共查询到20条相似文献,搜索用时 0 毫秒
1.
Albert Kascheres Heloisa C. Schumacher Reinaldo A. F. Rodrigues 《Journal of heterocyclic chemistry》1997,34(3):757-759
New pyrrolizidine derivatives 6 and 7 were prepared from the 1, 5-dihydro-2H-pyrrol-2-one 3a via an acidic intramolecular aldol condensation in 16% and 42% yields, respectively. Compound 6 was obtained by dehydration of 7 with p-toluenessulfonic acid in 67% yield. 相似文献
2.
A series of fullerene substituted phenylalanine derivatives have been prepared by the condensation of 1,2-(4'-oxocyclohexano)fullerene with ester or Boc protected (4-amino)phenylalanine, H(2)NC(6)H(4)CH(2)CH(COR(1))(NHCOR(2))(where R(1) = OMe, R(2) = Me; R(1) = OH, R(2) = Me, O(t)Bu). Conversion of the imine to the corresponding amine is achieved by di-acid catalyzed hydroboration. Reaction of the N-Ac amino ester with BBr(3) led to the formation of the parent amino acid, while the Boc-protected derivative readily undergoes coupling with NH(2)-Gly-OEt. The reduction of the imine is not accompanied by hydroboration of the fullerene cage. 相似文献
3.
Kunio Atsumi Kiyoaki Katano Ken Nishihata Fumio Kai Eiichi Akita Taro Niida 《Tetrahedron letters》1982,23(29):2977-2980
Treatment of 7β-(2,2,3-trihaloalkylideneamino) cephalosporins with excess methanol in the presence of acid scavenger gave 7β-(2-haloalk-2-enylideneamino)-7α-methoxycephalosporins. 相似文献
4.
We have developed a new synthetic route to phomoidride B, which could also be applied to the synthesis of phomoidride B derivatives using Pd-catalyzed coupling reaction of a thiolester with an organozinc reagent. In addition, direct construction of the maleic anhydride moiety has been achieved by a Pd-catalyzed carbonylation reaction. 相似文献
5.
A new synthetic route for the synthesis of the nordasycarpidone derivative 11 which has hexahydro‐1,5‐methanoazocino[4,3‐b]indol skeleton, is described. Construction of the tetracyclic structure was achieved by catalytic reduction and cyclization reaction of the nitrile derivative. Also many new tetrahydrocarbazole derivatives ( 4, 5, 6, 7, 8, 9 ) and a dasycarpidol derivative ( 10 ) were synthesized. 相似文献
6.
A general synthetic route to indenofluorene derivatives as new organic semiconductors 总被引:1,自引:0,他引:1
A series of 2,6-disubstituted indenofluorene derivatives were obtained in high purity via a general route involving the Suzuki coupling reaction. The potential of these conjugated indenofluorenes as new organic semiconductors was demonstrated by the light-emitting diode reaching a high luminance of 1400 Cd/m(2) below 10 V. [structure: see text] 相似文献
7.
Pierre Reynaud Youssef El Hamad Catherine Davrinche Emmanuel Nguyen-Tri-Xuong Gilles Tran Pierre Rinjard 《Journal of heterocyclic chemistry》1992,29(4):991-993
2-Substituted 1,3,4-oxadiazoles have been examined as possible prodrugs of antidepressant hydrazides. A new method of synthesis of this heterocycle from thionoester and five new oxadiazoles substituted at the 2-position by a 4-pyridyl or 4-aminophenyl group and at the 5-position by a phenyl group are described. 相似文献
8.
A stereo-divergent synthetic strategy based on diastereoselective vinylation of an α-amino aldehyde, ring-closing metathesis reaction and diastereoselective dihydroxylation reaction as key steps has been developed for the synthesis of three aminocyclopentitol derivatives of chemical and biological relevance. 相似文献
9.
A novel approach to the titled ring system starting from conveniently available chalcones 1 is proposed. It involves a catalysed exchange of hydrogen cyanide between acetone cyanohydrin and 1 . The resulting γ-ketonitriles 2 give the expected 4,6-diarylpyridazinones 4 and 5 via hydrolysis and cyclisation by hydrazine. The action of phosphorus oxychloride on 5 followed by that of amines provides aminopyridazines 7 . 相似文献
10.
Fawi M. Abd El Latif 《Heteroatom Chemistry》1995,6(6):575-578
New pyrazolo-[3,4-b]-[1,5]-benzoazepinone derivatives are reported. One pot reactions of 5-chloro-4-carboxy-1-phenyl (3-substituted) pyrazole derivatives with o-thioaminophenol, o-phenylenediamine, and o-aminophenol derivatives were realized. The influences of the polarizability of the heteroatoms on the reaction rates and chemical yields are discussed. © John Wiley & Sons, Inc. 相似文献
11.
Schiff's bases derived from ketones and t-butylamine ( 1 ) reacted with methyl methoxymethylenemalonate to give 2-hydroxy-3-pyridinecarboxylates. Similarly, treatment of 1 with ethoxymethylenemalononitrile gave 2-amino-3-pyridinecarbonitriles. Compounds 1 on reaction with ethyl 2-cyano-3-ethoxypropenoate afforded 2-amino-3-pyridinecarboxylates. 相似文献
12.
Cross-metathesis between an activated olefin and an ethereal derivative of homoallylic alcohols leads to products that are subject to facile elimination resulting in α,β,γ,δ-unsaturated esters, ketones, acids, and aldehydes in high yields. 相似文献
13.
[reaction: see text]Reaction of indole amides 5 with tributylstannane gave spiroindolenines 9 which are readily converted into spiropyrrolidinyloxindoles. This tricyclic system is found in a number of interesting natural products. 相似文献
14.
Shigeki Oishi 《Tetrahedron letters》2008,49(45):6426-6428
Reaction of titanium cyclobutylidene complexes, prepared by the desulfurizative titanation of 1,1-bis(phenylthio)cyclobutanes with Cp2Ti[P(OEt)3]2, with alkynes gave 1-(alk-1-enyl)cyclobutenes. 相似文献
15.
Dralle K Jaffa NL le Roex T Moss JR Travis S Watermeyer ND Sivaramakrishna A 《Chemical communications (Cambridge, England)》2005,(30):3865-3866
Reaction of the bis-alkenyl complex cis-[Pt(PPh3)2(CH2CH2CH=CH2)2] with Grubbs 1st generation catalyst gives, in high yield, the metallacycloalkene cis-[Pt(PPh3)2(CH2CH2CH=CHCH2CH2)], which can be hydrogenated to the metallacycloalkane cis-[Pt(PPh3)2(CH2)6]. 相似文献
16.
17.
18.
M. Bakavoli M. Rahimizadeh A. R. Ebrahimi A. Taghizadeh A. Davoodnia M. Nikpour 《Journal of heterocyclic chemistry》2008,45(5):1465-1468
Cyclocondensation of orthophenylendiamines with 3‐bromopropionic acid in PPA afforded 2‐vinylbenzimidazoles which were subsequently converted to their corresponding 2‐(1,2‐dibromoethyl)‐1H‐benzimidazoles on treatment with bromine. Reaction of these compounds with aryl nitriles or aryl isocyanates in basic chloroform yielded 1‐arylpyrimido[1,6‐a]benzimidazoles and 2‐arylpyrimido[1,6‐a]‐benzimidazol‐3‐ones respectively. 相似文献
19.
B. Bachowska 《Chemistry of Heterocyclic Compounds》2011,47(3):332-335
A smooth synthesis of benzo[c][1,5]naphthyridine-6-carbonitrile and benzo[h][1,6]naphthyridine-5-carbonitrile, starting from
benzonaphthyridine N-oxides, is achieved by treatment with trimethylsilane carbonitrile (Me3SiCN) in CH2Cl2 at 0–5 °C. The
resulting nitriles are then hydrolyzed to the corresponding acids by boiling in aqueous alkali. 相似文献
20.
K. Soga S. Hosoda S. Ikeda 《Journal of polymer science. Part A, Polymer chemistry》1979,17(2):517-529
A detailed study has been carried out on the new synthetic reaction of poly(p-xylylene carbonate) from potassium carbonate and p-xylylene dibromide by using a variety of crown ethers as a catalyst, which was recently found by the present authors. Crown ethers having 18-member ring showed the best catalytic property of the various crown ethers, and the reaction was conducted in various solvents at 50–160°C by using 18-crown-6-ether. Both the polymer yield and the molecular weight of the polymer increased in proportion to the amount of potassium carbonate, and they increased rapidly and reached constant values with increasing the concentration of 18-crown-6-ether. They also depended significantly upon the reaction temperature as well as the solvent used. A maximum yield with the highest molecular weight was obtained from the reaction at 100–120°C in diglyme solvent. The spectroscopic analysis of the polymer indicated that all the end groups of the resulting polymer had the structure of benzyl bromide. From these results, a plausible mechanism was proposed for the reaction. Similar reactions were also conducted by using several aliphatic dibromides, Br? (CH2)x? Br, in place of p-xylylene dibromide. The products were strongly dependent of the value of x: polycarbonate was obtained from dibromides with ≧4, and cyclic carbonates from dibromides with ≦3. 相似文献