نتایج جستجو برای: olefins

تعداد نتایج: 2875  

Journal: :Angewandte Chemie 2015
Peter K Dornan Zachary K Wickens Robert H Grubbs

A stereoselective synthesis of anti-1,2-diols has been developed using a multitasking Ru catalyst in an assisted tandem catalysis protocol. A cyclometalated Ru complex catalyzes first a Z-selective cross-metathesis of two terminal olefins, followed by a stereospecific dihydroxylation. Both steps are catalyzed by Ru, as the Ru complex is converted to a dihydroxylation catalyst upon addition of N...

Journal: :Molecules 2018
Agustina La-Venia Mirta P Mischne Ernesto G Mata

The gold-catalyzed intermolecular hydroalkylation of olefins with β-ketoesters represents a conceptually attractive and useful synthetic tool; however, it has been scarcely applied, remaining a challenge for chemists. The aim of the current study was to investigate the addition of these 1,3-diketo-compounds to alkenes under gold catalysis conditions, in order to establish the electronic and ste...

2015
Jawahar L. Jat Saroj Ranjan De Ganesh Kumar Adeniyi Michael Adebesin Shyam K. Gandham John R. Falck

Ti(IV)-salan 4 catalyzes the diastereo- and enantioselective monoepoxidation of conjugated dienes using 30% H2O2 at rt or below even in the presence of other olefins and adjacent stereocenters. Its enantiomer, ent-4, provides access to the opposite diastereomer or enantiomer. The resultant chiral allylic epoxides, and the triols derived from them, are versatile synthetic intermediates as well a...

2015
Hai T. Dao Chao Li Quentin Michaudel Brad D. Maxwell Phil S. Baran

A solution to the classic unsolved problem of olefin hydromethylation is presented. This highly chemoselective method can tolerate labile and reactive chemical functionalities and uses a simple set of reagents. An array of olefins, including mono-, di-, and trisubstituted olefins, are all smoothly hydromethylated. This mild protocol can be used to simplify the synthesis of a specific target or ...

A. Abbasi M. Masteri-Farahani M. Najafi V. H. Rodrigues

A two-dimensional nanolayered polyoxomolybdate, [4,4´-H2bipy] [Mo7O22].H2O (1), where 4,4´-bipy = 4,4´-bipyridine, was prepared and characterized by FT-IR and atomic absorption spectroscopies, transmission electron microscopy (TEM), X-ray single crystal and powder diffraction (XRD), and thermogravimetric analysis. The catalytic performance of 1 was assessed in the epoxidation of some olefins em...

Journal: :Journal of Synthetic Organic Chemistry, Japan 1968

2014
Yingguang Zhu Richard G. Cornwall Haifeng Du Baoguo Zhao Yian Shi

CONSPECTUS: Vicinal diamines are important structural motifs present in various biologically and chemically significant molecules. Direct diamination of olefins provides an effective approach to this class of compounds. Unlike well-established oxidation processes such as epoxidation, dihydroxylation, and aminohydroxylation, direct diamination of olefins had remained a long-standing challenge an...

Ti-MCM-41 was synthesized at pH 3, 7 and 11. The titanium content was determined by AAS and found to be 4%, 3.2% and 4.5%, respectively. In order to increase the titanium content in Ti-MCM-41, Ti(IV) ions were grafted onto Ti-MCM-41 using TiCl4 in toluene and Ti(OBu)4 in ethanol. The incorporation of Ti was determined to be 28% and 30%, respectively. The oxidation of olefins such as cyclopenten...

Journal: :Friction 2023

Abstract To utilize Cu-benzene-1,3,5-tricarboxylate (Cu-BTC) adsorbed lubricant oils in the self-lubricating field, adsorption properties of Cu-BTC on different 1-olefins must be clarified. In this work, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-undecene, and 1-dodecene were studied by Monte Carlo method experimentally. The limit for n-olefins was determined as 1-undecene isotherms. This sugges...

Journal: :Organometallics 2008
Donde R Anderson Thay Ung Garik Mkrtumyan Guy Bertrand Robert H Grubbs Yann Schrodi

The evaluation of ruthenium olefin metathesis catalysts 4-6 bearing cyclic (alkyl)(amino)carbenes (CAACs) in the cross-metathesis of cis-1,4-diacetoxy-2-butene (7) with allylbenzene (8) and the ethenolysis of methyl oleate (11) is reported. Relative to most NHC-substituted complexes, CAAC-substituted catalysts exhibit lower E/Z ratios (3:1 at 70% conversion) in the cross-metathesis of 7 and 8. ...

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