Results 191 to 200 of about 4,073,254 (239)
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Olefin cross-metathesis with vinyl halides
Chemical Communications, 2008The first successful example of olefin cross-metathesis with chloroalkenes is reported.
Volodymyr, Sashuk +3 more
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Chemical & Engineering News Archive, 2007
OLEFIN CROSS-METATHESIS , the coupling of two distinct alkenes, is a useful synthetic organic reaction, but it has only rarely been achieved on solid phase. Researchers have now found that proper spacing between the polymer support and the tethered alkene makes the solid-phase reaction more feasible.
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OLEFIN CROSS-METATHESIS , the coupling of two distinct alkenes, is a useful synthetic organic reaction, but it has only rarely been achieved on solid phase. Researchers have now found that proper spacing between the polymer support and the tethered alkene makes the solid-phase reaction more feasible.
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Catalytic Nitrile-Alkyne Cross-Metathesis
Journal of the American Chemical Society, 2007The first catalytic cross-metathesis reaction of an alkyne with a nitrile is described. The nitride complex N⋮W(OC(CF3)2CH3)3(DME) undergoes reversible triple-bond metathesis reactions with alkynes (RC⋮CR; R = Et, 4-C6H4OMe), forming the alkylidyne complexes RC⋮W(OC(CF3)2CH3)3(DME) (R = Et, 4-C6H4OMe) along with the corresponding nitrile RC⋮N. This has
Andrea M, Geyer +3 more
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Cross-Metathesis Assisted by Microwave Irradiation
The Journal of Organic Chemistry, 2005Microwave irradiation effectively accelerates cross-coupling metathesis reactions between deactivated olefins. Reactions have been carried out with the phosphine-free Hoveyda-Grubbs catalyst and the "second generation Grubbs' catalyst." While there have been reports that a "microwave effect" is observed in various transformations, the accelerations we ...
Frédéric C, Bargiggia +1 more
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Tandem dienyne cross-metathesis/ring-closing metathesis
Tetrahedron Letters, 2001Abstract Tandem enyne cross-metathesis/ring-closing metathesis between terminal alkynes and 1,5-hexadiene has been demonstrated using the 1,3-dimesityl-4,5-dihydroimidazol-2-ylidene-substituted ruthenium benzylidene complex. Synthesis of 2-substituted 1,3-cyclohexadienes using this one step tandem reaction is reported.
Jason A Smulik, Steven T Diver
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Cross Metathesis Route in Sphingomyelin Synthesis
Chemistry Letters, 2004Abstract Cross metathesis reaction of short chain Boc sphingosine using Grubbs’ 2nd generation catalyst proceeded in stereoselective manner to afford Boc sphingosine in good yield. An efficient synthesis of sphingomyelin was achieved from the obtained Boc sphingosine using our own phosphorylation reagent.
Hiroko Hasegawa +4 more
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Cross‐Metathesis and Ring‐Closing Metathesis of Olefinic Monosaccharides.
ChemInform, 2003AbstractFor Abstract see ChemInform Abstract in Full Text.
Maarten H. D. Postema, Jared L. Piper
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Metathesis and cross-metathesis of 5-acetoxy- or 5-cyanonorbornene
Journal of Molecular Catalysis, 1992Abstract Ring-opening metathesis polymerization (ROMP) of 5-cyanonorbornene (CNB) with the catalyst system tungsten hexachloride/diethylaluminium ethoxide proceeds with high selectivity and activity (CNB:W = 10200:1). The three-component catalyst system tungsten oxytetrachloride/methylaluminoxane/tetraisobutyldialuminoxane is suitable for ...
E. Thorn-Csányi, Ch. Harder, B. Dahlke
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Ring closing metathesis and cross metathesis of carbohydrate derivatives
Tetrahedron Letters, 1998Abstract In connection with the synthesis of annonaceous acetogenins and analogs, RCM of unsaturated esters has been studied with the Grubbs benzylidene carbene catalyst to give 9 to 15 membered lactones in moderate to good yield. Cross metathesis between 2 carbohydrate derivatives and methyl undec-10-enoate is also reported.
Hanadi El Sukkari +2 more
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Cross-metathesis and ring-closing metathesis of olefinic monosaccharides
Tetrahedron Letters, 2002Cross-metathesis (CM) of a variety of carbohydrate-based C-6 and olefins with related C-1 and C-6 carbohydrate-based olefins proved to be unselective. CM was selective when an unhindered straight chain olefin was coupled with a carbohydrate-based C-6 olefin.
Maarten H.D. Postema, Jared L. Piper
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