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1.
《Journal of organometallic chemistry》1987,331(1):113-119
The course of palladium-catalyzed oxidation of a terminal alkene by t-BuOOH or by O2/H2O is greatly modified when the allylic carbon bears a p-toluenesulfonyl substituent, and allylic oxidation results. Mechanistic explanations of this observation are proposed. 相似文献
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Lewis acid catalyst-tuned reactions of N′-(2-alkynylbenzylidene)hydrazides with diethyl phosphite are described. Isoquinolin-1-ylphosphonate is generated when copper triflate is utilized as catalyst, while 2-amino-1,2-dihydroisoquinolin-1-ylphosphonate is obtained in the presence of palladium acetate. 相似文献
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《Tetrahedron letters》1988,29(15):1833-1836
The two title compounds (1,2) have been prepared and some Diels-Alder reactions investigated. 相似文献
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Silylcarbenes are generated by the pyrolysis of 1,1-bis(trimethylsilyl)-1-alkanols with elimination of trimethylsilanol. 相似文献
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(E)-1-Benzotriazolyl-3-(phenylsulphonyl)-1-propene ( 6 ) has been synthesized and its alkylation was studied. The results showed that the phenylsulphonyl group is a more powerful α-directing group than the benzotriazolyl group in the corresponding 1,3-dihetero-stabilized allyl anion. 相似文献
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New chiral sulfoxide-1,3-oxazoline ligands have been developed as chiral ligands for Lewis acid-catalyzed asymmetric Diels-Alder reactions. The use of chiral sulfinyl 1,3-oxazoline ligands in copper(II)-catalyzed asymmetric Diels-Alder reactions provided an endo cycloadduct as a major product with moderate enantioselectivity. A rationale is proposed for the mechanism of the asymmetric induction. 相似文献
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Dr. Siegfried H. Weber Wolf Arnold Lucien H. Chopard-dit-Jean Marc Montavon 《Monatshefte für Chemie / Chemical Monthly》1975,106(2):491-497
The title compound (1) is hydrolysed at pH=0–2 to the new compounds 1-thiocarbamoyl-5-methyl-3.3-diphenylpyrrolidin-2-one (3) and the tetrahydrotriazine derivative (4). These compounds, together with 5-methyl-3.3.-diphenylpyrrolidin-2-imine (5), are the stable end-products of the reaction. The expected 5-methyl-3.3.-diphenyl-1-thiocarbamoyl-pyrrolidin-2-imine (6) is formed either as an intermediate or an end-product according to the conditions of hydrolysis. Its formation is analogous to that of the isomeric 5-methyl-3.3.-diphenyl-2-pyrrolidinylidene-thiourea (9) from 1-(N-methoxymethyl)-3-(5-methyl-3.3.-diphenyl)-2-pyrrolidinylidene)-thiourea (2) by cleavage of the methoxymethyl group. 相似文献
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Kazem D. Safa Farnaz Behmagham Khatereh Ghorbanpour 《Journal of organometallic chemistry》2011,696(9):1840-1844
The magnesium bromide-diethyl etherate-catalyzed ring-opening of (3-(naphthalen-2-yl)-2,2-bis(trimethylsilyl)oxiran 2 with thiophenols affords (1-trimethylsilylvinyl)sulfides 3 and the (1-bromovinyl)silane 4. Nucleophilic attack occurs regioselectively at the position α- to silicon. The compound 2 has been converted into the (1-trimethylsilylvinyl)amide 5 with an excess of acetonitrile and into the (1-trimethylsilylvinyl)acetate 6 with acetic acid/acetic anhydride. These reactions proceed with catalytic amounts of boron trifluoride-diethylether. Treatment of 2 with acetic acid alone gives naphthaldehyde. The epoxide 2 reacts also with MgBr2·OEt2, MeLi/CuI, HX (XBr or Cl) and LiAlH4 with nucleophilic attack at the bis(trimethylsilyl)-substituted carbon. 相似文献
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Asymmetric Diels-Alder reactions with 2H-azirines as dienophiles have been studied. Diastereoselective reactions with an enantiopure azirine 1b, bearing a chiral auxiliary, gave substituted bi- and tricyclic tetrahydropyridines in high yield and stereoselectivity, under the influence of a Lewis acid. The novel enantioselective [4+2] cycloaddition reaction of 3-benzyl-2H-azirine carboxylate with cyclopentadiene was investigated with various chiral Lewis acid complexes and provided the corresponding tetrahydropyridines in moderate to low yield and enantioselectivity. 相似文献
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Shahrukh T. Asundaria Hemant S. Patel Keshav C. Patel 《Monatshefte für Chemie / Chemical Monthly》2010,66(8):917-927
Abstract
Ten homopolyamides have been synthesized by polycondensation of the monomer 2,4-bis(6-chlorocarbonyl-2-naphthyloxy)-6-(4-methyl-1-piperazinyl)-s-triazine and different diamines such as 4,4′-biphenyldiamine, 4,4′-diaminobenzanilide, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenyl sulfone, 4,4′-diaminodiphenyl sulfonamide, 2,4-diaminotoluene, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, and ethylenediamine. All polyamides were characterized by solubility, density, viscosity measurements, IR, NMR spectroscopy, and thermogravimetric analysis. The products were found to possess high thermal stability. 相似文献14.
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[reaction: see text] A highly efficient carbonylative Suzuki-Miyaura coupling reaction of lactam-derived vinyl triflates and alkenylboronic acids afforded 2-(N-methoxycarbonylamino)-1,4-pentadien-3-ones as suitable substrates for the Nazarov reaction. The most competent Lewis acids for the Nazarov reaction were Cu(OTf)(2) (2 mol %) and Sc(OTf)(3) (3 mol %) in DCE, which provided the Nazarov products in excellent yield. As both the carbonylative coupling and the subsequent Nazarov reaction were high yielding, the overall methodology is a concise and efficient route to [1]pyrindine systems. 相似文献
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Ishmaeva E. A. Chachkov D. V. Vereshchagin Ya. A. 《Russian Journal of Organic Chemistry》2003,39(11):1553-1556
According to the results of ab initio quantum-chemical calculation 1-bis(dimethylamino)-4-bis(trimethylsilyl-2,3-diphosphabuta-1,3-diene exists as an E-isomer where electronic delocalization occurs involving donor dimethylamino and acceptor trimethylsilyl groups and also the multiple P = C bonds. 相似文献
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Frank Luderer Helmut Reinke Hartmut Oehme 《Journal of organometallic chemistry》1996,510(1-2):181-188
Treatment of 2,4,6-triisopropylbenzaldehyde with tris(trimethylsilyl)silylmagnesium bromide (2) gives 2,4,6-triisopropylphenyl-tris(trimethylsilyl)silyl-methanol (3) in approximately 70% yield and E-3,4-bis(2,4,6-triisopropylphenyl)-1,1,2,2-tetrakis(trimethylsilyl)-1,2-disilacyclobutane (5) (15%). 5 is the [2 + 2] head-to-head cyclodimer of the transient 1,1-bis(trimethylsilyl)-2-(2,4,6-triisopropylphenyl)silene (4), formed by trimethylsilanolate elimination according to a Peterson mechanism from the magnesium alkoxide, derived from the alcohol 3. Deprotonation of 3 with McLi at low temperature in ether produces a complex mixture of products, the main constituents being the silene dimer 5 (10%) and bis(trimethylsilyl)-2,4,6-triisopropylbenzyl-trimethylsiloxysilane (10) (60%), which is formed by readdition of the eliminated lithiumtrimethylsilanolate at the Si=C bond of 4. The deprotonation of 3 with McMgBr or PhMgBr (activated by LiBr) in THF at room temperature results in the formation of the polysilane (Me3Si)3SiSi(SiMe3)2CH2(2,4,6-C6H2iPr3) (13). Its generation indicates that there exists an equilibrium between the magnesium alkoxide derived from the alcohol 3 on one side, and the magnesium silanide 2 and 2,4,6-triisopropylbenzaldehyde on the other side. Possible pathways of the formation of the compounds mentioned, as well as of further by-products, are discussed. The 1,2-disilacyclobutane 5 is characterized by an X-ray crystal structure analysis. 相似文献
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The asymmetric addition of alkyl radicals to (1R,2S,5R)-2-(1-methyl-1-phenylethyl)-5-methylcyclohexyl-2H-azirine-3-carboxylate (1) yielding the corresponding 2-alkylaziridine-2-carboxylates has been investigated. High diastereoselectivities and good yields were obtained in the addition of primary alkyl radicals to azirine 1, while secondary radicals gave a lower dr. The influence of Lewis acids was also investigated; 10 mol% of CuCl were found to increase the dr. 相似文献