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1.
Rhodium‐Catalyzed [3+2+2] and [2+2+2] Cycloadditions of Two Alkynes with Cyclopropylideneacetamides 下载免费PDF全文
Tomoka Yoshida Yuki Tajima Masayuki Kobayashi Koji Masutomi Prof. Dr. Keiichi Noguchi Prof. Dr. Ken Tanaka 《Angewandte Chemie (International ed. in English)》2015,54(28):8241-8244
It has been established that a cationic rhodium(I)/H8‐binap complex catalyzes the [3+2+2] cycloaddition of 1,6‐diynes with cyclopropylideneacetamides to produce cycloheptadiene derivatives through cleavage of cyclopropane rings. In contrast, a cationic rhodium(I)/(S)‐binap complex catalyzes the enantioselective [2+2+2] cycloaddition of terminal alkynes, acetylenedicarboxylates, and cyclopropylideneacetamides to produce spiro‐cyclohexadiene derivatives which retain the cyclopropane rings. 相似文献
2.
Bruce H. Lipshutz Daniel Pollart Joseph Monforte Hiyoshizo Kotsuki 《Tetrahedron letters》1985,26(6):705-708
PdCl2(CH3CN)2 catalyzes the hydrolysis of dioxolane acetals and ketals in moist CH3CN, while in acetoze, efficient and more reproducible exchange reactions take place. 相似文献
3.
The kinetics and mechanism of the action of tetra- and octanuclear ruthenium catalysts for water oxidation with Ce(IV) compounds in “artificial photosynthesis” have been studied. These catalysts are formed from a complex K4[Ru2(SO4)2(μ-SO4)2(μ-O)2] · 2H2O in an acidic medium via its self-organization. A tetranuclear adamantane-like cluster Ru4O6 is obtained during the dimerization of a binuclear complex and catalyzes the four-electron water oxidation to an oxygen molecule. An octanuclear cluster Ru8O12 is formed during the tetramerization of a binuclear complex and catalyzes the eight-electron water oxidation to an oxozone molecule O4, which readily splits to two oxygen molecules. 相似文献
4.
Bis(triphenylphosphine)palladium(II) dichloride (PdCl2(PPh3)2) catalyzes regioselective addition of benzeneselenol to terminal alkynes and the subsequent double-bond isomerization to afford the corresponding internal alkenyl selenides in good yields. 相似文献
5.
RuCl2(PPh3)3 catalyzes oxidation of alcohols to carbonyi compounds by iodosylbenzene and that of aldehydes to carboxylic acids. Catalyzed oxidation of primary alcohols with phenyliodosodiacetate affords aldehydes. 相似文献
6.
Macrocyclic Ni(II) complex, 1, catalyzes efficiently the chemoselective transfer reduction of carbonyl compounds in presence of propan-2-ol / KOH or HCO2H / HCO2NH4 as hydrogen donors to produce the corresponding alcohols in high yield. 相似文献
7.
Alireza Hasaninejad Khodabakhsh Niknam Abdolkarim Zare Ehsan Farsimadan Mohsen Shekouhy 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1):147-155
Silphox [POCl3-n(SiO2)n] efficiently catalyzes the condensation of benzene-1,2-diamine with mono and dicarboxylic acids under microwave irradiation to afford benzimidazole derivatives in high yields and short reaction times. 相似文献
8.
MgBr2 · OEt2 efficiently catalyzes the O- and N-tert-butoxycarbonylation of functionalized phenols and amines. The presented procedure is operationally simple and done under solvent-free conditions. 相似文献
9.
Valente Gómez-Benítez 《Tetrahedron letters》2006,47(29):5059-5062
[NiCl{C6H3-2,6-(OPPh2)2}] efficiently catalyzes the thiolation of iodobenzene with a broad scope of disulfides in the presence of zinc, the coupled products are obtained in excellent and in many cases nearly quantitative yields. 相似文献
10.
Mieko Arisawa 《Tetrahedron letters》2005,46(36):6097-6099
RhH(PPh3)4 catalyzes reduction of disulfides to thiols by hydrogen and RhH(PPh3)4/1,4-bis(diphenylphosphino)butane (dppb) catalyzes oxidation of thiols to disulfides by oxygen. 相似文献
11.
Suribabu Jammi 《Tetrahedron letters》2008,49(9):1484-1487
NiCl2·6H2O efficiently catalyzes the C-S bond formation by the cross-coupling of aryl iodides with thiols in tetrabutylammonium bromide (TBAB) in excellent yield. The reaction functions in air and the NiLn-TBAB can be recovered and recycled without the loss of activity. 相似文献
12.
Co(acac)2·2H2O efficiently catalyzes SnCl2-mediated Barbier coupling in water between carbonyls, including aromatic, aliphatic and α,β-unsaturated aldehydes, ketones, sugars and allyl bromide to afford the corresponding homoallylic alcohols in high yields. The catalyst was reused for several cycles with consistent activity. 相似文献
13.
MgC2O4/SiO2 catalyzes the efficient Knoevenagel condensation of aldehydes with active methylene compounds in solvent-free conditions under microwave irradiation to give alkenes derivatives in excellent yields. MgC2O4/SiO2 can be reusable for Knoevenagel condensation. However, ketones have been found to be unsatisfactory in the reaction under the same conditions. 相似文献
14.
M. M. Khodaei A. R. Khosropour M. Kookhazadeh 《Russian Journal of Organic Chemistry》2005,41(10):1445-1448
Cerium(III) chloride heptahydrate CeCl3 · H2O catalyzes enamination of β-dicarbonyl compounds with primary amines in aqueous medium at room temperature to afford the corresponding β-enamino ketones with high chemoselectivity. 相似文献
15.
Fe2(SO4)3 · xH2O catalyzes the Ferrier reaction of per‐O‐acetylated/benzylated glycals with alcohols to give 2,3‐unsaturated α‐glycosides in a few minutes under microwave irradiation. 相似文献
16.
Muthian Shanmugasundaram 《Tetrahedron letters》2007,48(43):7698-7701
The [Ir(COD)Cl]2/dppe system effectively catalyzes the solid-phase [2+2+2] cycloaddition of resin-bound dipropargylamine with alkynes under microwave conditions. The reaction results in high purity of isoindoline derivatives with moderate yields. 相似文献
17.
[RuCl2(CO)3]2 catalyzes intermolecular cyclopropanation of various alkenes with propargylic acetates to give vinylcycloropanes in good yields. The key intermediate of this reaction is a vinylcarbene complex generated by nucleophilic attack of the carbonyl oxygen of the acetate to an internal carbon of alkyne activated by the ruthenium complex. 相似文献
18.
Kazuhide Tani Kazuya Ueda Kenji Arimitsu Tsuneaki Yamagata Yasutaka Kataoka 《Journal of organometallic chemistry》1998,560(1-2)
Cationic Rh(I) complex [Rh(binap)(MeOH)2]ClO4 catalyzes reductive dimerization of dialkyl acetylenedicarboxylates 1 to give 1,2,3,4-tetrakis(alkoxycarbonyl)-1,3-butadienes 2 in methanol selectively. 相似文献
19.
《Journal of organometallic chemistry》1989,364(3):C33-C36
Electrochemically reduced Ni(bipy)3(BF4)2 catalyzes the reaction of carbon dioxide with disubstituted alkynes to yield mono- and di-carboxylated derivatives. The reaction is performed under mild conditions in an undivided cell fitted with a sacrificial magnesium anode. 相似文献
20.
This paper focuses on the group of metalloproteins/metalloenzymes in the acetyl-coenzyme A synthesis pathway of anaerobic
microbes called Wood-Ljungdahl pathway, including formate dehydrogenase (FDH), corrinoid iron sulfur protein (CoFeSP), acetyl-CoA
synthase (ACS) and CO dehydrogenase (CODH). FDH, a key metalloenzyme involved in the conversion of carbon dioxide to methyltetrahydrofolate,
catalyzes the reversible oxidation of formate to carbon dioxide. CoFeSP, as a methyl group transformer, accepts the methyl
group from CH3-H4 folate and then transfers it to ACS. CODH reversibly catalyzes the reduction of CO2 to CO and ACS functions for acetyl-coenzyme A synthesis through condensation of the methyl group, CO and coenzyme A, to finish
the whole pathway. This paper introduces the structure, function and reaction mechanisms of these enzymes. 相似文献