首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
《Tetrahedron letters》1988,29(2):225-226
Two-stage Ullmann and phenol coupling were effected in a singleoperation on methyl 5-bromo-1,2-dihydroxy-6,8-dimethoxynaphthalene-3-acetate to give dimethyl 5,8-dihydroxy-1,3,10,12-tetramethoxy-4,9-perylenequinone-6,7-diacetatewith ferric chloride as oxidant.  相似文献   

2.
3.
Sun PP  Chang MY  Chiang MY  Chang NC 《Organic letters》2003,5(10):1761-1763
[reaction: see text] Base-induced coupling/cyclization reactions of alpha-sulfonylacetamide with various ethyl (Z)-2-bromo-2-propenoates have been carried out. The polysubstituted pyroglutamate carbon skeleton, with three contiguous asymmetric centers, was built up in one step. A ring-closure mechanism is proposed for the reactions.  相似文献   

4.
A facile method for the synthesis of new pyrazoloisoindolones via a Suzuki cross-coupling reaction using a pyrazolylboronic ester is described.  相似文献   

5.
Summary A one-pot synthesis of highly functionalized ketenimines by reaction of alkyl isocyanides with dialkyl acetylenedicarboxylates in presence of 1,3-diphenylpropan-1,3-dione is reported.
Ein einfacher Weg zu hochfunktionalisierten Keteniminen
Zusammenfassung Es wird eine Eintopfsynthese hochfunktionalisierter Ketenimine durch Reaktion von Isocyaniden mit Dialkylacetylendicarboxylaten in Gegenwart von 1,3-Diphenylpropan-1,2-dion beschrieben.
  相似文献   

6.
2-Substituted tetrahydro- and cyclopentathiophenes 2 were produced in high yields by treatment of the semi-cyclic trisubstituted 1,4-diketones 1 such as 2-phenacylcyclohexan-1-one, 2-acetonylcyclohexan-1-one, and 2-phenacylcyclopentan-1-one, with Lawesson's reagent.  相似文献   

7.
A series of difunctionalized monosubstituted octasilsesquioxanes have been synthesized that bear ester, amino acid, alcohol, haloalkyl, or azido functional groups. These units are suitable nanobuilding blocks for the preparation of new organic-inorganic hybrid materials.  相似文献   

8.
The synthesis of monodisperse dendrimers triggers a great challenge to the synthetic chemistry. Here, we reported a facile convergent approach to the synthesis of the first generation, six-directional ether-bond polyols with better controlled structures and ease of purification.  相似文献   

9.
2-Quinolones are prepared from o-aminophenylketones by N-acylation with phosphonoalkanoylchlorides, followed by an intramolecular Horner-Wadsworth-Emmons olefination. The transformation proceeds under mild conditions, is generally applicable, gives good yields and can be performed either in two steps or as a one-pot reaction.  相似文献   

10.
Access to vinyloxiranes using aldehydes and allylic bromides in the presence of 1-5 mol% tetrahydrothiophene is reported. Both aliphatic and aromatic aldehydes work well in this reaction and the catalyst loading could be reduced as low as 0.5 mol%.  相似文献   

11.
Uracil nucleosides and nucleotides undergo a palladium catalyzed coupling reaction with styrenes to yield the respective 5-substituted derivatives.  相似文献   

12.
An efficient methodology is reported for the regioselective C-6 arylation of protected uracil via the palladium catalyzed CH functionalization of 1-(4-methoxybenzyl)-3-methylpyrimidine-2,4(1H,3H)-dione with (hetero)aryl halides and boronic acids. Utilization of the Pd(OAc)2/Xantphos catalytic system with a stoichiometric amount of CuI and DBU as the base was vital for the success of this protocol. The methodology is facile and compatible with aryl bromides, iodides and boronic acids and hence affords broad substrate scope and diversity.  相似文献   

13.
Various cyclopentenones are obtained in fair to high yields when ethylenic acyl bromides are condensed with cyclohexene at low temperature. With less reactive reagents, condensation occurs at 0 °C, leading to β-chloro-ketones. A muscone precursor is obtained in two steps with excellent yields.  相似文献   

14.
Using achiral coordinatively unsaturated metal complex building-blocks, the two step synthesis of a bimetallic complex containing independent [Ru(II)dppz] units tethered together by a linking 4,4'dipyridyl-1,5-pentane ligand is reported. Photophysical studies on this prototype system indicate that the characteristic luminescence of the [Ru(II)dppz] moieties is perturbed by self-quenching processes. Preliminary binding studies on the complex with natural and synthetic duplex DNA is reported. Luminescence and calorimetric titrations reveal that the complex does not show enhanced binding affinity with respect to analogous monometallic complexes. This result is interpreted by a consideration of the length and rigidity of the linker employed in the complex.  相似文献   

15.
16.
A three-step preparation of a polymer-supported IBX reagent from poly(p-methylstyrene) is reported. This reagent has been used successfully for the efficient oxidation of a series of alcohols to the corresponding aldehydes.  相似文献   

17.
Grignard reagents react with 7-oxabicyclo[2.2.1]hept-5-ene-2,3-dicarboxylic anhydride and produce in high yields the corresponding substituted bicyclo-γ-butanolides. These lactones produce the title compounds by retro Diels-Alder reaction during distillation.  相似文献   

18.
The determination of the actual electrode surface temperature is important for all electrochemical methods using in situ heating of electrodes. Existing methods of temperature measurement of a heated thin-wire electrode are of restricted use and critically discussed in the introduction. The use of the electrode wire itself as a resistive thermometer is improved in the present method. With the new thermoelectrochemical method temperature pulse voltammetry, the reliability of different thermometric methods can be compared. In this way, it is ensured to have correct temperature measurements at wire microelectrodes in all common solvents available.  相似文献   

19.
A facile synthesis of a 5,7,5-fused ring system that is present in thapsigargins belonging to a novel family of sesquiterpene lactones, guainanolides, using domino enyne-RCM is reported here.  相似文献   

20.
2-Fluoropyrroles were synthesised via 1,3-dipolar cycloaddition of iminiodifluoromethanides derived from corresponding imines and difluorocarbene to dimethyl acetylenedicarboxylate.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号