- Double-hetero atom six-membered ring of synthetic method
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The invention provides a double-hetero atom six-membered ring of synthetic method. The synthetic method comprises to alkyl substituted cyclopropane and benzyl alcohol and/or a the oxygen radical animal pen is mellow as the starting material, sequentially carry out the ring-opening reaction, a transesterification reaction, 1st sulfonylation reaction, alcoholysis reaction and the nucleophilic substitution reaction, catalytic hydrogenation reaction and 2nd sulfonylation reaction and forming ring reaction, to obtain the required double-hetero atom six-membered ring, a formula (1) of the structure shown. In order to price the comparatively cheap racemic alkyl substituted cyclopropane as raw materials, to participate in the ring-opening reaction, to obtain a ring opening product. Then under the action of the esterase, make the ring-opening products which is a transesterification reaction, disposable obtain the desired racemic compound. This avoids the traditional method of multi-step separation and purification in the synthesis step, shortens the synthetic route. In the above synthetic route also avoids the need to use some dangerous reagent, process more security, reducing waste generation, and save the process cost.
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Paragraph 0110; 0114; 0115; 0116; 0117
(2018/07/30)
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- Piers' borane-mediated hydrosilylation of epoxides and cyclic ethers
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We report the first diarylborane-catalysed hydrosilylation of epoxides and cyclic ethers. Mechanistic studies on the in situ generated Piers' borane (C6F5)2BH with hydrosilanes in the presence of an epoxide revealed that an alkyloxy(diaryl)borane (C6F5)2BOR is readily formed as a catalytically competent species for the outer-sphere hydrosilylation of epoxides and cyclic ethers.
- Zhang, Jianbo,Park, Sehoon,Chang, Sukbok
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supporting information
p. 7243 - 7246
(2018/07/05)
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- A new enantioselective synthesis of the anti-Parkinson agent safinamide
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An alternative highly enantioselective synthesis of the anti-Parkinson agent safinamide from simple, commercially available, starting materials is described. The protocol might also be useful in the synthesis of structural variants of safinamide, such as ralfinamide or related analogues. Georg Thieme Verlag Stuttgart New York.
- Reddi, Anjaneyulu,Mujahid, Mohammad,Sasikumar, Murugesan,Muthukrishnan, Murugan
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p. 1751 - 1756
(2014/07/08)
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- AN IMPROVED SYNTHESIS OF ANTI-PARKINSON AGENT
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The present invention relates to an improved process for synthesis of anti-Parkinson compound of formula (I) from commercially available (R)-benzyl glycidyl ether, wherein the compound obtained has enantiopurity greater than >98%. Formula (I) wherein R1 and R2 are each independently selected from hydrogen or halogen.
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Page/Page column 13
(2014/11/13)
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- Synthesis of (R)-propane-1,2-diol from lactides by dynamic kinetic resolution
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The dynamic kinetic resolution (DKR) of rac-1-tert-butoxypropan-2-ol with isopropenyl acetate in the presence of Novozyme 435 and a ruthenium catalyst produces enantiomerically pure (R)-1-tert-butoxy-2-acetoxy-propane (>99.5 %ee) in a good yield. The product can be easily transformed into (R)-propane-1,2-diol without loss of stereoselectivity. Together with recently published procedures, the herein described DKR offers the possibility to use any lactide source as starting material for the production of (R)-propane-1,2-diol. The chiral diol may serve as the chiral building block for the synthesis of important enantiopure esters, like propylene carbonate, chiral polymers, etc.
- Shuklov, Ivan A.,Dubrovina, Natalia V.,Schulze, Joachim,Tietz, Wolfgang,B?rner, Armin
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p. 3495 - 3497
(2014/06/10)
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- Copper-catalyzed cross-coupling of nonactivated secondary alkyl halides and tosylates with secondary alkyl grignard reagents
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Practical catalytic cross-coupling of secondary alkyl electrophiles with secondary alkyl nucleophiles under Cu catalysis has been realized. The use of TMEDA and LiOMe is critical for the success of the reaction. This cross-coupling reaction occurs via an SN2 mechanism with inversion of configuration and therefore provides a general approach for the stereocontrolled formation of C-C bonds between two tertiary carbons from chiral secondary alcohols.
- Yang, Chu-Ting,Zhang, Zhen-Qi,Liang, Jun,Liu, Jing-Hui,Lu, Xiao-Yu,Chen, Huan-Huan,Liu, Lei
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supporting information; experimental part
p. 11124 - 11127
(2012/08/28)
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- Formation of higher-order structures of chiral poly(ethynylpyridine)s depending on size, temperature, and saccharide recognition
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Amphiphilic 2,6-pyridylene ethynylene "meta-ethynylpyridine" polymers having chiral oligo(oxyethylene) side chains were developed as hosts for saccharide recognition. The polymers were prepared via a Sonogashira reaction and fractionated by gel permeation
- Abe, Hajime,Okada, Kotaro,Makida, Hiroki,Inouye, Masahiko
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p. 6930 - 6936,7
(2012/12/12)
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- Folding of a donor-containing ionene by intercalation with an acceptor
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Cationic ionenes that bear electron-rich 1,5-dialkoxynaphthalene (DAN) units within the alkylene segment were allowed to interact with different types of electron-deficient, acceptor-containing molecules in an effort to realize intercalation-induced folding of the ionenes; the collapse of the chains was expected to occur in such a way that the donor and acceptor units become arranged in an alternating fashion. Several acceptor-bearing molecules were prepared by the derivatization of pyromellitic dianhydride and naphthalene tetracarboxylic dianhydride with two different oligoethylene glycol monomethyl ether monoamines. This yielded acceptor molecules with different water solubility and allowed the examination of solvophobic effects in the folding process. UV/Vis spectroscopic studies were carried out by using a 1:1 mixture of the DAN-ionenes and different acceptor molecules in water/DMSO solvent mixtures. The intensity of the charge-transfer (CT) band was seen to increase with the water content in the solvent mixture, thereby suggesting that the intercalation is indeed aided by solvophobic effects. The naphthalene diimide (NDI) bearing acceptor molecules consistently formed significantly stronger CT complexes when compared to the pyromellitic diimide (PDI) bearing acceptor molecules, which is a reflection of the stronger π-stacking tendency of the former. AFM studies of drop-cast films of different ionene-acceptor combinations revealed that compact folded structures are formed most effectively under conditions in which the strongest CT complex is formed. Know when to fold 'em: When coerced to collapse in a polar solvent in the presence of an electron-deficient amphiphilic folding agent, suitably modified ionenes with a symmetrically positioned electron-rich 1,5-dialkoxylnaphthalene (DAN) unit appear to form an accordion-type folded structure wherein the units are arranged in an alternating fashion (see picture). D=Donor; A=Acceptor. Copyright
- De, Swati,Ramakrishnan
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supporting information; experimental part
p. 149 - 156
(2011/10/08)
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- Identification of absolute helical structures of aromatic multilayered oligo(m-phenylurea)s in solution
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(Chemical Equation Presented) The oligomeric aromatic ureas bearing N,N′-dimethylated urea bonds such as 3 have aromatic multi-layered structure, based on the (cis,cis)-urea structure, and also have dynamic helical structure (all-R or all-S axis chirality) when the benzene rings are connected at the meta positions. The absolute helical structure of oligo(m-phenylurea)s were identified by the empirical and theoretical studies on the CD and vibrational CD (VCD) spectra. Thus, each enantiomer of the oligo(m-phenylurea)s 4 bearing a chiral N-2-(methoxyethoxyethoxy)propyl group were synthesized. Intense dispersion-type CD spectra of 4 were observed, which indicated the induction of handedness in the helical structure. In the VCD spectra of 4 in the film state, the signals due to the carbonyl and aromatic ring vibrations were seen with negative and positive values for compounds 4a and 4b, respectively. The calculations of both CD and VCD spectra of oligo(m-phenylurea)s 3 without any chiral N-substituent gave the same assignment about the axis chirality of 4. Thus, the absolute configurations of 4a and 4b are all-R and all-S structures, respectively. 2009 American Chemical Society.
- Kudo, Mayumi,Hanashima, Takayuki,Muranaka, Atsuya,Sato, Hisako,Uchiyama, Masanobu,Azumaya, Isao,Hirano, Tomoya,Kagechika, Hiroyuki,Tanatani, Aya
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experimental part
p. 8154 - 8163
(2010/02/28)
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- Synthesis of new enantiopure proton-ionizable crown ethers containing a dialkylhydrogenphosphate moiety
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Seven new enantiopure proton-ionizable crown ethers containing a dialkylhydrogenphosphate moiety were prepared starting from optically active dialkyl-substituted oligoethylene glycols and phosphorus oxychloride followed by mild hydrolysis of the resulting macrocyclic chlorophosphates. Pentaethylene glycols having primary hydroxyl groups gave good yields of 17-crown-6 type ethers. Pentaethylene glycols with secondary hydroxyl groups rendered about the same amount of 17-crown-6 ethers and open chain dihydrogenphosphates in low yields. Tetraethylene glycols are reluctant to undergo macrocyclization with phosphorus oxychloride, especially the ones which contain secondary hydroxyl groups.
- Kovacs, Ilona,Huszthy, Peter,Bertha, Ferenc,Sziebert, Denes
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p. 2538 - 2547
(2007/10/03)
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- Process for preparing optically active secondary alcohols having nitrogenous or oxygenic functional groups
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A process for preparing optically active secondary alcohols of the general formula (3), [wherein R1 is linear lower alkyl, an aromatic ring group, or the like; A is CH2NR2R3 or the like; n is an integer of 0 to 2; and * represents an asymmetric carbon atom] by asymmetrically hydrogenating a ketone compound of the general formula (1) having nitrogenous or oxygen functional group at any of the a-, β- and γ-positions, with selectivity among functional groups by the use of a ruthenium/optically active bidentate phosphine/diamine complex as the catalyst in the presence of hydrogen alone or together with a base. The optically active secondary alcohols obtained by the process are useful as drugs and intermediates for the preparation of drugs.
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- Phenoxathiin derivatives as inhibitors of monoamine oxidase
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PCT No. PCT/US97/23486 Sec. 371 Date Mar. 11, 1999 Sec. 102(e) Date Mar. 11, 1999 PCT Filed Aug. 19, 1997 PCT Pub. No. WO98/12190 PCT Pub. Date Mar. 26, 1998The present invention provide phenoxathiin compounds useful in the prophylaxis and treatment of mental disorders, such as depression. The present invention also provides a method for treating a mammal having depression, anxiety or other conditions responsive to inhibition of MAO-A. A method of preparing the compounds of the present invention is also provided.
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- Hierarchical growth of chiral self-assembled structures in protic media
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The location of nine chiral penta(ethylene oxide) side chains at the periphery of a C3-symmetrical hydrogen-bonded extended core gives rise to a thermotropic discotic liquid crystalline material that shows lyotropic phases in polar, protic media. The molecular stacks self-assemble in a reversible and hierarchical fashion, and specific and subtle solvent-molecule interactions together with the created hydrophobic microenvironment account for an unprecedented stabilization of a preferred handedness of the helical stacks by cooperative intermolecular interactions. The presence of either chirality or achirality at the supramolecular level in the stacks can be tuned by temperature and solvent as judged from circular dichroism spectroscopy. A hierarchical growth of the self-assembly is revealed using a variety of spectroscopic techniques and differential scanning calorimetry.
- Brunsveld,Zhang,Glasbeek,Vekemans,Meijer
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p. 6175 - 6182
(2007/10/03)
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- A Raney nickel-sodium hypophosphite combination system for reductive desulfurization without racemization of optically active secondary alcohol
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Sulfides and sulfoxides bearing an optically active secondary alcohol were desulfurized with a Raney nickel (W-2)-sodium hypophosphite combination system to give optically active alcohols in high yields without racemization. However, the combination system was not effective with sulfides which comprise an alkylthio group and the corresponding sulfoxides. This system exhibited the reductive desulfurization of benzylthio or phenylthio other in the presence of a benzyl ether.
- Node, Manabu,Nishide, Kiyoharu,Shigeta, Yukihiro,Obata, Kenichi,Shiraki, Hiroaki,Kunishige, Hideaki
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p. 12883 - 12894
(2007/10/03)
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- Preparation of optically active azophenolic crown ethers containing 1-phenylethane-1,2-diol and 2,4-dimethyl-3-oxapentane-1,5-diol as a chiral subunit: Temperature-dependent enantiomer selectivity in the complexation with chiral amines
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With (2S,4S)-2,4-dimethyl-3-oxapentane-1,5-diol and (S)- or (R)-1-phenylethane-1,2-diol as chiral subunits, optically active azophenolic crown ethers (S,S,S,S)-1, (R,S,S,R)-2, (S,S,S,S)-3 and (R,S,S,R)-4 possessing two phenyl and two methyl substituents together with the p-(2,4-dinitrophenylazo)phenol moiety have been prepared in enantiomerically pure forms. Temperature-dependent enantiomer selectivity in the complexation of these crown ethers with chiral amines has been studied by the UV-visible spectroscopic method in chloroform and from the observed association constants, thermodynamic parameters for the complexation have been calculated.
- Ogasahara, Kazuko,Hirose, Keiji,Tobe, Yoshito,Naemura, Koichiro
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p. 3227 - 3236
(2007/10/03)
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- Reductive desulfurization using the Raney nickel - Sodium hypophosphite combination system without racemization of a secondary alcohol
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Thioethers bearing an optically active secondary alcohol were desulfurized with Raney nickel - sodium hypophosphite - acetate buffer system to give optically active alcohols without racemization in high yields. This Raney nickel combination system exhibited a unique desulfurization of benzylthio or phenylthio group in the presence of benzyl ether.
- Nishide, Kiyoharu,Shigeta, Yukihiro,Obata, Kenichi,Inoue, Takehisa,Node, Manabu
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p. 2271 - 2274
(2007/10/03)
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- The enantiomer ratio strongly depends on the alkyl part of the acyl donor in transesterification with lipase B from Candida antarctica
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Three secondary alcohols, 1-phenoxy-, 1-phenylmethoxy- and 1-(2-phenylethoxy)-2-propanol, have been resolved by transesterification with the acyl donors 2-chloroethyl butanoate, 2,2,2-trichloroethyl butanoate, vinyl butanoate and butanoic anhydride using lipase B from Candida antarctica as catalyst in hexane. The enantiomer rate E, which was calculated on the basis of a ping-pong bi-bi mechanism, was highest when 2-chloroethyl butanoate was used as acyl donor, however the reaction was reversible. It was shown that the E-value increased when the amount of 2,2,2-trichloroethyl butanoate was reduced. It is also indicated that butanoic anhydride and vinyl butanoate make the lipase less specific probably by acylation. Copyright (C) Elsevier Science Ltd.
- Hoff, Bard H.,Anthonsen, Henrik W.,Anthonsen, Thorleif
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p. 3187 - 3192
(2007/10/03)
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- Resolution of 1-phenoxy-, 1-phenylmethoxy- and 1-(2-phenylethoxy)-2-propanol and their butanoates by hydrolysis with lipase B from Candida antarctica
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Resolutions of butanoic esters of 1-phenoxy-2-propanol, 1-phenylmethoxy-2-propanol and 1-(2-phenylethoxy)-2-propanol have been studied with four different lipases as catalysts. Using lipase B from Candida antarctica very high enantiomer ratios were obtained. These substrate-lipase pairs represent an excellent way of getting enantiomerically pure protected 1,2-propanediols in high chemical yield. Copyright (C) Elsevier Science Ltd.
- Hoff, Bard H.,Waagen, Viggo,Anthonsen, Thorleif
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p. 3181 - 3186
(2007/10/03)
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- SYNTHESIS OF ENANTIOMERIC N-(2-PHOSPHONOMETHOXYPROPYL)DERIVATIVES OF PURINE AND PYRIMIDINE BASES. II. THE SYNTHON APPROACH
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Another approach to (R)- and (S)-N-(2-phosphonomethoxypropyl) derivatives of purine and pyrimidine bases (PMP derivatives) I and II is described, consisting in alkylation of the heterocyclic base with (R)- and (S)-2-propyl p-toluenesulfonates (X and XVIII) followed by transsilylation of the intermediary N- derivatives XI and XIX.The key intermediates X and XVIII were obtained from 1-benzyloxypropanols VI and XIV by two routes: (i) condensation with bis(2-propyl) p-toluenesulfonyloxymethylphosphonate (XIII), hydrogenolysis of the obtained 1-benzyloxy-2-bis(2-propyl)phosphonylmethoxypropanes VIII and XVI over Pd/C to 2-bis(2-propyl)phosphonylmethoxypropanols IX and XVII and tosylation of the latter or (ii) chloromethylation of compounds VI and XIV and subsequent reaction of the chloromethyl ethers VII and XV with tris(2-propyl) phosphite and further processing of the benzyl ethers VIII and XVI analogous to the enantiomeric propanols IX and XVII.This approach was used for the synthesis of derivatives of adenine (Ia, IIa), 2,6-diaminopurine (Ib, IIb) and 3-deazaadenine (Ic, IIc).Their guanine counterparts Ie and IIe were prepared by hydrolysis of 2-amino-6-chloropurine intermediates XId and XIXd. 6-Chloropurine was converted into diester XIi by reaction with tosylate X, which on reaction with thiourea and subsequent ester cleavage afforded the 6-thiopurine derivative Ij.Analogously, 2-amino-6-chloropurine derivative XId reacted with thiourea to give 9-(R)-(2-phosphonomethoxypropyl)-2-thioguanine (If), or with dimethylamine under formation of (2-phosphonomethoxypropyl)-2-amino-6-dimethylaminopurine (Ig).Hydrogenolysis of compound XId gave 9-(R)-(2-phosphonomethoxypropyl)-2-aminopurine (Ik).Hydrolytic deamination of adenine derivatives Ia and IIa led to enantiomeric (2-phoshonomethoxypropyl)hypoxanthines Ih and IIh.
- Holy, Antonin,Dvorakova, Hana,Masojidkova, Milena
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p. 1390 - 1409
(2007/10/02)
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- Preparation and Enantiomer Recognition of Chiral Azophenolic Crown Ethers Having three Chiral Barriers on each of the Homotopic Faces
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Homochiral azophenolic crown ethers 1 and 2 having three chiral barriers, that is, the phenyl group, the methyl group, and the cyclohexane moiety on each of the homotropic faces have been prepared.The enantiomer recognition toward chiral 2-aminoethanol derivatives has been examined.
- Naemura, Koichiro,Asada, Masaki,Hirose, Keiji,Tobe, Yoshito
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p. 1873 - 1876
(2007/10/03)
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- Stereoselectivity of Baker's yeast reduction of 2-propanones: influence of substituents.
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The stereoselectivity of Baker's yeast reduction of prochiral alpha-oxygenated 2-propanones has been studied by varying the substrate structure. The 1-hydroxy-3-methoxy-3-propanone 1a was reduced to the corresponding alcohol (R)-2a with 88% enantiomeric excess. Replacing the hydroxy group in 1a with phenoxy or benzyloxy (1b and 1c) gave the alcohols (S)-2b and (S)-2c with 53 and 32% ee, respectively. Reduction of the methyl ketone 1d gave the alcohol (S)-2d with 91% ee. Attempts to improve the enantioselectivity of the reduction of 1c by lowering the substrate concentration or addition of selective reductase inhibitors had only small effect on the enantioselectivity.
- Waagen,Partali,Hollingsaeter,Huang,Anthonsen
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p. 506 - 510
(2007/10/02)
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- A new synthesis of (S)-β-methyl-γ-butyrolactone and (S)-4-benzyloxy-3-methylbutanoic acid
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A stereoselective synthesis of (S)-β-methyl-γ-butyrolactone [(S)-4,5-dihydro-4-methyl-2(3H)-furanone, 1] and of (S)-4-benzyloxy-3-methylbutanoic acid (2) is described. Both compounds are prepared starting from inexpensive L-ethyl lactate with overall yields of 26% and 30%, respectively. The products are valuable chiral building blocks.
- Berens,Scharf
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p. 832 - 834
(2007/10/02)
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- Optically active-2-alkoxy-propyl ether and liquid crystal composition
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An optically active substance which, when added as a component of ferroelectric liquid crystal compositions, is extremely small in the reduction of the resulting liquid crystal temperature region, and a liquid crystal composition containing the same are provided, which substance is an optically active-2-alkoxy-propyl ether expressed by the formula (I) STR1 wherein R1 represents a straight or branched chain alkyl, alkoxy, alkanoyl, alkanoyloxy or alkoxycarbonyl each of 1 to 18 C; R2 represents a linear or branched chain alkyl each of 1 to 15 C; --A-- represents a specified group constituted by two directly bonded, six-membered rings; and * indicates asymmetric carbon atom.
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- Stereochemically Controlled Bakers'-Yeast-Mediated Reductions: Synthesis of (S)-(+)-1,2-Propanediol and (S)-(-)-1,3-Butanediol, 1-Benzyl Ethers
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Benzyloxyketones 1a and b can be reduced by fermenting bakers' yeast to the corresponding protected (S)-diols 2a and b in 76 and 52percent yields, respectively (90 and >95percent e.e., respectively, as (R)-(+)-MTPA esters).
- Manzocchi, Ada,Fiecchi, Alberto,Santaniello, Enzo
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p. 1007 - 1009
(2007/10/02)
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- Stereoselective Synthesis of 1- and 2-O-α-D-Cellotriosyl-3-deoxy-2(R)- and 2(S)-glycerols Related to Rhynchosporoside
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The stereoselective synthesis of 1- and 2-O-α-D-cellotriosyl-3-deoxy-2(R)- and 2(S)-glycerols, which determined the structure of rhynchosporoside produced by Rhynchosporium secalis, and their phytotoxicity toward the host plant (Hordeum vulgare) are described in detail.
- Sugawara, Fumio,Nakayama, Haruhiko,Stroebel, Gary A.,Ogawa, Tomoya
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p. 2261 - 2272
(2007/10/02)
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- Stereochemical Evidence for Pseudorotation in the Reaction of a Phosphoric Monoester
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The phosphoro group of 2-phosphoropropane-1,2-diol migrates to the 1-position on heating in aqueous acid.This migration occurs by two routes.The direct route is belived to proceed via a pentacoordinate intermediate that must, by Westheimer's rules, pseudo
- Buchwald, Stephen L.,Pliura, Diana H.,Knowles, Jeremy R.
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p. 4916 - 4922
(2007/10/02)
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