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1.
Eight N-substituted diketopiperazines (DKPs) were synthesized by solid-phase protocols. The introduction of iminodiacetic acid (Ida) and followed another α-amino acid residue as the precursor of DKP framework made the present synthesis to be very facile and efficient.  相似文献   

2.
《合成通讯》2013,43(23):4285-4291
Abstract

An efficient hydroxylation at the 5‐position of the C ring of camptothecins was accomplished with the complex of CuI and organic amines as catalyst in the presence of oxygen at room temperature in dimethyl formate (DMF). To be successfully hydroxylated, the insoluble camptothecin analogue was transformed to the corresponding 20 carbonates.  相似文献   

3.
Mercaptoalcohols are a rare class of natural products. Some optically active mercaptoalcohols have been used as catalysts in asymmetric reduction of prochiral Ketone1,2. In this letter, we report the synthesis of a new optically active (-mercaptoalcohols, (R)-1,1-diphenyl-2-mercapto-3-methyl-1-butanol 7, from L- valine.Our first attempt is showed in Scheme 1. According to literature's method L-valine was converted to (S)-2-Hydroxy-3-methylbutanoic acid 21,2. 2 was treated with MeOH/SOCl2…  相似文献   

4.
The reactions of cryptotanshinone and tanshinone llA with cadaverine and putrescine were investigated. Six new compounds, four with imidazole functional groups and two with oxazole groups, were obtained. The possible reaction mechanism was proposed.  相似文献   

5.
Becauseoftheimportanceofbenzothiazepinederivatives,whichexhibitversatilebiologicalactivities.thechemistryofbenzothiazepinehasarousedinterestforalongtime'-'.Inourpreviouspapers.wehavereportedthesynthesisandelucidationofthestereostructureoftwokindsofl,5-benzothiazepine-6-lactams'-'.InordertoelucidatetheinfluenceofthesizeofthesubstituentatC-2ontheconfigurationof0-lactammoietyandfurtherstudythestereochemistryofthecycloadditionreaction.wepreparedaseriesofnewfi-lactamderivativesofI.5-benzothiazepine…  相似文献   

6.
Three new α‐phenylcinnamic acid derivatives [4‐methoxy‐α‐phenylcinnamic acid, α‐(4‐methoxyphenyl)‐cinnamic acid, and 4,4′‐bismethoxy‐α‐phenylcinnamic acid] were synthesized, characterized, and selectively used for protecting the exocyclic amino function of purine nucleosides (2′‐deoxyadenosine and 2′‐deoxyguanosine) via active ester generation. The acids were first activated using p‐nitrophenol, and these activated esters were used subsequently for the selective protection of amino groups. The N‐protected derivatives of 2′‐deoxyguanosine and 2′‐deoxyadenosine have been found to be sufficiently stable toward acids, thus minimizing depurination under oligodeoxyribonucleotide synthesis protocol. The ease of syntheses of N‐protected purine nucleosides, their stability under an acidic environment, and mild deprotection conditions are the key advantages of the new protecting groups.  相似文献   

7.
Synthesis of New Fluorinated Podophyllotoxin Derivatives   总被引:4,自引:0,他引:4  
Five fluorinated podophyUotoxin derivatives were synthesized using dimethylamino-sulfurtrifluoride (DAST).  相似文献   

8.
Diels–Alder reactions of 3-vinylindoles were carried out with methyl acrylate and N-phenylmaleimide as dienophiles under microwave conditions to furnish unreported tetrahydrocarbazoles regio- and stereoselectively in good yields. Further dehydrogenation resulted in new substituted carbazoles.  相似文献   

9.
A general procedure for the synthesis of -iodostyrenes is proposed. Aromatic aldehyde and ketone hydrazones are converted into the corresponding -iodostyrenes by treatment with CHI3 in the presence of a catalytic amount of CuCl.  相似文献   

10.
Rajendran Suresh 《合成通讯》2013,43(14):1696-1703
A simple and efficient protocol for the construction of medicinally important substituted isoquinolines through intramolecular cyclization of β-hydroxyarylethanamides using acetic anhydride and phosphorous pentoxide in dioxane has been described. The chemo- and regioselectivities due to the influence of different catalysts were investigated and optimized for good to excellent yields. All the synthesized compounds have been characterized by NMR and mass spectral analyses.  相似文献   

11.
A series of arylsulfonamide and arylamide derivatives have been prepared from anisole in good yields.The structures of those compounds were confirmed by ^H-NMR and MS analysis.Their activities against platelet aggregation were tested in vitro by using the Born test on rabbits.  相似文献   

12.
Three-component reaction of aromatic aldehyde, 2-naphthalenamine, and 1,2-diphenylethanone in aqueous media catalyzed by triethylbenzylammonium chloride (TEBAC) at 90 °C gave 3-aryl-3-(naphthalen-2-ylamino)-1,2-diphenylpropan-1-one derivatives. The enol form of 1,2-diphenylethanone was tentatively proposed to participate in the formation of the products. Compared with previous methods, this three-component reaction has the advantages of green solvent, good yields, and operational simplicity.  相似文献   

13.
β-Cyclodextrin 1 was directly oxidized to the corresponding monoaldehyde 2 on their primary faces by cyclized 2-iodoxybenzoic acid(IBX) in DMSO, followed by the synthesis of β-cyclodextrin derivatives bearing Schiff-base group 3. A new chiral stationary phase(BCDS 6) was then prepared by immobilization of β-cyclodextrin derivative with α-Schiff base group onto the surface of sillica gel. A series of compounds with amino groups were readily separated using this CSE Methanol and acetonitrile were tested as the mobile phase while the influence of temperature and the addition of aqueous triethylammonium acetate buffer to the mobile phase was also innvestigated. Ferrocene ligand with Schiff-based groups have been separated satisfactorilly on BCDS column.  相似文献   

14.
(S)- and (R)-β-amino acid derivatives were synthesized by the asymmetric conjugate addition of ammonia and piperidazine to t-butyl (E)-2-[(R)- and (S)-p-tolylsulfinyl]cinnamates, respectively.  相似文献   

15.
A new type of Electrorheological materials made of an inclusive complex, which was synthesized by the means of molecular self-assembly, show a stronger electrorheological effec than that ofβ-cyclodextrin cross-linking polymer (β-CDP). Three approaches, named liquid-phase, solid-phase and liquid-solid-phase method, are respectively proposed to prepareβ-CDP-PAN, and show that both of the solid-phase and liquid-solid-phase methods are simple and convenient. The inclusion complex was characterized by the fluorescence spectrophotometer, IR and XRD confirming that the naphthalene ring of 1-(2-pyridlazo)-2-naphthol (PAN) was included in the glycopyranose unit ofβ-CDP.  相似文献   

16.
Application of the Mitsunobu reaction to various 3β-(equatorial)-hydroxy-4,4-dimethyl terpenic compounds provides the 2-ene-derivatives in good yields. A discussion about the mechanisms involved, and full details on the modified experimental protocol are given.  相似文献   

17.
A new two-step procedure has been developed for the synthesis of 2,2′: 6′,2″-terpyridine and 4′-methylsulfanyl-2,2′: 6′,2″-terpyridine in more than 70% yield on the basis of Potts’ condensation. Efficient methods have been proposed for purification of all condensation products.  相似文献   

18.
Abstract

A new method for the synthesis of α-amino-substituted benzyl-phosphonic or phosphinic acid (5) was descrided. By reaction of phosphoramides (1) with substituted benzaldehydes (2) and phosphite (3) in the presence of BF3, α-(N-phosphorylamino)-substituted benzylphosphonates or phosphinates (4) was obtained in moderate to good yield. This method distinguished itself by the simple manipulation and higher purity of the product resulted in both steps of the reaction sequences. Meanwhile, aminophosphonic esters are useful intermediated in the phosphorus peptide synthesis. The influence of variation in structure of 1, 2 and 3 on the yield of 5 was evaluated on the basis of sturcture-reactivity studies.  相似文献   

19.
以KF-Al2O3为催化剂合成了8种N-烷基化糖精衍生物,将超声波辐射应用于该反应使反应时间明显缩短。  相似文献   

20.
A New and Efficient Synthesis of Wedelolactone Derivatives   总被引:1,自引:0,他引:1  
A new and facile method based on an intermolecular cycloaddition was described for the synthesis of wedelolactone derivatives.  相似文献   

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