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1.
Terephthaldialdimine 1a reacted with alkenes to give 2,6-dialkylated products selectively in moderate to high isolated yields. In the case of terephthaldialdimine 1b having a substituent at site 2 in the phenyl ring, the alkylation takes place selectively at site 6 in the phenyl ring. In this alkylation, a meta-substituent affected the reactivity significantly because of the steric hindrance. 相似文献
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Alkylation of indoles has been achieved via Pd-catalyzed aliphatic C-H bond activation of tertiary amine coupling with indole followed by C-N bond cleavage and subsequent addition of indole. This method involves the migration of alkane chain from tertiary amine to indole. 相似文献
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The rhodium-catalyzed direct ortho-arylation reactions of phenylazoles using arylboron reagents such as tetraarylborates were examined. Ethyl chloroacetate and potassium fluoride were found to effectively act as a hydrogen acceptor and a promoter, respectively, to afford selective formation of the corresponding mono- or diarylated products with good yields. In addition, azobenzene as well as 2-phenylpyridine also underwent the direct arylation under similar conditions. 相似文献
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Hanjie MoWeiliang Bao 《Tetrahedron》2011,67(26):4793-4799
A metal-free coupling reaction between 1,3-diarylpropynes and alcohols/phenols/acids via propargylic sp3 C-H bonds activation and C-O bond formation reaction promoted by DDQ was realized. The reaction afforded series of propargyl ethers, propargyl esters and propargyl ketals. 相似文献
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Ji Min Lee 《Tetrahedron letters》2006,47(9):1375-1379
Synthesis of aryl lactones from ortho-alkyl substituted aromatic carboxylic acids is described on the basis of sp3 C-H bond activation using either palladium or platinum catalysts. Kinetic isotope studies reveal that the reaction takes place presumably by the chelation assistance of metal catalyst to the carboxylic group followed by the C-H bond activation. 相似文献
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A new and highly regioselective arylation of 2-arylbenzoxazoles based on C-H activation has been developed. The results represent the first examples of palladium-catalyzed direct ortho-arylation of 2-arylbenzoxazoles and also provide a facile route for the synthesis of complicated structures containing arylated benzoxazoles moieties. 相似文献
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Teruyuki Kondo Masatsugu Niimi Masato Nomura Kenji Wada Take-aki Mitsudo 《Tetrahedron letters》2007,48(16):2837-2839
A novel rhodium-catalyzed synthesis of substituted phenols by the ring-opening reaction of cyclobutenones with alkynes as well as electron-deficient alkenes has been developed. Both reactions involve C-C bond cleavage of cyclobutenones, and an (η4-vinylketene)rhodium complex rather than a rhodacyclopentenone is considered to be a key intermediate. 相似文献
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Alkenyl bromides were found to be useful reactants for the palladium-catalysed direct C-H activation/functionalisation reaction of heteroaromatics such as benzoxazole or benzothiazole. Moderate to good yields of coupling products were obtained using both α- and β-substituted alkenyl bromides or even the trisubstituted alkenyl bromide 2-bromo-3-methylbut-2-ene. This reaction is environmentally attractive as it provides only HX associated to the base as a by-product. 相似文献
12.
An efficient route to synthesize biologically interesting 8-aryl-1,2,3,4-tetrahydroisoquinoline has been developed. It involves the Pd-catalyzed direct arylation of 3,4-dihydroisoquinolones via C-H bond activation with aryl iodides to afford a variety of 8-arylated cross-coupling products, which are subsequently reduced to 8-aryl-1,2,3,4-tetrahydroisoquinolines in good to excellent yields. 相似文献
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A palladium-catalyzed ortho-selective C–H bond chlorination reaction for the preparation of 2-chloro aromatic ketones was described. Both electron-withdrawing and electron-donating groups on the aromatic rings are well tolerated under the optimized conditions. The 2-chloro aromatic ketones obtained by our method could be applied to synthesize the derivatives of 1H-indazole or benzo[d]isoxazole. 相似文献
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In the review paper, we attempt to point out the importance of the directing group in the transition metal-catalyzed C-H bond activation/transformations, especially in the site-selectivity and reactivity. The employment of the directing groups in the type of reaction can enable a chemist to straightforwardly approach the desired molecular skeletons. Thus, understanding the role of the directing groups in the C-H bond activation/transformations would benefit chemists to design better auxiliary groups and develop more efficient and practical synthetic methodologies. We believe that the synthetic strategy based on the utility of the directing group to assist in the transition metal-catalyzed C-H bond activation/transformations will keep playing as a mainstream role in the research field. 相似文献
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The C-S bond formation reactions of the transition metal sulfides with organic molecules are collected and reviewed to understand the reactivity of the sulfide ligands supported by the transition metals. As an example of the role of the sulfide, the C-H bond activation is focused and discussed. 相似文献
16.
Suparna Baksi Swati Dutta Michael G.B. Drew 《Journal of organometallic chemistry》2007,692(5):1025-1032
Reaction of 2-(2′-hydroxyphenylazo)phenol with [Rh(PPh3)3Cl] in refluxing benzene in presence of triethylamine afforded a red complex in which the ligand is coordinated to rhodium as a tridentate O,N,O-donor. However, similar reaction of [Rh(PPh3)3Cl] with 2-(2′-carboxyphenylazo)-4-methylphenol yielded two complexes, viz. a blue one and a green one. In both the complexes the ligand is coordinated as C,N,O-donor. However, in the blue complex orthometallation takes place from the ortho-carbon atom, which bears -COOH group via decarboxylation and in green one orthometallation occurs from the other ortho-carbon. Structures of all the three complexes were determined by X-ray crystallography. In all the three complexes rhodium is sharing the equatorial plane with the tridentate ligand and a chloride, and the two triphenylphosphines are axially disposed. All of the complexes show intense MLCT transitions in the visible region. Cyclic voltammetry on these complexes shows a Rh(III)-Rh(IV) oxidation on the positive side of SCE and a reduction of the coordinated azophenolate ligand on the negative side. 相似文献
17.
Kyoji Tsuchikama 《Journal of organometallic chemistry》2008,693(26):3939-3942
Cationic Ir complex ([Ir(cod)2]BF4 + BINAP) catalyzed the addition of ortho-C-H bonds in aryl ketones to alkynes, which gave alkenylated products in good to high yield. Styrene derivatives were good substrates, and the enantioselective addition to norbornene was also described. 相似文献
18.
The formation of carbon-nitrogen bonds by reaction between a nitrogen atom and an unactivated carbon-hydrogen bond is a highly atom-economical process that attracted the attention of the chemists in the last two decades. The widely useful amination and hydroamination reactions, which furnish acyclic or cyclic products, give access to various nitrogen-containing basic and fine chemicals. This review highlights recent progress in the development of palladium-catalyzed reactions that occur by direct functionalization of simple carbon-hydrogen bonds to give heterocyclic products. Pd(0)- and Pd(II)-catalyzed reactions are described separately, emphasizing the different behavior of the metal in these two oxidation states. 相似文献
19.
三价铑在氧化条件下催化N-烷基苯甲酰胺与醌反应生成芳基醌.在氧化还原中性条件下,经过偶联和内酯化反应可以得到2-羟基-6H-苯并[c]吡喃-6-酮. 相似文献
20.
High costs and low catalytic efficiency of metalloporphyrins, which are an analogue of cytochrome P450 enzyme, are the bot-tlenecks in the industrialization of biomimetic hydrocarbon oxidation reactions. The basic principle and research technique of physical organic chemistry were applied to the process of biomimetic oxidation of hydrocarbon catalyzed by metalloporphyrins. This biomimetic technology could be adapted to bulk chemicals production by developing the new methods for efficient scale-up synthesis of metalloporphyrins, new pathways for molecular oxygen activation on an industrial scale and new approaches to elevate the catalytic efficiency of metalloporphyrins. This review mainly focuses on research carried out in our group. 相似文献