Results 161 to 170 of about 3,168 (214)
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Asymmetric Ring‐Closing Metathesis with a Twist
Angewandte Chemie International Edition, 2009AbstractA double flip! The catalyst shown, with a molybdenum stereocenter and monodentate ligands (Si=SitBuMe2), promotes asymmetric ring‐closing metathesis of a broad range of substrates. Its unprecedented activity originates from its structural fluxionality, which enables double inversion at the metal center in the course of a single catalytic cycle.
Hendrik F T, Klare, Martin, Oestreich
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A Ring-Closing Metathesis Strategy to Phosphonosugars
Organic Letters, 2001[reaction: see text]. Syntheses of cyclic phosphonate (phostone) analogues of carbohydrates containing a phosphorus atom at the anomeric position are described. The ring-closing metathesis reaction of mixed allylic phenyl esters of allylphosphonic acid 2 and 22 generates the six-membered allylic phosphonates 3 and 23 in excellent yields.
D S, Stoianova, P R, Hanson
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Solvents for ring-closing metathesis reactions
Chemical Communications, 2008A study of the influence of eight diverse solvents on a Grubbs II-catalysed ring-closing metathesis (RCM) reaction reveals a complex dependence of the different reaction steps on the solvent and suggests acetic acid as a useful solvent for RCM reactions.
Claire S, Adjiman +3 more
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Ring-Closing Metathesis Approach to Dictyostatin
Organic Letters, 2005[reaction: see text] An esterification/ring-closing metathesis approach to dictyostatin and discodermolide is introduced. The approach provides for facile fragment coupling of two main segments of these natural products at the C10-C11 alkene with high to complete Z-selectivity.
Cyrous O, Kangani +2 more
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Ring-Closing Metathesis in Carbohydrate Annulation
Angewandte Chemie International Edition, 1998Even eight-membered rings (such as in 2) can be formed by ring-closing metathesis of glucose derivatives such as 1. Enantiomerically pure tricyclic spiro compounds can also be prepared.
Holt, DJ +7 more
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Enamide−Olefin Ring-Closing Metathesis
Organic Letters, 2001[reaction: see text] The first examples of ring-closing metathesis reactions of olefin-containing enamides using ruthenium-based catalysts have been demonstrated. A preliminary investigation into the scope and limitations, leading to protected five- and six-membered cyclic enamides, will be presented.
Kinderman, S.S. +4 more
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Oligomers as Intermediates in Ring-Closing Metathesis
Journal of the American Chemical Society, 2007Oligomerization is kinetically favored in RCM reactions catalyzed by RuCl2(PCy3)(IMes)(CHPh), for a range of unhindered α,ω-dienes leading to large or medium-sized rings, even at dilutions designed to minimize intermolecular reaction. Reversible metathesis (i.e., ethenolysis) is inhibited by rapid volatilization of ethylene.
Jay C, Conrad +6 more
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Ring closing metathesis of unprotected peptides
Chemical Communications, 2017Brønsted acid masking of unprotected peptide sequences facilitates high yielding Ru-alkylidene catalysed RCM to cyclic dicarba peptidomimetics in solution.
Ellen C. Gleeson +2 more
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Synthesis of Sultones by Ring Closing Metathesis
Synlett, 2002AbstractFor Abstract see ChemInform Abstract in Full Text.
Sandra Karsch, Pia Schwab, Peter Metz
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Ring‐Closing Metathesis in Aqueous Micellar Medium
Chemistry – A European Journal, 2011Underwater exploration: The ring-closing metathesis of N,N-diallyltosylamine (DATs) and diallyldiethyl malonate has been studied in aqueous micellar medium, at room temperature, in the presence of four different gemini cationic surfactants and various ruthenium catalysts.
Laville, Lionel +4 more
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