. 1441 - 1446
(2007/10/03)
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- Palladium-catalyzed intramolecular C-O bond formation
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A number of oxygen heterocycles were synthesized using the palladium-catalyzed intramolecular etherification of aryl halides by employing di-tert-butylphosphinobiaryl ligands. The reaction proceeds under mild conditions using weak bases such as Cs2CO3 or K3PO4. A variety of functional groups are tolerated in the reaction, and enantioenriched alcohols can be coupled without erosion of optical purity. The mildness of the reaction conditions allows for the use of polyfunctionalized substrates. This method was used as the key step in the synthesis of MKC-242, an antidepressant currently in clinical trials. The synthesis of MKC-242 was achieved in 40% overall yield from commercially available sesamol and acrylonitrile.
- Kuwabe,Torraca,Buchwald
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p. 12202 - 12206
(2007/10/03)
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- Synthesis of (-)-(S)-2-Hydroxymethyl-2,3-dihydro-1,4-benzodioxine by Enzyme-Catalyzed Resolution of Organic Media
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The chiral primary alcohol 2-hydroxymethyl-2,3-dihydro-1,4-benzodioxine (1) has been resolved by enantioselective acetylation in vinyl acetate solution, using Pseudomonas sp.Amano PS lipase.Enantiomers (-)-S-1 (99percent ee) and (+)-R-1 (72percent ee) were obtained in 45 and 65percent yield, respectively.
- Mauleon, David,Lobato, Cinta,Carganico, Germano
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- Molecular properties of the WB4101 enantiomers and of its chiral methyl derivatives for α1-adrenoceptor recognition
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The optical isomers of the well known α1-antagonist WB4101 and of its derivatives with a methyl group in the oxyethyl moiety were prepared for the evaluation of their α-adrenoceptors binding affinity. By means of a detailed computational analysis, the present work shows that the introduction of a methyl group affects the behaviour of WB4101 in different ways. A limitation of the conformational freedom in certain regions of the torsional subspace of the potential energy function, differences in the reactivity of the protonated species towards a model proton acceptor and the quality of the superposition with the rigid template for α1 antagonists, corynanthine, are examined and discussed in order to select a candidate bioactive form and possible features which act as modulators of the recognition process at the α1-adrenoceptors.
- Villa,Valoti,Villa,Pallavicini,Ferri,Iuliano,Brunello
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p. 587 - 606
(2007/10/02)
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- New 1,4-dihydropyridine derivatives combining calcium antagonism and α-adrenolytic properties
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A series of twelve 1,4-dihydropyridine derivatives incorporating an α-adrenergic moiety in one of the ester chains was synthesized. The compounds were evaluated for their calcium antagonist activities by the inhibition of [3H]nitrendipine bindi
- Marciniak,Delgado,Leclerc,Velly,Decker,Schwartz
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p. 1402 - 1407
(2007/10/02)
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- Serotonergic Properties of Spiroxatrine Enantiomers
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The neuroleptic drug spiperone (1) has proven very useful in the characterization of putative serotonin (5-hydroxytryptamine, 5-HT) receptors.Thus, 5-HT1 receptors have been divided into subtypes based on their affinities for 1: 5-HT1A/su
- Nikam, Sham S.,Martin, Arnold R.,Nelson, David L.
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p. 1965 - 1968
(2007/10/02)
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- SHORT AND ENANTIOSELECTIVE SYNTHESES OF (R)- AND (S)-2-HYDROXYMETHYL-1,4-BENZODIOXAN
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Two straightforward and highly enantioselective syntheses of (R)- and (S)-hydroxymethyl-1,4-benzodioxan from readily available chiral glycidol derivatives are described.
- Delgado, Antonio,Leclerc, Gerard,Lobato, Cinta,Mauleon, David
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p. 3671 - 3674
(2007/10/02)
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- SYNTHESIS OF THE ENANTIOMERS OF ERYTHRO-2-OXIRANYL-1,4-BENZODIOXAN
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(2R,1'S) and (2S,1'R)-2-Oxiranyl-1,4-benzodioxan (2R,1'S-1 and 2S,1'R-1) were prepared in six steps from 2-benzyloxyphenol.The key step in each synthesis was the enantioselective Sharpless epoxidation of allylic alcohol 4.
- Clark, Robin D.,Kurz, Lilia J.
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p. 2005 - 2012
(2007/10/02)
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