- Enantioselective Copper(I)/Chiral Phosphoric Acid Catalyzed Intramolecular Amination of Allylic and Benzylic C?H Bonds
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Radical-involved enantioselective oxidative C?H bond functionalization by a hydrogen-atom transfer (HAT) process has emerged as a promising method for accessing functionally diverse enantioenriched products, while asymmetric C(sp3)?H bond amination remains a formidable challenge. To address this problem, described herein is a dual CuI/chiral phosphoric acid (CPA) catalytic system for radical-involved enantioselective intramolecular C(sp3)?H amination of not only allylic positions but also benzylic positions with broad substrate scope. The use of 4-methoxy-NHPI (NHPI=N-hydroxyphthalimide) as a stable and chemoselective HAT mediator precursor is crucial for the fulfillment of this transformation. Preliminary mechanistic studies indicate that a crucial allylic or benzylic radical intermediate resulting from a HAT process is involved.
- Ye, Liu,Tian, Yu,Meng, Xiang,Gu, Qiang-Shuai,Liu, Xin-Yuan
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p. 1129 - 1133
(2019/12/12)
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- Selective carboxylation of reactive benzylic C–H bonds by a hypervalent iodine(III)/inorganic bromide oxidation system
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An oxidation system comprising phenyliodine(III) diacetate (PIDA) and iodosobenzene with inorganic bromide, i.e., sodium bromide, in an organic solvent led to the direct introduction of carboxylic acids into benzylic C–H bonds under mild conditions. The unique radical species, generated by the homolytic cleavage of the labile I(III)–Br bond of the in situ-formed bromo-λ3-iodane, initiated benzylic carboxylation with a high degree of selectivity for the secondary benzylic position.
- Dohi, Toshifumi,Iwasaki, Kosuke,Kita, Yasuyuki,Morimoto, Koji,Tsunoda, Yusuke,Ueda, Shohei
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p. 1087 - 1094
(2020/05/06)
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- Preparation method for hemihydrate lorcaserin hydrochloride
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The invention discloses a preparation method for hemihydrate lorcaserin hydrochloride. The preparation method comprises the following steps: (1) making a compound shown as a formula III react with ammonia to obtain a compound shown as a formula II; (2) under the protection of nitrogen gas, dissolving the compound shown as the formula II in an organic solvent, adding a hydrogen chloride solution of which the solvent is the organic solvent to salify, and adding water and cyclohexane to form a hemihydrate in order to obtain the compound shown as a formula I, wherein the organic solvent is isopropanol or 1,4-dioxane. In the preparation method disclosed by the invention, ammonium hydroxide substitutes for potassium carbonate in the prior art, so that unqualified ignition residues of a finial product caused by potassium chloride generated after salt removal can be avoided; an isopropoxide hydrochloride solution substitutes for the conventional hydrogen chloride gas, so that other impurities can be prevented from being introduced in a preparation process under the improper control of dosage and rate of the gas.
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Paragraph 0133; 0134
(2017/08/28)
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- A mild and highly chemoselective iodination of alcohol using polymer supported DMAP
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The synthesis of organic compounds using polymer supported catalysts and reagents, where the required product is always in solution, has been of great interest in recent years, both in industries and academia especially in pharmaceutical research. Here, a simple and efficient method for conversion of alcohols into their iodides in high yield using polymer supported 4-(Dimethylamino)pyridine (DMAP) is described. Polymer supported DMAP is used in catalytic amount and is recovered and reused several times. Additionally, this method is highly chemoselective. [Figure not available: see fulltext.]
- Das, Diparjun,H Anal, Jasha Momo,Rokhum, Lalthazuala
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p. 1695 - 1701
(2017/03/08)
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- Diamino triazines derivatives, their salts, preparation method, composition and use thereof
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The invention discloses derivatives and salts of damino dihydrotriazine, and a preparation method, a composition and application thereof. According to the invention, the preparation method of the damino dihydrotriazine derivative and the damino dihydrotriazine salt can be realized by adopting a method I or a method II, wherein the method I includes the step of obtaining a general formula I compound prepared through the reaction between a general formula IV compound and a general formula V compound, while the method II includes the step of mixing a general formula VIII compound with a general formula II compound under an acidic condition, and obtaining the compound shown in the general formula I through a cyclization reaction of the mixture. The invention also provides application of derivatives and salts of the damino dihydrotriazine in preparation of human dihydrofolate reductase inhibitors, preventing and curing drugs for tumor or bacterial infection diseases. The invention further provides a drug composition, which comprises an effective amount of the derivatives and/or salts of the damino dihydrotriazine, as well as pharmaceutically acceptable carriers. According to the invention, spiro heterocyclic ring derivatives of the damino dihydrotriazine have an excellent inhibitory activity on human dihydrofolate reductase, tumor cells and bacteria.
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Paragraph 0193; 0194; 0195
(2016/10/07)
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- Scalable anti-Markovnikov hydrobromination of aliphatic and aromatic olefins
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To improve access to a key synthetic intermediate we targeted a direct hydrobromination-Negishi route. Unsurprisingly, the anti-Markovnikov addition of HBr to estragole in the presence of AIBN proved successful. However, even in the absence of an added initiator, anti-Markovnikov addition was observed. Re-examination of early reports revealed that selective Markovnikov addition, often simply termed "normal" addition, is not always observed with HBr unless air is excluded, leading to the rediscovery of a reproducible and scalable initiator-free protocol.
- Galli, Marzia,Fletcher, Catherine J.,Del Pozo, Marc,Goldup, Stephen M.
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supporting information
p. 5622 - 5626
(2016/07/06)
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- An examination of the effects of borate group proximity on phosphine donor power in anionic (phosphino)tetraphenylborate ligands
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The ligand electron-donating abilities are compared among a series of monodentate, anionic (phosphino)tetraphenylborate phosphines [Ph4P][Ph2P-R-C6H4BPh3] (R = -C6H4-, -CH2-, -CH2CH2- or none), and their neutral counterparts Ph2PR (R = biphenyl, -CH2Ph, -CH2CH2Ph or Ph). Among the anionic ligands, the position of the tetraphenylborate group relative to the diphenylphosphino donor moiety was systematically varied in an effort to examine how its proximity impacts donor power. The donor power was determined by measuring the 31P-77Se coupling constant for the corresponding selenide of each phosphine ligand via 31P NMR spectroscopy. The anionic ligands yield lower 31P-77Se coupling constants than those measured for their respective neutral counterparts. Moreover, the 31P-77Se coupling constants among the anionic ligands increase when the tetraphenylborate group is positioned further from the phosphorus centre.
- Tassone, Joseph P.,Mawhinney, Robert C.,Spivak, Gregory J.
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supporting information
p. 153 - 156
(2015/02/19)
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- Indium(III)-catalyzed one-pot synthesis of alkyl cyanides from carboxylic Acids
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The one-pot preparation of alkyl cyanides from carboxylic acids via alkyl iodides or alkyl bromides, which were in situ generated either by indium(III)-catalyzed reductive iodination or bromination of carboxylic acids, is described. Georg Thieme Verlag Stuttgart New York.
- Moriya, Toshimitsu,Shoji, Kohei,Yoneda, Shinichiro,Ikeda, Reiko,Konakahara, Takeo,Sakai, Norio
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p. 3233 - 3238
(2013/12/04)
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- Indium-catalyzed reductive bromination of carboxylic acids leading to alkyl bromides
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The combination of 1,1,3,3-tetramethyldisiloxane (TMDS) and trimethylbromosilane (Me3SiBr) with a catalytic amount of indium bromide (InBr3) undertook direct bromination of carboxylic acids, which produced the corresponding alkyl bromides in good to excellent yields. The reducing system was tolerant to several functional groups.
- Moriya, Toshimitsu,Yoneda, Shinichiro,Kawana, Keita,Ikeda, Reiko,Konakahara, Takeo,Sakai, Norio
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supporting information
p. 4842 - 4845,4
(2020/09/16)
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- Synthesis, biochemical evaluation and rationalisation of the inhibitory activity of a range of 4-substituted phenyl alkyl imidazole-based inhibitors of the enzyme complex 17α-hydroxylase/17,20-lyase (P45017α)
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We report the preliminary results of the synthesis, biochemical evaluation and rationalisation of the inhibitory activity of a number of phenyl alkyl imidazole-based compounds as inhibitors of the two components of 17α-hydroxylase/17,20-lyase (P45017α), that is, 17α-hydroxylase (17α-OHase) and 17,20-lyase (lyase). The results show that N-3-(4-bromophenyl) propyl imidazole (12) (IC50 = 2.95 μM against 17α-OHase and IC50 = 0.33 μM against lyase) is the most potent compound within the current study, in comparison to ketoconazole (KTZ) (IC50 = 3.76 μM against 17α-OHase and IC50 = 1.66 μM against lyase). Modelling of these compounds suggests that the length of the alkyl chain enhances the interaction between the inhibitor and the area of the active site corresponding to the C(3) area of the steroid backbone, thereby increasing potency.
- Patel, Chirag H.,Dhanani, Sachin,Owen, Caroline P.,Ahmed, Sabbir
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p. 4752 - 4756
(2007/10/03)
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- Aminoalcohol derivatives
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The present invention relates to a compound formula[I]: wherein X is bond, —CH2—, —O— or —NH—, R1 and R12 are each independently hydrogen, halogen, lower alkyl, etc., R2 is hydrogen or optionally substituted lower alkyl, R3 is hydrogen or an amino protective group, R4, R5 and R6 are each independently hydrogen or optionally substituted lower alkyl, R7 is -Z-R13, in which Z is bond, etc., and R13 is carboxy, lower alkoxycarbonyl, (lower alkylsulfonyl)carbamoyl or lower alkanoylsulfamoyl, R8 is —Y—R9, in which Y is bond, —CH2—, —O—, —S—, etc., and R9 is hydrogen, lower alkyl, cyclo(lower)alkyl, etc., and R11 is hydrogen, lower alkyl, lower alkoxy, etc., or a salt thereof. The compound [I] of the present invention and pharmaceutically acceptable salts thereof are useful for the prophylactic and/or the therapeutic treatment of pollakiurea or urinary incontinence.
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Page/Page column 20
(2010/02/12)
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- NEW 2-SUBSTITUTED, 4-AMINO-THIAZOLO[4,5-D] PYRIMIDINES, USEFUL AS CHEMOKINE RECEPTOR ANTAGONISTS, ESP. CX3CR1
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There are disclosed novel compounds of formula (I) wherein A, R1, R2, R3 and X are as defined in the specification, and pharmaceutically acceptable salts thereof, together with processes for their preparation, pharmaceutical compositions comprising them and their use in therapy. The compounds of formula (I) are CX3CR1 receptor antagonists and are thereby particularly useful in the treatment or prophylaxis of neurodegenerative disorders, demyelinating disease, atherosclerosis and pain.
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Page/Page column 29-30
(2010/02/11)
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- Indoles
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A 1,4-substituted cyclic amine derivative represented by the following formula or a pharmacologically acceptable salt thereof: wherein A, B, C, D, T, Y, and Z each represent a methine or a nitrogen linkage; R1, R2, R3, R4, and R5 each represent a substituent; n represents 0 or an integer of 1 to 3; m represents 0 or an integer of 1 to 6; and p represents an integer of 1 to 3. The compounds have serotonin antagonism. They are therefore clinically useful as medicaments, in particular, for treating, ameliorating, and preventing spastic paralysis. They are also useful as central muscle relaxants for ameliorating myotonia.
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- M-AMIDINO PHENYL ANALOGS AS FACTOR Xa INHIBITORS
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The present application describes m-amidino phenyl analogs of formula (I), wherein D can be amidino and E can be phenyl, which are useful as inhibitors of factor Xa.
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- α-branched anilines, toluenes, and analogs thereof as factor Xa inhibitors
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The present application describes m-amidino phenyl analogs of formula I: wherein D can be amidino and E can be phenyl, which are useful as inhibitors of factor Xa.
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- Mild and fast deoxygenation of aromatic carbonyl compounds by dimethylamine borane/titanium tetrachloride
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The title reaction proceeds in dichloromethane at room temperature within 1/2 hour. Benzylic alcohols are intermediates. TiCl4 can be replaced by other (although less effective) Lewis acids such as AlCl3, BF3·ether, FeCl3.
- Dehmlow, Eckehard V.,Niemaiin, Thomas,Kraft, Ante
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p. 1467 - 1472
(2007/10/03)
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- Influence of Solvent Polarity on the Radiationless Decay of the Intramolecular Exciplexes of ω-Phenyl-α-N,N-dimethylaminoalkanes
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Using optoacoustic spectroscopy, the radiationless decay processes of intramolecular exciplexes of ω-phenyl-α-N,N-dimethylaminoalkanes are investigated.Upon increase of the solvent polarity, the relative efficiency of the intersystem crossing process from the singlet exciplex to the locally excited triplet decreases compared to the efficiency of the internal conversion process.These results can be rationalized in the framework of the current electron-transfer theory and compared to the results obtained for other ω-aryl-α-N,N-dimethylaminoalkanes.
- Auweraer, M. Van der,Viaene, L.,Haver, Ph. Van,Schryver, F. C. De
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p. 7178 - 7184
(2007/10/02)
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- ALKOXYNITRENIUM ION CYCLISATIONS: EVIDENCE FOR DIFFERENT MECHANISMS IN THE FORMATION OF BENZOXAZINES AND BENZOXAZEPINES.
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Deuterium labelling experiments and n.m.r. studies indicate that cyclisations of N-acyl-N-(2-phenylethyloxy)nitrenium ions occur via direct attack at the ortho position to give 3,4-dihydro-1H-2,1-benzoxazines.In contrast N-acyl-N-(3-phenylpropyloxy)nitrenium ions cyclise to 1,3,4,5-tetrahydro-2,1-benzoxazepines through ipso attack followed by 1,2-carbon migration.In both cases hydrogen circumambulation occurs in the sigma complex before aromatisation.
- Glover, Stephen A.,Rowbottom, Colleen A.,Scott, Anthony P.,Schoonraad, Johan L.
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p. 7247 - 7262
(2007/10/02)
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