- Vicinal difluorination as a C=C surrogate: An analog of piperine with enhanced solubility, photostability, and acetylcholinesterase inhibitory activity
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Piperine, a natural product derived from peppercorns, has a variety of biological activities that make it an attractive lead compound for medicinal chemistry. However, piperine has some problematic physicochemical properties including poor aqueous solubility and a susceptibility to UV-induced degradation. In this work, we designed an analog of piperine in which the central conjugated hydrocarbon chain is replaced with a vicinal difluoroalkane moiety. We show that this fluorinated analog of piperine has superior physicochemical properties, and it also has higher potency and selectivity towards one particular drug target, acetylcholinesterase. This work highlights the potential usefulness of the threo-difluoroalkane motif as a surrogate for E-alkenes in medicinal chemistry.
- Lizarme-Salas, Yuvixza,Ariawan, Alexandra Daryl,Ratnayake, Ranjala,Luesch, Hendrik,Finch, Angela,Hunter, Luke
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Read Online
- The development of novel cytochrome P450 2J2 (CYP2J2) inhibitor and the underlying interaction between inhibitor and CYP2J2
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Human Cytochrome P450 2J2 (CYP2J2) as an important metabolic enzyme, plays a crucial role in metabolism of polyunsaturated fatty acids (PUFAs). Elevated levels of CYP2J2 have been associated with various types of cancer, and therefore it serves as a potential drug target. Herein, using a high-throughput screening approach based on enzymic activity of CYP2J2, we rapidly and effectively identified a novel natural inhibitor (Piperine, 9a) with IC50 value of 0.44 μM from 108 common herbal medicines. Next, a series of its derivatives were designed and synthesised based on the underlying interactions of Piperine with CYP2J2. As expected, the much stronger inhibitors 9k and 9l were developed and their inhibition activities increased about 10 folds than Piperine with the IC50 values of 40 and 50 nM, respectively. Additionally, the inhibition kinetics illustrated the competitive inhibition types of 9k and 9l towards CYP2J2, and K i were calculated to be 0.11 and 0.074 μM, respectively. Furthermore, the detailed interaction mechanism towards CYP2J2 was explicated by docking and molecular dynamics, and our results revealed the residue Thr114 and Thr 315 of CYP2J2 were the critical sites of action, moreover the spatial distance between the carbon atom of ligand methylene and Fe atom of iron porphyrin coenzyme was the vital interaction factor towards human CYP2J2.
- Tian, Xiangge,Zhou, Meirong,Ning, Jing,Deng, Xiaopeng,Feng, Lei,Huang, Huilian,Yao, Dahong,Ma, Xiaochi
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p. 737 - 748
(2021/03/16)
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- An Ir3L2complex with anion binding pockets: photocatalyticE-Zisomerizationviamolecular recognition
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A molecular host with photosensitizing centers provides photo-responsive host-guest properties based on its molecular recognition ability. Here, we construct a self-assembled photoactive Ir(iii) cage-shaped complex that contains anion binding pockets on its rim. The anion recognition ability of the complex enables efficient catalysis of the visible-light-inducedE-Zisomerization of an anionic styrene derivative.
- Sunohara, Haruka,Koyamada, Kenta,Takezawa, Hiroki,Fujita, Makoto
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supporting information
p. 9300 - 9302
(2021/09/20)
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- Identification and optimization of piperine analogues as neuroprotective agents for the treatment of Parkinson's disease via the activation of Nrf2/keap1 pathway
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Parkinson's disease (PD) is a slowly progressive and complex neurodegenerative disorder. Up to date, there are no approved drugs that could slow or reverse the neurodegenerative process of PD. Here, we reported the synthesis of series of piperine analogues and the evaluation of their neuroprotective effects against hydrogen peroxide (H2O2) induced damage in the neuron-like PC12 cells. Among these analogues, 3b exhibited the most potent protection effect and its underlying mechanism was further investigated. Further results indicated that the ROS scavenging and cytoprotection effect of 3b might be related to the Nrf2 activation and upregulation of related phase II antioxidant enzymes, such as HO-1 and NQO1. In in vivo study, oral administration (100 mg/kg) of 3b significantly attenuated PD-associated behavioral deficits in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced mouse model of PD and protected tyrosine hydroxylase-immunopositive dopaminergic neurons. Our results provided evidence that 3b might be a promising candidate for Parkinson's disease treatment.
- Cai, Xiaoying,Chen, Lijuan,Hong, Feng,Kuang, Shuang,Li, Yan,Ma, Xu,Qi, Wenyan,Shi, Mingsong,Wang, Lun,Xu, Ruiling,Xue, Linlin,Ye, Haoyu,Zhang, Ruijia
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- Piperine derivative as well as preparation method and application thereof
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The invention provides a piperine derivative as well as a preparation method and an application thereof. The piperine derivative is a compound shown as a formula (I), or a salt thereof, or a stereoisomer thereof, or a hydrate thereof. The compound provided by the invention can effectively protect nerve cells and improve the survival rate of the nerve cells, so that the compound provided by the invention can effectively treat neurodegenerative diseases and can be used for preparing medicines for treating the neurodegenerative diseases.
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Paragraph 0142; 0178-0184
(2020/05/08)
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- A Short, Efficient, and Stereoselective Synthesis of Piperine and its Analogues
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A quantitative synthesis of piperine from commercially available starting material is presented. The synthesis relies on a stereoselective nucleophilic attack of an in situ generated cuprate onto a cyclobutene lactone. The so-formed aryl-substituted cyclobutene spontaneously undergoes a conrotatory 4π-electrocyclic ring opening to form the 4-aryl pentadienoic acid as a single diastereoisomer. The high-yielding synthesis can be easily modulated on the aryl and on the amide moiety for the synthesis of a wide range of piperine analogues.
- Bauer, Adriano,Nam, Jun-Hyun,Maulide, Nuno
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p. 413 - 416
(2019/02/26)
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- Piperine synthesis method
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The invention discloses a piperine synthesis method. According to the synthesis method, 5-(1,2-methylenedioxyphenyl)-2-pentenal is taken as the primary raw material; a palladium catalyst is used, oxygen is taken as the oxidizing agent, trifluoroacetic acid is taken as the additive, in a polar organic solvent, one-step oxidation-dehydrogenation is performed to obtain 5-(1,2-methylenedioxyphenyl)-2,4-dipentenal, then oxidation and amidation are carried out to obtain piperine, and the yield is high. The key step namely palladium is used to catalyze oxidation-dehydrogenation is realized, and piperine can be synthesized efficiently and concisely. Compared with a conventional method, the operation is simple, the reaction yield is higher, the method is environmentally friendly, the yield is high,and the atom utilization rate is high.
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Paragraph 0009; 0012; 0016; 0017
(2019/11/28)
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- PROCESS FOR THE PREPARATION OF PIPERINE
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The present application relates to a process for the preparation of piperine of high purity having low concentrations of isomeric impurities.
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Page/Page column 9; 15; 17
(2019/05/02)
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- Synthesis, antimicrobial, antioxidant and nematicidal activity of (2E,4E)-5-(Benzo[d] [1,3]dioxol-5yl)penta-2,4-dienamides
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The amides of piperic acid have been synthesized via the condensation of piperic acid with amines. The structural characterization was done by IR, 1H-NMR, EI-MS and elemental analysis. The amides 3a-3o were evaluated for their biological activity. It has been found that among others the newly synthesized compound 3f, 3k, 3m, and 3o have great potential against root-knot nematode Meloidogyne incognita that usually affect tomato crop. These compounds exhibited 92, 96, 82 and 95% mortality rate at lethal concentration (LC50) 4.4, 3.4, 4.5 and 3.5 mg/mL, respectively. Conventionally used nematicide furadan was taken as standard. Compound 3h, 3c and, 3j exhibited significant anti-oxidant activities against 1,1-diphenylpicrylhydrazil (DPPH) radical with 80, 70 and 72% inhibition (EC50 = 625, 937 and 937.5 μg/mL), respectively. Ascorbic acid was used as standard. When tested for antimicrobial activity 3m was found to be the most active one showing zone of inhibition in the range of 18-30 mm against all tested microbial strains. Good biological activities of synthetic amides indicate their ability to behave as a good antimicrobial and nematicidal agent.
- Wahab, Aneela,Sultana, Amina,Khan, Khalid Mohammed,Sherwani, Sikandar K.,Perveen, Zeba,Taha, Muhammad,Karim, Aneela
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p. 1008 - 1014
(2016/01/12)
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- A metal-free approach for transamidation of amides with amines in aqueous media
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An efficient, environmentally benign and a mild protocol for transamidation of amides with a variety of amines in the presence of K2S2O8 using stoichiometric quantity in aqueous conditions has been established. This method works under conventional thermal conditions and in microwave irradiation as well. A series of amides have been prepared using this reaction and this is a greener protocol for transamidation, which offers a diverse kind of substrate scope with exclusive product formation (yields 90-98%).
- Srinivas, Mahesuni,Hudwekar, Abhinandan D.,Venkateswarlu, Vunnam,Reddy, G. Lakshma,Kumar, K. A. Aravinda,Vishwakarma, Ram A.,Sawant, Sanghapal D.
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supporting information
p. 4775 - 4779
(2015/07/20)
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- Efficient modulation of γ-aminobutyric acid type a receptors by piperine derivatives
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Piperine activates TRPV1 (transient receptor potential vanilloid type 1 receptor) receptors and modulates γ-aminobutyric acid type A receptors (GABAAR). We have synthesized a library of 76 piperine analogues and analyzed their effects on GABAAR by means of a two-microelectrode voltage-clamp technique. GABAAR were expressed in Xenopus laevis oocytes. Structure-activity relationships (SARs) were established to identify structural elements essential for efficiency and potency. Efficiency of piperine derivatives was significantly increased by exchanging the piperidine moiety with either N,N-dipropyl, N,N-diisopropyl, N,N-dibutyl, p-methylpiperidine, or N,N-bis(trifluoroethyl) groups. Potency was enhanced by replacing the piperidine moiety by N,N-dibutyl, N,N-diisobutyl, or N,N-bistrifluoroethyl groups. Linker modifications did not substantially enhance the effect on GABAAR. Compound 23 [(2E,4E)-5-(1,3-benzodioxol-5-yl)-N,N-dipropyl-2,4-pentadienamide] induced the strongest modulation of GABAA (maximal GABA-induced chloride current modulation (IGABA-max = 1673% ± 146%, EC 50 = 51.7 ± 9.5 μM), while 25 [(2E,4E)-5-(1,3-benzodioxol- 5-yl)-N,N-dibutyl-2,4-pentadienamide] displayed the highest potency (EC 50 = 13.8 ± 1.8 μM, IGABA-max = 760% ± 47%). Compound 23 induced significantly stronger anxiolysis in mice than piperine and thus may serve as a starting point for developing novel GABA AR modulators.
- Sch?ffmann, Angela,Wimmer, Laurin,Goldmann, Daria,Khom, Sophia,Hintersteiner, Juliane,Baburin, Igor,Schwarz, Thomas,Hintersteininger, Michael,Pakfeifer, Peter,Oufir, Mouhssin,Hamburger, Matthias,Erker, Thomas,Ecker, Gerhard F.,Mihovilovic, Marko D.,Hering, Steffen
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supporting information
p. 5602 - 5619
(2014/08/05)
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- Sulfur monoxide transfer from peri -substituted trisulfide-2-oxides to dienes: Substituent effects, mechanistic studies and application in thiophene synthesis
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Three peri-substituted trisulfide-2-oxides are prepared by treatment of 1,8-naphthalene dithiols with thionyl chloride and pyridine. The 1,2,3-trithiane-2-oxide ring adopts a sofa conformation in the solid state, with a pseudoaxial oxygen and evidence of ring strain (peri-interaction). Heating the trisulfide-2-oxides in the presence of a diene results in formal sulfur monoxide (SO) transfer to form unsaturated cyclic sulfoxides, along with a recyclable 1,8-naphthalene disulfide. The presence of o-methoxy or o-tert-butyl substituents on the naphthalene ring lowers the temperature and increases the rate at which SO transfer occurs. Trapping experiments and kinetic studies are consistent with the generation of triplet SO, followed by in situ trapping by diene. Transfer of SO also occurs upon irradiation at room temperature, but yields of sulfoxide are lower. Dehydration of the sulfoxides under Pummerer conditions gives thiophenes, including the naturally occurring thioperillene. Two dienes form thiophenes directly under the SO transfer conditions. The methodology is applied in a formal synthesis of the antiplatelet medication Plavix.
- Grainger, Richard S.,Patel, Bhaven,Kariuki, Benson M.,Male, Louise,Spencer, Neil
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supporting information; experimental part
p. 5843 - 5852
(2011/06/22)
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- Chromatography-free wittig reactions using a bifunctional polymeric reagent
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The first example of a polystyrene bearing two distinct reagent groups has been prepared. This phosphine and amine functionalized material was used in one-pot Wittig reactions with an aldehyde and either an α-halo-ester, -ketone, or -amide. Due to the heterogeneous nature of the polymer, the desired alkene product of these reactions could be isolated in excellent yield in essentially pure form after only filtration and solvent removal.
- Leung, Peter Shu-Wai,Teng, Yan,Toy, Patrick H.
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supporting information; experimental part
p. 4996 - 4999
(2010/12/25)
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- Kinetics of light-induced cis-trans isomerization of four piperines and their levels in ground black peppers as determined by HPLC and LC/MS
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The pungent compounds piperine and isomers thereof, secondary metabolites present in black and white pepper fruit, undergo light-induced isomerizations. To facilitate studies in this area, an HPLC method has been developed for analysis and isolation of the following four possible piperine-derived photoinduced isomers: piperine, isopiperine, chavicine, and isochavicine. The limits of detection (LOD) estimated from calibration plots were ~15-30 ng for each isomer. Reproducibilities of the analyses were excellent, and recoveries of spiked samples were as follows (average ± SD; n = 3): chavicine, 98.4 ± 2.1%; isopiperine, 96.2 ± 3.2%; piperine, 104 ± 3.8%; isochavicine, 98.9 ± 3.0%. To determine the kinetics of these isomerizations, fluorescent light, sunlight, and UV radiation at 254 nm was used to induce cis-trans geometric isomerization as a function of light intensities and time of exposure determined with the aid of high-performance liquid chromatography (HPLC) and liquid chromatography with diode array UV detection-mass spectrometry (LC-DAD/MS). HPLC was also used to determine the distribution of the isomers in four commercial ground black pepper products used as spices in culinary practice. Isomerization increased with light intensities and time of exposure and leveled off at the so-called photostationary phases. The piperine levels of the four products were quite similar, ranging (in wt %) from 10.17 to 11.68. The amounts of the other three isomers ranged from 0.01 to 0.07 of the total for chavicine; from 0.15 to 0.23 for isopiperine; and from 0.37 to 0.42 for isochavicine. The results establish the utility of the HPLC method for simultaneous analysis of the four isomers both in pure form and in black pepper extracts. The dietary significance of the results is discussed.
- Kozukue, Nobuyuki,Park, Mal-Sun,Choi, Suk-Hyun,Lee, Seung-Un,Ohnishi-Kameyama, Mayumi,Levin, Carol E.,Friedman, Mendel
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p. 7131 - 7139
(2008/09/17)
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- UV irradiation affects melanocyte stimulatory activity and protein binding of piperine
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Piperine, the major alkaloid of black pepper (Piper nigrum L.; Piperaceae), stimulates melanocyte proliferation and dendrite formation in vitro. This property renders it a potential treatment for the skin depigmentation disorder vitiligo. However, piperine does not stimulate melanin synthesis in vitro, and treatments based on this compound may therefore be more effective with concomitant exposure of the skin to ultraviolet (UV) radiation or sunlight. The present study investigated the effect of UVA and simulated solar radiation (SSR) on the chemical stability of piperine, its melanocyte stimulatory effects and its ability to bind protein and DNA. Chromatographic and spectroscopic analysis confirmed the anticipated photoisomerization of irradiated piperine and showed the absence of any hydrolysis to piperinic acid. Isomerization resulted in the loss of ability to stimulate proliferation of a mouse melanocyte cell line, and to bind to human serum albumin. There was no evidence of DNA binding by piperine either before or after irradiation, showing the absence of photoadduct formation by either piperine or its geometric isomers. This is unlike the situation with psoralens, which form DNA adducts when administered with UVA in treating skin diseases. The present study suggests that exposure to bright sunlight should be avoided both during active application of piperine to the skin and in the storage of piperine products. If UVA radiation is used with piperine in the treatment of vitiligo, application of the compound and irradiation should be staggered to minimize photoisomerization. This approach is shown to effectively induce pigmentation in a sparsely pigmented mouse strain.
- Soumyanath, Amala,Venkatasamy, Radhakrishnan,Joshi, Meghna,Faas, Laura,Adejuyigbe, Bimpe,Drake, Alex F.,Hider, Robert C.,Young, Antony R.
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p. 1541 - 1548
(2008/02/12)
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- Stereoselective synthesis of naturally occurring unsaturated amide alkaloids by a modified Ramberg-Baecklund reaction
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A convenient and rapid approach for the synthesis of naturally occurring unsaturated amide alkaloids 1a-1n by the recently developed one-flask Ramberg-Baecklund reaction is described. The starting material was alcohol 3, which was transformed into thiolacetate 4 using the Mitsunobu reaction. In situ cleavage of acetyl moiety of 4, followed by alkylation of the resulting thiol with appropriate chloroacetamide 5, provided the sulfide 6. Oxidation of sulfide 6 gave the corresponding sulfone 2. Treatment of the sulfone 2 with the dibromodifluoromethane in the presence of alumina-supported potassium hydroxide in dichloromethane solution afforded unsaturated amide alkaloids 1a-1n. To the best of our knowledge, the synthesis of 1e and 1i was reported for the first time.
- Li, Yang,Zhang, Yu,Huang, Zhi,Cao, Xiaoping,Gao, Kun
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p. 622 - 630
(2007/10/03)
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- Process for extraction of piperine from piper species
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The present invention relates to a process for extraction of piperine of Formula I from the fruits of Piper species, comprising the steps of: contacting the fruit of piper species with aqueous hydrotrope solution at a temperature in the range of 0-100° C. and separating the solution from the solid residue by known methods, and recovering piperine from the solution by known methods.
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- Three-component synthesis of (E)-α,β-unsaturated amides of the piperine family
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Selective formation of (E)-α,β-unsaturated amides by intermolecular three-component reaction between aldehydes, amines (1° or 2°) and ketenylidenetriphenylphosphorane (Ph3P=C=C=O) is described. Natural amides such as fagaramide and piperines could be prepared from immediately available educts. The method is shown to be extendable to the preparation of thioesters from thiols and aldehydes.
- Schobert,Siegfried,Gordon
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p. 2393 - 2397
(2007/10/03)
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- Addition of carbon nucleophiles to aldehyde tosylhydrazones of aromatic and heteroaromatic-compounds: Total synthesis of piperine and its analogs
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Addition of carbon nucleophiles to aldehyde tosylhydrazones of aromatic and heteroaromatic compounds is reported. New observations have been made wherein alkylative reduction is observed in some cases whereas alkylative fragmentation is noticed in others. These findings are exploited in the synthesis of the useful alkaloid piperine and its analogs. (C) 2000 Elsevier Science Ltd.
- Chandrasekhar,Venkat Reddy,Srinivasa Reddy,Ramarao
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p. 2667 - 2670
(2007/10/03)
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- Catalytic Hunsdiecker reaction and one-pot catalytic Hunsdiecker-Heck strategy: Synthesis of α,β-unsaturated aromatic halides, α- (dihalomethyl)benzenemethanols, 5-aryl-2,4-pentadienoic acids, dienoates and dienamides
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The reaction of α,β-unsaturated aromatic (or heteroaromatic) carboxylic acids with N-halosuccinimides (1 equiv.) and catalytic tetrabutylammonium trifluoroacetate (0.2 equiv.) in dichloroethane results in facile halodecarboxylation affording the corresponding (E)-halides in good to excellent yields. A similar reaction, but with 2 equiv. of N-halosuccinimides in acetonitrile-water (1:1 v/v) results in the exclusive formation of the corresponding α-(dihalomethyl)benzenemethanols. Furthermore, a one-pot strategy has been developed combining catalytic Hunsdiecker reaction (using tetrabutylammonium trifluoroacetate in dichloroethane) and Heck coupling (using palladium acetate/triethylamine/triphenylantimony/dichloroethane) for the synthesis of 5-aryl-2,4-pentadienoic acids, esters and amides in moderate to good yields. The natural product piperine and pipergualamine has been synthesized via the above route. Mechanistic and theoretical studies (via AM1 calculations) provide a useful insight into the mechanism of the present halodecarboxylation reaction, suggesting an ionic pathway involving the attack of the halogenium ion across the carbon-carbon double bond, triggering the elimination of carbon dioxide. (C) 2000 Elsevier Science Ltd.
- Naskar, Dinabandhu,Roy, Sujit
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p. 1369 - 1377
(2007/10/03)
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- A synthetic approach to natural dienamides of insecticidal interest
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An efficient synthesis of dienamides of insecticidal interest has been stereoselectively achieved featuring a Stille cross-coupling reaction as the key step.
- Abarbri, Mohamed,Parrain, Jean-Luc,Duchene, Alain
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p. 239 - 249
(2007/10/03)
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- Is metal necessary in the Hunsdiecker-Borodin reaction?
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The tetrabutylammonium trifluoroacetate (TBATFA) catalyzed conversion of α,β-unsaturated carboxylic acids to the corresponding halides with N-halosuccinimides in dichloroethane is reported as the first example of a metal-free catalytic version of the title reaction. The methodology was further employed for a facile synthesis of piperine.
- Naskar, Dinabandhu,Chowdhury, Shantanu,Roy, Sujit
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p. 699 - 702
(2007/10/03)
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- STEREOSELECTIVE SYNTHESES OF SPICY COMPONENTS IN PEPPERS
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The syntheses of (E)-α,β-unsaturated amides were accomplished from chloroacetamides and alkyl halides via β-elimination of the pyrazinyl-sulfinyl group, and some of the products are spicy components of piperaceous plants.
- Ohta, Akihiro,Tonomura, Yoshiko,Sawaki, Junko,Naohito, Sato,Akiike, Hitomi,et al.
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p. 965 - 973
(2007/10/02)
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- HIGHLY STEREOSELECTIVE SYNTHESIS OF (2E,4E)-DIENAMIDES AND (2E,4E)-DIENOATES VIA A DOUBLE ELIMINATION REACTION
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Highly stereoselective synthesis of (2E,4E)-dienamides and (2E,4E)-dienoates was achieved through a double elimination reaction of β-acetoxy sulfones.
- Mandai, Tadakatsu,Moriyama, Tadashi,Tsujimoto, Koichiro,Kawada, Mikio,Otera, Junzo
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p. 603 - 606
(2007/10/02)
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- Substituent Effects on Carbon-13 NMR Chemical Shifts of Side-chain Carbons in 5-Aryl-2E,4E-pentadienoic Acid Derivatives
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The 13C NMR spectra of two series of 5-aryl-2E,4E-pentadienoic acid derivatives, viz. the methyl esters and piperidides have been determined.The chemical shifts of C-2 and C-4 show very good correlations with the Hammett ?+-constants for all the substituents investigated, except for the para-nitro group which is capable of excerting a strong -R effect.A possible explanation for this has been advanced.Hammett correlations between substituents and the chemical shifts of both C-3 and C-5 carbons using ?0 parameters are less satisfactory.A reverse chemical shift effect has been observed for these two centres.
- Banerji, Avijit,Ghosal, Tapasree,Acharyya, Aditi K.
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p. 546 - 549
(2007/10/02)
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- A Facile Synthesis of 3,4-Dienamides by the Reaction of Propargyl Alcohols with Cyclic Amide Acetals and Their Stereoselective Rearrangement to 2(E),4(Z)-Dienamides Promoted with Alumina. Total Synthesis of Isochavicine
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Thermal condensation of propargyl alcohols with acetals of 1-acetylpyrrolidine and 1-acetylpiperidine gave 3,4-dienamides in good yields.Alumina promoted the rearrangement of β-allenic amides to 2(E),4(Z)-dienamides stereoselectively.Its application to the synthesis of isochavicine of pepper components is described.Carbon-13 NMR data of these dienamides were obtained.
- Tsuboi, Sadao,Nooda, Yuji,Takeda, Akira
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p. 1204 - 1208
(2007/10/02)
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- New Approaches of Aldol-Type Reactions Demonstrated by Simple Syntheses of Piperine
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Piperine (3) is easily obtained by base-catalysed condensation of piperonal (1) and 1-crotonoyl-piperidine (2).
- Schulze, Andreas,Oediger, Hermann
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p. 1725 - 1727
(2007/10/02)
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- STEREOCONTROLLED SYNTHESIS OF CONJUGATED DIENAMIDES VIA YNAMINE-CLAISEN REARRANGEMENT WITH (ARYLTHIO)YNAMINE
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A new, versatile method for the stereocontrolled synthesis of conjugated (E,E)-dienamides is described wich relies upon the acid-catalyzed or thermal ynamine-Claisen rearrangement with readily accessible (arylthio)ynamines.
- Nakai, Takeshi,Setoi, Hiroyuki,Kageyama, Yasuhide
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p. 4097 - 4100
(2007/10/02)
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- Process for the preparation of piperonylidenecrotonic acid amides
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Process for the preparation of piperonylidenecrotonic acids amides of the formula STR1 in which R1 and R2 have the meaning given in the disclosure wherein piperonal is reacted with crotonic acid amides of the formula STR2 in the presence of hydroxides of the formula in which A+ represents a quaternary ammonium or phosphonium group or an alkali metal complex with neutral organic complex ligands, and polar aprotic or polar, sterically hindered protic organic solvents which are inert under the reaction conditions.
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- Process for the preparation of piperonylidenecrotonic acid amides
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Process for the preparation of piperonylidenecrotonic acid amides of the formula STR1 in which R1 and R2 have the meaning given in the disclosure wherein piperonal is reacted with crotonic acid amides of the formula STR2 in the presence of alkali metal hydroxides and dipolar aprotic diluents which are inert under the reaction conditions.
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