- Synthesis and characterization of benzo- and naphtho[2,1-b:3,4-b′] dithiophene-containing oligomers for photovoltaic applications
-
Dicyanovinyl (DCV) end-capped oligomers 1-7 containing fused benzo[2,1-b:3,4-b′]dithiophene (BDT) and naphtho[2,1-b:3,4-b′] dithiophene (NDT) as central cores have been synthesized and characterized. These oligomers show excellent thermal stability due to the insertion of the central fused ring system thus allowing purification by gradient sublimation in high yield. With respect to the reference compound, non-fused tetramer DCV4T, the new oligomers showed hypsochromic shifts in absorption and emission spectra and larger band gaps in thin films. Due to high lying LUMO energy levels, they exhibit sufficient energy offset with respect to C60 to allow for efficient charge transfer in organic solar cells. At the same time, low-lying HOMO energy levels result in high open-circuit voltages (VOC). As a result, planar heterojunction (PHJ) solar cells derived from the novel oligomers and C60 provide very high open circuit voltages (VOC) of up to 1.21 V and power conversion efficiencies (PCEs) of up to 2.7%. Bulk-heterojunction (BHJ) devices comprising oligomers 1-4 and C60 display a slightly lower VOC of 1 V leading to efficiencies as high as 3.6%. This journal is the Partner Organisations 2014.
- Loebert, Mirjam,Mishra, Amaresh,Uhrich, Christian,Pfeiffer, Martin,Baeuerle, Peter
-
-
Read Online
- Preparation of N-nitrohydroxylamines by the substituting nitration method
-
N-Nitro-N-methyl-O-substituted hydroxylamines were synthesized in high yields by nitration of appropriate N-acetylhydroxylamines with nitrogen pentoxide.
- Khodot,Petrova,Anikin,Chlenov
-
-
Read Online
- One-pot method for preparing O-alkyl hydroxylamine hydrochloride and N,O-dialkyl hydroxylamine hydrochloride
-
The invention relates to the field of organic synthesis, in particular to a one-pot method for preparing O-alkyl hydroxylamine hydrochloride and N,O-dialkyl hydroxylamine hydrochloride. The method comprises the following steps: S1, acetylation: mixing hydroxylamine hydrochloride with water and methyl acetate, and dropwise adding a sodium hydroxide solution while stirring at room temperature to obtain an intermediate acetyl hydroxylamine; S2, alkylation: dropwise adding an alkylation reagent into the reaction kettle at normal temperature, and then heating the reactants for reaction; S3, hydrolysis and purification: after the reaction is qualified, adding concentrated sulfuric acid, performing heating hydrolysis, after the reaction is qualified, adding caustic soda flakes or liquid caustic soda to adjust the pH value to 12, carrying out atmospheric distillation and hydrochloric acid acidification, cooling the product for crystallization, and centrifuging and drying the crystal to obtaina final product. According to the invention, methyl acetate is used as an acetyl protective agent, and compared with ethyl acetate, methyl acetate has the advantages of good water solubility, small reaction steric hindrance, sufficient protection, few impurities, low price and cost and the like; therefore, the method has the advantages of high product purity, simple process operation, accessible raw materials, simple wastewater components and environment friendliness, and is suitable for industrial production.
- -
-
Paragraph 0032-0033
(2020/10/20)
-
- Asymmetric Construction of Alkaloids by Employing a Key ω-Transaminase Cascade
-
An ω-transaminase-triggered intramolecular aza-Michael reaction has been employed for the preparation of cyclic β-enaminones in good yield and excellent enantio- and diastereoselectivity, starting from easily accessible prochiral ketoynones and commercially available enzymes. The powerful thermodynamic driving force associated with the spontaneous aza-Michael reaction effectively displaces the transaminase reaction equilibrium towards product formation, using only two equivalents of isopropylamine. To demonstrate the potential of this methodology, this biocatalytic aza-Michael step was combined with annulation chemistry, affording unique stereo-defined fused alkaloid architectures.
- Taday, Freya,Ryan, James,Argent, Stephen P.,Caprio, Vittorio,Maciá, Beatriz,O'Reilly, Elaine
-
supporting information
p. 3729 - 3732
(2020/03/11)
-
- Expedient Pd-Catalyzed α-Arylation towards Dibenzoxepinones: Pivotal Manske's Ketone for the Formal Synthesis of Cularine Alkaloids
-
The general synthesis of diversely substituted dibenzoxepinones by a combined Pd-catalyzed α-arylation and SNAr strategy is reported and applied to the synthesis of Manske's ketone, a key intermediate en route to the total synthesis of cularine alkaloids. In the course of this work, an unanticipated ring contraction reaction to a xanthone was observed and serves as a caveat for the conditions of the widely used α-arylation reaction.
- Deichert, Julie A.,Mizufune, Hideya,Patel, Jignesh J.,Hurst, Timothy E.,Maheta, Ashish,Kitching, Matthew O.,Ross, Avena C.,Snieckus, Victor
-
supporting information
p. 4693 - 4697
(2020/05/08)
-
- Formation of Aryl [1-Cyano-4-(dialkylamino)butadienyl] Ketones from Pyridines
-
Treatment of 2-chloropyridine with LDA and the Weinreb amide of benzoic acid afforded three unusual products, namely N -methylbenzamide, 2-chloropyridine-3-methanol, and the ring-opened addition product. This same final product could also be obtained from 2-chloro-3-benzoylpyridine on treatment with LDA. Mechanistic insight for the formation of these products is provided.
- Gim, Hyo Jin,Jung, Michael E.
-
supporting information
p. 2548 - 2552
(2019/06/08)
-
- Synthesis of Enantiomerically Pure β-Hydroxy Ketones via β-Keto Weinreb Amides by a Condensation/Asymmetric-Hydrogenation/Acylation Sequence
-
An established route to enantiomerically pure β-hydroxy ketones proceeds through the asymmetric hydrogenation of β-keto esters, an ester/amide exchange, and the use of the resulting β-hydroxy amide for the acylation of an organometallic compound. We shortened this route by showing that β-keto Weinreb amides are hydrogenated with up to 99 % ee in the presence of [Me2NH2]+{[RuCl(S)-BINAP]2(μ-Cl)3}–(0.5 mol-%) at room temp./5 bar. These Weinreb amides were prepared by seemingly obvious yet unprecedented condensations of lithiated N-methoxy-N-methylacetamide with carboxylic chlorides (51–87 % yield). The resulting β-hydroxy Weinreb amides were used for the acylation of organolithium and Grignard reagents. They thus gave enantiomerically pure β-hydroxy ketones (28 examples). A selection of these compounds gave anti-1,3-diols after another C=O bond hydrogenation, or syn-1,3-diols by a Narasaka–Prasad reduction.
- Diehl, Julian,Brückner, Reinhard
-
supporting information
p. 278 - 286
(2017/01/24)
-
- Light-Activated Sensitive Probes for Amine Detection
-
Our new, simple, and accurate colorimetric method is based on diarylethenes (DAEs) for the rapid detection of a wide range of primary and secondary amines. The probes consist of aldehyde- or ketone-substituted diarylethenes, which undergo an amine-induced decoloration reaction, selectively to give the ring-closed isomer. Thus, these probes can be activated at the desired moment by light irradiation, with a sensitivity that allows the detection of amines at concentrations as low as 10?6m in solution. In addition, the practical immobilization of DAEs on paper makes it possible to detect biogenic amines, such as cadaverine, in the gas phase above a threshold of 12 ppbv within 30 seconds.
- Valderrey, Virginia,Bonasera, Aurelio,Fredrich, Sebastian,Hecht, Stefan
-
supporting information
p. 1914 - 1918
(2017/02/05)
-
- Pyrrole inhibitors of S-nitrosoglutathione reductase as therapeutic agents
-
The present invention is directed to inhibitors of S-nitrosoglutathione reductase (GSNOR), pharmaceutical compositions comprising such GSNOR inhibitors, and methods of making and using the same.
- -
-
Page/Page column 301
(2015/11/16)
-
- AUTOTAXIN INHIBITOR COMPOUNDS
-
Described herein are compounds that are autotaxin inhibitors, methods of making such compounds, pharmaceutical compositions and medicaments comprising such compounds, and methods of using such compounds in the treatment of conditions, diseases, or disorders associated with autotaxin activity.
- -
-
Paragraph 00439
(2015/04/15)
-
- Modified shapiro reactions with bismesitylmagnesium as an efficient base reagent
-
Bismesitylmagnesium has been shown to successfully mediate the Shapiro reaction. A range of tosylhydrazones has been subjected to the developed system, which furnishes exceptionally high incorporation of the introduced electrophiles and good yields of the functionalized styrenes. At conveniently accessible temperatures and with a comparably small excess of base reagent, this protocol offers an efficient alternative to the lithium-mediated process. Importantly, 1.05 equiv of Weinreb amides are sufficient to obtain aryl enones in good yields.
- Kerr, William J.,Morrison, Angus J.,Pazicky, Marek,Weber, Tina
-
supporting information; experimental part
p. 2250 - 2253
(2012/06/30)
-
- Sn/Li exchange reactions in 1,ω-distannylated conjugated trienes and tetraenes: An enabling step for polyene synthesis
-
Successive treatments of (1E,3E,5E)- or (1E,3Z,5E)-1,6-bis(tributylstannyl) hexa-1,3,5-triene with nBuLi and butanal rendered polyenyl alcohols resulting from one Sn/Li exchange reaction and exhibiting complete retention of the configuration of all C=C bonds. Mono- or dimethylated all-E-configured 1,6-distannylated conjugated trienes as well as all-E-1,8-bis(tributylstannyl) octa-1,3,5,7-tetraene and dimethylated congeners thereof reacted similarly. The respective Sn/Li exchange reactions affected the substructure Bu 3Sn-CH=CH with a 93-94:7-6 preference over Bu3Sn-CMe=CH and with a 90:10 preference over Bu3Sn-CH=CMe. all-E-1-Lithio-6- (tributylstannyl)hexa-1,3,5-triene was incorporated into navenone B after Negishi coupling and into (-)-cicutoxin after acylation. NMR spectroscopy of our navenone B specimen revealed that certain resonances were misassigned previously. Molecular tinkertoy: all-E-1,6-(Tributylstannyl)hexa-1,3,5-triene, all-E-1,8-(tributylstannyl)octa-1,3,5,7-tetraene, and related bis(tributylstannylated) polyenes undergomono-Sn/Li exchange reactions. They set the stage for terminus-differentiating functionalizations, which provide inter alianavenone B and (-)-cicutoxin.
- Burghart, Jochen,Brueckner, Reinhard
-
experimental part
p. 150 - 165
(2011/03/18)
-
- Catalytic enantioselective construction of β-quaternary carbons via a conjugate addition of cyanide to β,β-disubstituted α,β-unsaturated carbonyl compounds
-
The first general catalytic enantioselective conjugate addition of cyanide to β, β-disubstituted α,β-unsaturated ketones and N-acylpyrroles was developed using a strontium catalyst derived from Sr(O iPr)2 and new chiral ligand 5. The reaction exhibited excellent enantioselectivity and a wide substrate scope using 0.5-10 mol % catalyst. 1,4-Adducts containing β-quaternary carbons were exclusively produced over 1,2-adducts. ESI-MS analysis of the strontium catalyst indicated that the active catalyst was a trimetallic Sr/5 = 3:5 complex. The exclusive 1,4-selectivity was partly due to the ability of the strontium complex to promote both a retro-cyanation reaction from the 1,2-adducts and highly enantioselective conjugate cyanation.
- Tanaka, Yuta,Kanai, Motomu,Shibasaki, Masakatsu
-
supporting information; experimental part
p. 8862 - 8863
(2010/08/21)
-
- A facile synthesis of 2,3-disubstituted furo[2,3-b]pyridines
-
In a three-step sequence starting from readily available starting materials, 2,3-carbon disubstituted furo[2,3-b]pyridines can be accessed in good yields and purity. Furo[2,3-b]pyridines bearing ester, amide and ketone groups at the 2-position can be prepared with a variety of aryl and alkyl groups at the 3-position.
- Beutner, Gregory L.,Kuethe, Jeffrey T.,Yasuda, Nobuyoshi
-
supporting information; experimental part
p. 781 - 784
(2009/05/11)
-
- POLYMORPHS OF A HYDROISOINDOLINE TACHYKININ RECEPTOR ANTAGONIST
-
This application is directed to a novel polymorph of a hydroisoindoline tachykinin receptor antagonist having the following structural formula A.
- -
-
Page/Page column 15-16
(2008/12/05)
-
- 4-(Isoxazol-3-yl)pyrimidines from pyrimidinyl nitrile oxides
-
The 1,3-dipolar cycloaddition reaction of pyrimidinylaldoxime derived nitrile oxides and alkynes delivers 4-(isoxazol-3-yl)pyrimidines. The procedures reported accommodate three points of diversification around this bisheterocyclic scaffold and the resulting library of compounds has been added to the National Institutes of Health repository (ca. 10 mg of each with >90% purity) for pilot-scale biomedical studies with bioassay data available at the National Center for Biotechnology Information PubChem database. Georg Thieme Verlag Stuttgart.
- Choung, Wonken,Lorsbach, Beth A.,Sparks, Thomas C.,Ruiz, James M.,Kurth, Mark J.
-
experimental part
p. 3036 - 3040
(2009/06/25)
-
- Process for making hydroisoindoline tachykinin receptor antagonists
-
The present invention is directed to a process for preparing certain hydroisoindoline compounds which are useful as neurokinin-1 (NK-1) receptor antagonists, and inhibitors of tachykinin and in particular substance P. The compounds are useful in the treatment of certain disorders, including emesis, urinary incontinence, depression, and anxiety.
- -
-
Page/Page column 8; 9
(2008/06/13)
-
- Highly flexible and efficient synthesis of the GABAB enhancer 4-(2-hexylsulfanyl-6-methyl-pyrimidin-4-ylmethyl)-morpholine
-
In the course of establishing a flexible synthesis of 2,4,6-substituted pyrimidines, we discovered that 2-hexyl-isothiourea hydrobromide reacts at ambient temperature and in a mildly exothermic fashion with 5,5-diethoxy-pent-3-yn-2-one upon treatment with 2 equiv of triethylamine in tetrahydrofuran to afford 4-diethoxymethyl-2-hexylsulfanyl-6-methyl-pyrimidine in 80% isolated yield. The methodology was developed in the search for an improved synthesis of the GABAB enhancer 4-(2-hexylsulfanyl-6-methyl-pyrimidin-4-ylmethyl)-morpholine.
- Verron, Julien,Malherbe, Paricher,Prinssen, Eric,Thomas, Andrew W.,Nock, Nadine,Masciadri, Raffaello
-
p. 377 - 380
(2007/10/03)
-
- A facile one-pot synthesis of acyclic β-enamino ketones, an important class of versatile synthetic intermediates
-
A one-pot sequential process consisting of nucleophilic substitution of the lithiated acetylides with Weinreb amides followed by a Michael reaction of the extruded N-methoxy-N-methylamine after quenching with saturated NH4Cl, provided β-enamino ketones in high yield and in a single geometrical isomeric form. It has been demonstrated that this method is applicable to a wide variety of such amides and to different acetylides.
- Choudhury, Anusuya,Breslav, Michael,Grimm, Jeffrey S.,Xiao, Tong,Xu, Dawei,Sorgi, Kirk L.
-
p. 3069 - 3072
(2008/02/02)
-
- Hydroxylated nebivolol metabolites
-
Hydroxylated nebivolol metabolites increase NO release from human endothelial cell preparations in a concentration dependent fashion following acute administration. In addition, hydroxylated nebivolol metabolites, including but not limited to 4-hydroxy-6,6′difluoro-, 4-hydroxy-5-phenol-6,6′difluoro-, and 4-hydroxy-8-pheno-6,6′difluoro-, have the ability to increase the capacity for NO release in human endothelial cells following chronic administration. This invention provides hydroxylated nebivolol metabolites and compositions comprising nebivolol and/or at least one hydroxylated metabolite of nebivolol and/or at least one additional compound used to treat cardiovascular diseases or a pharmaceutically acceptable salt thereof. In addition, this invention provides methods of treating and/or preventing vascular diseases by administering at least one hydroxylated metabolite of nebivolol that is capable of releasing a therapeutically effective amount of nitric oxide to a targeted site affected by the vascular disease. Also, this invention is directed to the treatment and/or prevention of migraine headaches administering at least one hydroxylated metabolite of nebivolol. This invention may also be used in conjunction with or as a single treatment of metabolic syndrome disorders.
- -
-
-
- Solution- and solid-phase synthesis of radicicol (monorden) and pochonin C
-
A modular synthesis for pochonin C and radicicol is reported. The two natural products were prepared in seven and eight steps, respectively, from three readily available fragments. Alternative syntheses of these compounds were achieved using a combination of polymer-bound reagents and solid phase reactions. The conformation of the two natural products was studied and compared by using 2D NMR spectroscopy.
- Barluenga, Sofia,Moulin, Emilie,Lopez, Pilar,Winssinger, Nicolas
-
p. 4935 - 4952
(2007/10/03)
-
- Aminomethylpyrimidines as allosteric enhancers of the GABAB receptors
-
The present invention relates to compounds of formula whereinX is —S— or —NH—; R3/R4 together with the N-atom to which they are attached form a non aromatic 5, 6 or 7 membered ring, which optionally contains in addition to the N-atom one additional heteroatom selected from the group consisting of O, S and N, and wherein the ring is optionally substituted by hydroxy, lower alkyl, lower alkoxy, —NR2, —CONR2, —CO-lower alkyl or benzyl; or R3/R4 form together with the N-atom to which they are attached a heterocyclic ring system, containing two or three rings and which optionally contains one or two additional heteroatoms selected from the group consisting of N and O and which has no more than 20 carbon atoms; and R, R1, R2, and R5 are as defined herein and to pharmaceutically suitable acid addition salts thereof. It has been found that the compounds of the invention are active on the GABAB receptor and therefore are useful for the treatment of anxiety, depression, epilepsy, schizophrenia, cognitive disorders, spasticity and skeletal muscle rigidity, spinal cord injury, multiple sclerosis, amyotrophic lateral sclerosis, cerebral palsy, neuropathic pain and craving associated with cocaine and nicotine, psychosis, panic disorder, posttraumatic stress disorders and gastro-intestinal disorders.
- -
-
Page/Page column 10
(2010/02/13)
-
- 4- (SULFANYL-PYRIMIDIN-4-YLMETHYL) -MORPHOLINE DERIVATIVES AND RELATED COMPOUNDS AS GABA RECEPTOR LIGANDS FOR THE TREATMENT OF ANXIETY, DEPRESSION AND EPILEPSY
-
The present invention relates to compounds of Formula (I) wherein X is-S-or-NH-; R1 is alkyl, alkenyl, arylalkyl, arylalkenyl or aryl-O-alkyl, wherein the aryl groups are optionally substituted by one or more substituents, selected from the group consisting of lower alkyl, lower alkoxy, halogen or lower halogen-alkyl; R2 is hydrogen, lower alkyl or cycloalkyl; R3 /R4 may form together with the N-atom to which they are attached a non aromatic5, 6 or 7 membered ring, which may contain in addition to the N-atom one additional heteroatom selected from the group consisting of O, S or N, and wherein the ring is optionally substituted by hydroxy, lower alkyl, lower alkoxy,-NR2,-CONR2,-CO-lower alkyl or benzyl; or may form together with the N-atom to which they are attached a heterocyclic ring system, containing at least two rings and which may contain one or two additional heretoatoms, selected from the group consisting of N or O; R is hydrogen or lower alkyl; R5 is hydrogen or lower alkyl; and to pharmaceutically suitable acid addition salts thereof. It has been found that the compounds are active on the GABAB receptor and therefore useful for the treatment of anxiety, depression, epilepsy, schizophrenia, cognitive disorders, spasticity and skeletal muscle rigidity, spinal cord injury, multiple sclerosis, amyotrophic lateral sclerosis, cerebral palsy, neuropathic pain and craving associated with cocaine and nicotine, psychosis, panic disorder, posttraumatic stress disorders or gastro-intestinal disorders.
- -
-
Page/Page column 19
(2010/02/14)
-
- Structure of disilylated acetoacetohydroxamic acid
-
As proved by 29Si and 15N NMR spectra, the reaction of N,O-bis(trimethylsilyl)hydroxylamine with diketene yields a mixture of E and Z isomers of O,O′-bis(trimethylsilyl)acetoacetohydroximic acid ((E)-3 and (Z)-3), and not the conformers of N,O-bis(trimethylsilyl)acetoacetohydroxamic acid (1), as believed up to now. In contrast, the acetylation of N,O-dimethylhydroxylamine leads to methyl N-methylacetohydroxamate (5), analogous to the structure 1.
- Schraml, Jan,Hetflejs, Jiri,Sabata, Stanislav,Blechta, Vratislav,Sykora, Jan,Roithova, Jana
-
p. 1472 - 1478
(2007/10/03)
-
- Preparation of 4-trifluoroethylidene-1,3-dioxolane derivatives via new stable (trifluoromethyl)ethynylation reagent
-
Perfluoroalkylated 4-trifluoroethylidene-1,3-dioxolane derivatives 2a-q were prepared in excellent yields from the reaction of new stable (trifluoromethyl)ethynylation reagent 1a with 1.3 equiv. of TBAF at -15°C for 10 min, followed by treatment with 2 equiv. of phenyl perfluoroalkylated ketone derivatives at room temperature. The reaction of 1a with 1.3 equiv. of TBAF, followed by treatment with 1 equiv. of aldehyde or ketone at -15°C for 10 min and then with trifluoroacetophenone (1 equiv.) at room temperature afforded perfluoroalkylated 4-trifluoroethylidene-1,3-dioxolane derivatives 2t-u in moderate yields.
- Jeong, In Howa,Jeon, Sung Lan,Kim, Bum Tae
-
p. 7213 - 7216
(2007/10/03)
-
- Process for the manufacture of hypoxyxylerone derivatives
-
The present invention relates to the total synthesis of hypoxyxylerone derivatives (formula I) and their biological activities. R1-R5 are as described in the description.
- -
-
-
- Synthesis of Quinolines and 2H-Dihydropyrroles by Nucleophilic Substitution at the Nitrogen Atom of Oxime Derivatives
-
Isomerization of oxime derivatives was researched in detail to find out the methods for the syn-anti isomerization of O-substituted oximes. Based on these findings were developed simple methods for the preparation of aza-heterocycles from both stereoisomers of oximes. Quinolines were synthesized from β-aryl ketone oximes by treatment with trifluoroacetic anhydride and 4-chloranil. γ,δ-Unsaturated O-methoxyacetyloximes were transformed to 2H-dihydropyrroles by reaction with methoxy-acetic acid.
- Kitamura, Mitsuru,Yoshida, Masayuki,Kikuchi, Takashi,Narasaka, Koichi
-
p. 2415 - 2426
(2007/10/03)
-
- Dihydroimidazo[2,1-b]thiazole and dihydro-5h-thiazolo[3,2-A]pyrimidines as antidepressant agents
-
The present invention relates to certain novel substituted dihydroimidazo[2,1-b]thiazole and dihydro-5H-thiazolo[3,2-a]pyrimidine compounds of Formula (I) including pharmaceutically acceptable salts thereof in which have affinity for 5-HT1A receptors and which inhibits neuronal reuptake of 5-hydroxytryptamine and/or noradrenaline, to processes for their preparation, to pharmaceutical compositions containing them and to their use in the treatment of depression, anxiety, psychoses (for example schizophrenia), tardive dyskinesia, obesity, drug addiction, drug abuse, cognitive disorders, Alzheimer's disease, obsessive-compulsive behaviour, panic attacks, social phobias, eating disorders such as bulimia, anorexia, snacking and binge eating, non-insulin dependent diabetes mellitus, hyperglycaemia, hyperlipidaemia, stress, as an aid to smoking cessation and in the treatment and/or prophylaxis of seizures, neurological disorders such as epilepsy and/or in which there is neurological damage such as stroke, brain trauma, cerebral ischaemia, head injuries and haemorrhage.
- -
-
-
- DIBAL-H-H2NR and DIBAL-H-HNR1R2·HCl complexes for efficient conversion of lactones and esters to amides
-
The reaction of a lactone or an ester with organoaluminum species generated from DIBAL-H-H2NR or DIBAL-H-HNR1R2·HCl complexes provided efficient methods for preparation of amides. Conditions were defined for the preparation of both secondary and tertiary amides, including Weinreb amides in excellent yields.
- Huang, Pei-Qiang,Zheng, Xiao,Deng, Xian-Ming
-
p. 9039 - 9041
(2007/10/03)
-
- Process for producing substituted amines and a method for purifying synthetic intermediates therefor
-
The present invention relates to a process for producing a substituted amine represented by the general formula (IV): (wherein R2 represents a hydrogen atom, a hydrocarbon group or a heteroatom-containing hydrocarbon group, and R3 represents a hydrocarbon group or a heteroatom-containing hydrocarbon group), which comprises the steps of: (b) reacting a hydroxamic acid represented by the general formula (II): (wherein R1 represents a hydrogen atom or a hydrocarbon group) in the presence of a base with a reaction reagent capable of introducing a hydrocarbon or a heteroatom-containing hydrocarbon group to an oxygen atom and/or a nitrogen atom to form a substituted hydroxamic acid represented by the general formula (III): STR1 (wherein R1, R2 and R3 possess the same meanings as defined above), (c) hydrolyzing said substituted hydroxamic acid (III) in the presence of a base or an acid to produce a substituted amine represented by the general formula (IV): (wherein R2 and R3 possess the same meanings as defined above). The present further relates to a method for purifying a synthetic intermediate for said substituted amine.
- -
-
-
- The sydnone ring as an ortho-director of lithiation. 2. Dilithiation of 3-phenylsydnone and regiospecific @?o-aryl acylation using N-methoxy-N-methylamides
-
Readily available 3-phenylsydnone (1) reacts with n-butyllithium/TMEDA to form the dilithio species 2 which can be regiospecifically acylated at the ortho-aryl position using N-methoxy-N-methylamides (Weinreb's amides).
- Turnbull, Kenneth,Sun, Congcong,Krein, Douglas M.
-
p. 1509 - 1512
(2007/10/03)
-
- Ozonolyses of O-alkylated ketoximes in the presence of carbonyl groups: A facile access to ozonides
-
Ozonolyses of O-methyl oximes of acyclic ketones (7, 10, 19) and of cyclic ketones (16, 24, 27, 31) in the presence of acyclic ketones (8, 9, 17) or of cyclic ketones (18, 25, 26, 31) gave the corresponding tetrasubstituted cross-ozonides (13, 21, 29, 32). Ozonolyses of O-methylated monooximes of 1,4-, 1,5-, and 1,6-dicarbonyl compounds (35b-f) gave the corresponding bicyclic ozonides 36b-f. VCH Verlagsgesellschaft mbH, 1997.
- Griesbaum, Karl,Liu, Xuejun,Kassiaris, Athanassios,Scherer, Martin
-
p. 1381 - 1390
(2007/10/03)
-
- Diozonides from coozonolyses of suitable O-methyl oximes and ketones
-
Ozonolyses of the O-methyl oximes of cyclic ketones 5a - c in the presence of 1,4-cyclohexanedione (6) and ozonolyses of the O-methylated dioxime 8 of 1,4-cyclohexanedione in the presence of cycloketones 7a - c afforded the corresponding diozonides 11. Ozonolysis of the O-methyl oxime of acetone gave diozonide 18 in the presence of 6 and diozonide 21 in the presence of butanedione. Ozonolysis of the O-methyl oxime of cyclohexanone in the presence of butanedione gave diozonide 22. In addition, representatives of the hitherto unknown types of dispiro ozonides 12 having a lactam ring system have been obtained from the ozonolyses of 8 and 7.
- Griesbaum, Karl,Liu, Xuejun,Dong, Yuxiang
-
p. 5463 - 5470
(2007/10/03)
-
- -
-
The microbioloaical reduction of 3.A-diketones has been studied and some optically pure 3-hydroxy-4-ketones and 3,4-diols have been isolated with good yields. The chiral products of the reduction, which could not be obtained by direct action of microorganisms, were prepared by chemoenzymatic synthesis based on the microbiological reduction of a-ketothioacetals. The stereomers of non-8-ene-3,4-dials obtained by these methods were used for synthesizing the enantiomers of two pheromones: exo-fcreuzcomm and cndo-brevicomin. Eisevier,.
- Bel-Rhlid, Rachid,Renard, Michel F.,Veschambre, Henri
-
p. 1011 - 1021
(2007/10/03)
-
- AMIDE O-ALKYLOXIMES AND THEIR REACTIONS WITH ALKYLATING AGENTS
-
Amide O-alkyloximes are formed with high yields in the reaction of the hydrochlorides of unsubstituted amidines with O-alkylhydroxyamines.Their reactions with alkyl halides, dimethyl sulfate, and triethyloxonium fluoroborate lead to the corresponding salts of N-alkoxy-N-alkylamidines.
- Martynov, B. I.,Zhestkov, S. A.,Martynov, I. V.
-
-
- MICROBIOLOGICAL SYNTHESIS OF VARIOUSLY PROTECTED L-GLYCERALDEHYDES IN HIGH OPTICAL PURITY
-
Variously protected L-glyceraldehydes have been enantioselectively synthesized through a sequence involving acylation of formylanion equivalents with glycolic acid derivatives followed by baker's yeast mediated reduction of the resulting ketones.
- Guanti, Giuseppe,Banfi, Luca,Narisano, Enrica
-
p. 3547 - 3550
(2007/10/02)
-
- ACETYLATIONS OF STRONGLY BASIC AND NUCLEOPHILIC ENOLATE ANIONS WITH N-METHOXY-N-METHYLACETAMIDE
-
Efficient acetylation of the multiple anions of poly-β-carbonyl compounds is achieved by the use of N-methoxy-N-methylacetamide.
- Oster, Timothy A.,Harris, Thomas M.
-
p. 1851 - 1854
(2007/10/02)
-