共查询到20条相似文献,搜索用时 11 毫秒
1.
Arno Behr Franz Naendrup Dietmar Obst 《Advanced Synthesis \u0026amp; Catalysis》2002,344(10):1142-1145
Different Pt(IV), Pt(II) and Pt(0) catalysts were screened for the hydrosilylation of fatty acid esters containing terminal as well as internal double bonds. The reaction of terminally unsaturated fatty acid esters proceeded smoothly with short reaction times for nearly all examined catalysts, whereas Pt(IV) species and Pt(II) or Pt(0) species with labile ligands were sufficiently active in the reaction of internally unsaturated compounds. For methyl linoleate, a conjugation of the two internal double bonds before the hydrosilylation was observed. The reaction was carried out in substance as well as in solvent systems permitting a catalyst recycling and reuse. In these systems, however, hydrogenation and double bond isomerisation were found as side reactions. 相似文献
2.
Benito Alcaide Pedro Almendros Israel Fernndez Teresa Martínez del Campo Teresa Naranjo 《Advanced Synthesis \u0026amp; Catalysis》2013,355(13):2681-2685
α‐Allenols were catalytically transformed into dihydrofurans in the presence of platinum dichloride. Notably, using platinum dichloride along with silver triflate as the catalytic system, α,β‐unsaturated ketones were obtained. Therefore, the role of the silver salt may not just consist in the activation of the platinum precatalyst.
3.
Daniel Pflsterer Praphasiri Dolbundalchok Shahid Rafique Matthias Rudolph Frank Rominger A. Stephen K. Hashmi 《Advanced Synthesis \u0026amp; Catalysis》2013,355(7):1383-1393
Aniline derivatives with allene side tethers were tested as substrates for a gold‐catalyzed 7‐exo‐trig hydroamination reaction. The nucleophilicity of the aniline derivatives plays an important role for the outcome of the reaction. While electron‐deficient protecting groups at the nitrogen led to competing pathways like hydroarylation or an allene to diene isomerization, clean formation of the desired benzoxazepines was obtained with unprotected aniline derivatives. 相似文献
4.
In this communication, we report the synthesis of a new chiral spiro‐bisoxazoline ligand, i.e., β‐naphthylmethyl‐substituted spiro‐BOX [(Ra,S,S)‐ L7 ] and have successfully applied it to the palladium‐catalyzed enantioselective cyclization reaction of simple allenes with o‐aminoiodobenzenes, affording highly optically active 3‐alkylideneindolines in good yields with excellent enantiomeric excesses. 相似文献
5.
Takeshi Hata Satoshi Iwata Shumpei Seto Hirokazu Urabe 《Advanced Synthesis \u0026amp; Catalysis》2012,354(10):1885-1889
Treatment of 2‐alken‐4‐ynoates with methyl‐ or aryl‐Grignard reagents and iron(II) chloride (10 mol%) afforded 5‐methyl‐ or 5‐aryl‐3,4‐alkadienoates in good yields as a single isomer after aqueous work‐up. Likewise, (2‐alken‐4‐ynoyl)oxazolidinones afforded (5‐methyl‐3,4‐alkadienoyl)oxazolidinones. The aldol‐type reaction with acetone was also possible in place of the hydrolytic work‐up. 相似文献
6.
Silaboration of 1,3‐cyclohexadiene in the presence of Pt(acac)2, DIBALH, and a phosphoramidite prepared from (S)‐1,1′‐bi‐2‐naphthol and diisopropylamine led to (1R,4S)‐1‐(dimethylphenylsilyl)‐4‐(4,4,5,5‐tetramethyl‐1,3,2‐dioxaborolan‐2‐yl)‐2‐cyclohexene with 70% ee. Chiral catalysts based on Ni gave no or essentially racemic product, whereas complexes containing Pd were inactive. 相似文献
7.
Kohsuke Aikawa Masafumi Kojima Koichi Mikami 《Advanced Synthesis \u0026amp; Catalysis》2010,352(18):3131-3135
A synergistic effect is observed for the combination of a neutral dinuclear gold complex with a chiral silver phosphate in the intramolecular hyroalkoxylation of allenes to give furan derivatives in high yields and enantioselectivities. The monocationic dinuclear gold complex affords higher catalytic activity and enantioselectivity than the neutral or dicationic digold complexes. The synergistic effect is thus highly promising to provide a guiding principle in designing an efficient chiral environment for creating an asymmetric catalyst. 相似文献
8.
Xavier Moreau Jean‐Philippe Goddard Matthieu Bernard Gilles Lemire Juan Manuel Lpez‐Romero Emily Mainetti Nicolas Marion Virginie Mouris Serge Thorimbert Louis Fensterbank Max Malacria 《Advanced Synthesis \u0026amp; Catalysis》2008,350(1):43-48
Polycyclic derivatives incorporating a cyclopropyl group have been efficiently synthesized from propargyl acetates using platinum(II), gold(I) and gold(III) catalysis. These reactions which are also viable for the preparation of medium‐sized rings, proceed with a complete diastereocontrol and can also be run in neat conditions. 相似文献
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10.
Jinqiang Kuang Hongwen Luo Shengming Ma 《Advanced Synthesis \u0026amp; Catalysis》2012,354(5):933-944
An efficient one‐step synthesis of functionalized allenes from readily available functionalized terminal alkynes and aldehydes by applying the effect of a dialkylamine has been developed. The protocol is catalyzed by copper(I) iodide and the dialkylamine is believed to play a very important role in the transformation. 相似文献
11.
Samer Saleh Elie Fayad Michle Azouri Jean‐Cyrille Hierso Jacques Andrieu Michel Picquet 《Advanced Synthesis \u0026amp; Catalysis》2009,351(10):1621-1628
The straightforward synthesis of a new donor‐stabilized phosphenium ligand 3d by addition of bromodifurylphosphine to 1,3‐dimethylimidazolium‐2‐carboxylate 1 is described. The obtained ligand exhibits a very strong π‐acceptor character, comparable to that of triphenyl phosphite [P(OPh)3] or of tris‐halogenophosphines, with a νCO(A1) at 2087 cm−1 for its nickel tricarbonyl complex. This ligand, as well as the related 3a which was obtained from chlorodiphenylphosphine, were tested in palladium‐catalyzed aryl alkynylation and in the platinum‐catalyzed selective hydrogenation of chloronitrobenzenes, both in an ionic liquid phase. In C C bond cross‐coupling we observed that the increase of the π‐acceptor character in ligand 3d , due to the introduction of an additional electron‐withdrawing group, provides a very efficient catalyst in the alkynylation reaction of aryl bromides with phenylacetylene, including the deactivated 4‐bromoanisole or the sterically hindered 2‐bromonaphthalene. The catalytic activity decreases with recycling due to the sensitiveness of ligands to protonation in the ionic phase. Conversely, a multiple recycling of the metal/ligand system in non‐acidic media was achieved from platinum‐catalyzed hydrogenation of m‐chloronitrobenzene. The catalytic results obtained by employing the complex of platinum(II) chloride with 3a [trans‐PtCl2( 3a )2] in comparison with the non‐ionic related trans‐tris(triphenylphosphine)platinum dichloride [trans‐PtCl2(PPh3)2] complex clearly indicate that the simultaneous existence of a strong π‐acceptor character and a positive charge within the ligand 3a significantly increases the life‐time of the platinum catalyst. The selectivity of the reaction is also improved by decreasing the undesirable formation of dehalogenation products. This cationic platinum complex trans‐PtCl2( 3a )2 is the first example of a highly selective catalyst for hydrogenation of chloronitroarenes immobilized in an ionic liquid phase. The system was recycled six times without noticeable metal leaching in the organic phase, and no loss of activity. 相似文献
12.
Xin Huang Xinpeng Jiang Chunling Fu Shengming Ma 《Advanced Synthesis \u0026amp; Catalysis》2013,355(16):3295-3303
A highly regioselective synthesis of 15–20‐membered macrocycles via Pd(0)‐catalyzed coupling cyclization of allenes bearing a carbon or nitrogen nucleophilic functionality and organic iodides is reported. After oxidative addition and carbopalladation, anti‐π‐allyl palladium intermediates were formed, which was followed by the exclusive intramolecular nucleophilic attack at the terminal carbon atom of the allene moiety to afford products with yields ranging from 44–92% and E/Z ratios of up to 97/3.
13.
Valrian Gob Maxime Dousset Pascal Retailleau Vincent Gandon Xavier Guinchard 《Advanced Synthesis \u0026amp; Catalysis》2016,358(24):3960-3965
N‐Allyltetrahydro‐β‐carbolines bearing a pendant allene undergo unprecedented gold(I)‐catalyzed cyclizations proceeding with an allyl migration from the nitrogen to the allene moiety. The initial product of the gold‐catalyzed cyclization evolves either via isomerization or Cope rearrangement, leading to different scaffolds. Density function theory (DFT) calculations established that the allyl migration occurs in an asynchronous suprafacial manner.
14.
Copper‐catalyzed highly selective borylcuprations of allenes with bis(pinacolato)diboron produce two different types of alkenylboranes by applying a ligand effect. In the presence of tris(para‐methoxyphenyl)phosphine [P(C6H4OMe‐p)3], the reaction of aryl‐1,2‐dienes affords 2‐alken‐2‐yl boronates as the only product with exclusive Z‐geometry; the regioselectivity is switched to afford the 1‐alken‐2‐yl boronates as the major products when the bidentate phosphine 2,2′‐bis(diphenylphosphino)biphenyl is used as the ligand. 相似文献
15.
Nobuhiro Ito Tsutomu Watahiki Tsuneaki Maesawa Tomohiro Maegawa Hironao Sajiki 《Advanced Synthesis \u0026amp; Catalysis》2006,348(9):1025-1028
We have found a synergistic effect in the H‐D exchange reaction of alkyl‐substituted aromatic compounds using the Pd/C‐Pt/C‐D2O‐H2 system. This system would lead to fully H‐D exchange results even on the sterically hindered sites which were only low‐deuterium incorporated by Pd/C or Pt/C independently. Since the reaction was general for a variety of aromatic compounds, it could be applied to the deuteration of dianiline derivatives as raw materials for polyimides. 相似文献
16.
Zhenhua Gu Youqian Deng Wei Shu Shengming Ma 《Advanced Synthesis \u0026amp; Catalysis》2007,349(10):1653-1656
An efficient protocol for the highly regio‐ and stereoselective synthesis of 4‐(3′‐hydroxy‐2′‐iodoalk‐1′(Z)‐enyl)furan‐2(5H)‐one derivatives via selective iodohydroxylation of non‐heteroatom‐substituted allenes, i.e., 4‐allenyl‐2(5H)furanones, has been developed. The regio‐ and stereoselectivity of this reaction may be controlled by the electronic and steric effects of the furanone ring. 相似文献
17.
Xiaodong Yang Yue She Ya Chong Huichun Zhai He Zhu Baohua Chen Guosheng Huang Rulong Yan 《Advanced Synthesis \u0026amp; Catalysis》2016,358(19):3130-3134
Direct strategies for the iodothiocyanation and iodonitration of allenes have been developed. In this process, potassium thiocyanate/silver nitrite and molecular iodine are used as the source of SCN, ONO2 and iodine to provide the desired products in moderate to good yields with high stereoselectivity.
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19.
Bastien Doumche Alain Archelas Roland Furstoss 《Advanced Synthesis \u0026amp; Catalysis》2006,348(14):1948-1957
The hydrolytic kinetic resolution of five glycidaldehyde acetal derivatives was examined using the recombinant Aspergillus niger epoxide hydrolase as biocatalyst. This could successfully be performed, at room temperature, using solely demineralised water as solvent and following a two‐phase methodology allowing us to operate at a global substrate concentration as high as 200 g/L in the reactor. The observed E values were shown to be modest to excellent, depending on the structure of the acetal moiety, indicating that it is possible to achieve this resolution very efficiently just by choosing the right substituents. Both the unreacted (R)‐epoxide and the formed (S)‐diol could thus be obtained in good to excellent ee (ee>99 % for the epoxide). For the best substrates, the reaction could be performed within a few hours by using a biocatalyst over substrate molecular ratio of about 9 to 10×10−4 mol %. The turnover frequency (TOF) as well as the total turnover number (TON) of the enzyme proved to be excellent as compared to chemical catalysts – reaching respectively values in the order of 6×102 mol sub/mol enz/min and 6×104 mol sub/mol enz. The space‐time yield of the best (two‐phase) reactor could thus reach a value as high as 56 g/L/hour. As a demonstration experiment, a 50‐g scale resolution of glycidaldehyde 2,2‐dimethyltrimethylene acetal was performed. 相似文献
20.
Alexis Mifleur Hlne Ledru Adrien Lopes Isabelle Suisse Andr Mortreux Mathieu Sauthier 《Advanced Synthesis \u0026amp; Catalysis》2016,358(1):110-121
Hydroalkoxylation of butadiene has been performed in the presence of nickel precatalysts associated with chelating diphosphine ligands. High butadiene conversions and selectivities forming alkyl butenyl ethers were obtained with low catalyst loading. Reactions were performed with a wide scope of primary alcohols including benzylic alcohol derivatives and bio‐sourced alcohols. In the same way, the scope of dienes that can be reacted according to this reaction has been also studied. Substituted butadiene derivatives have shown a lower reactivity compared to butadiene. Isoprene formed OC5 alkenyl ethers with a high regioselectivity for one branched isomeric form.