Ring closing metathesis studies
Ring-closing metathesis towards a formal synthesis of Taxol
... 4 as a development candidate in 1977. Activity shown against the then new MX-1 and CX-1 mammary and colon xenografts in nude mice were also proved. The interest in this compound increased significantly in 1979 when ...
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SYNTHESIS OF SOME CYCLITOLS AND AMINOCYCLITOLS BY USING RING CLOSING METATHESIS
... D -gluco, β- D -gluco, α- D -galacto, β- D -galacto, α- D -manno, β- D -manno, α- L -fuco, and β- L -fuco configured aminocyclopentitols etc. Recent studies by Reymond and co- workers revealed that the N-benzyl ...
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Toward a simulation approach for alkene ring-closing metathesis : scope and limitations of a model for RCM
... the metathesis-active species are quenched before samples are ...secondary metathesis events that may be complex in nature 2 and demon- strates the difficulty involved in using reaction yields from the ...
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Exploring the ring-closing metathesis for the construction of the solomonamide macrocyclic core: identification of bioactive precursors
... additional studies, involving a combination of spectroscopic and theoretical studies (QM J based analysis and DFT J/ 13 C calculations), which resulted in the proposal of the depicted absolute ...
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Mapping the potential energy surfaces for ring-closing metathesis reactions of prototypical dienes by electronic structure calculations
... alkene metathesis reactions has grown spectac- ularly since well defined and air stable metal-alkylidene catalysts 1a–1c became commercially ...on ring-closing metathesis (RCM) reactions, 2 ...
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Methods for Enhancing Ring Closing Metathesis Yield in Peptides: Synthesis of a Dicarba Human Growth Hormone Fragment
... Future studies in the area should separately examine each stereoisomer of 6 to delineate the differences in biological activity which may be arising from the geometric differences in the dicarba ...
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Ring closing metathesis reactions of α methylene β lactams : application to the synthesis of a simplified phyllostictine analogue with herbicidal activity
... Conclusions These studies show for the first time that -methylene-- lactams can undergo RCM reactions. The methodology provides a practical strategy for the assembly of lactam-fused, 12-membered rings in a ...
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STEREOSELECTIVE TOTAL SYNTHESIS OF (-)-ASPINOLIDE, SYRIBUTINS, RING-CLOSING METATHESIS APPROACH TO THE SYNTHESIS OF ILEXLACTONE AND SYNTHESIS OF STRUCTURALLY DIVERSE COMPOUNDS VIA BAYLIS-HILLMAN REACTION
... Equation 1 The major product was unambiguously proved to be an E,E-isomer from NMR studies. In all cases, the olefinic proton signals for E,Z and E,E isomers were clearly distinguishable in their 1 H NMR spectra, ...
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Ruthenium Olefin Metathesis Complexes: Catalyst Development and Mechanistic Studies
... olefin metathesis catalysts have made impressive advances over the last several decades, several important areas of catalyst development remain (Figure ...olefin metathesis processes has been an ongoing ...
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Synthetic studies on the bryostatin B-ring
... that metathesis had not taken place and that O-deallylation had also occurred alongside ...undergo ring-closing-metathesis and as such it would remain in the reaction until aqueous work-up, ...
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Phyllostictine A ring assembly via ring closing metathesis
... Chapter 2 describes work towards the construction of the macrocyclic rings found in phyllostictine A. As a result α-methylene-β-lactams have been shown, for the first time, to participate in RCM reactions. Formation of ...
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Cross Metathesis and Ring-Closing Metathesis Reactions of Modified Amino Acids and Peptides.
... The organic layer was washed with aqueous saturated sodium bicarbonate (10 mL), saturated ammonium chloride (10 mL), and saturated brine solution (10 mL), the organic [r] ...
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Multiple Olefin Metathesis Polymerization That Combines All Three Olefin Metathesis Transformations: Ring-Opening, Ring-Closing, and Cross Metathesis
... ~S7~ General procedure of Tandem RO/RCM polymerization The monomer (0.1 mmol) was put into a 2 mL sized vial with septum and purged with Ar-gas. Degassed THF was added to the vial and stirred. A solution of ...
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Central core Uprolides a survey of some ring closing metathesis approaches
... The residue was purified by chromatography (1:1 petroleum ether/ethyl acetate) followed by crystallization to give diol 7 (3.1 g, 25.4% overall) as colorless solid.. DCM was [r] ...
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Highly functionalized piperidines via ring-closing metathesis of dehydroamino acids
... 115 that high temperatures were required for the reaction to proceed, resulting in only 12% of the aldehyde after silica gel purification. Moreover, the aldehyde rapidly decomposed upon standing at room temperature. In ...
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Synthesis of fluoride- and trifluoromethyl- substituted heterocycles via ring-closing metathesis
... (ring-closing metathesis, RCM) te gebruiken als algemene methode om fluoride- en trifluormethyl-gesubstitueerde olefinen om te zetten in de overeenkomstige gefluoreerde ...
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Synthesis of a Ribose-Incorporating Medium Ring Scaffold via a Challenging Ring-Closing Metathesis Reaction.
... medium ring formation as the tri-TMS-protected substrate (1f) did not ...fused ring protecting group on the tetrahydrofuran diol gave a very small yield of medium ring product which was an ...
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Functional metathesis catalyst through ring closing enyne metathesis: one pot protocol for living heterotelechelic polymers
... (Sigma! Aldrich).! The! labelled!polymer!was!purified!by!JAI!LCI9130!recycling!GPC!with!CHCl 3 !as!eluent.!The!system!consisting! of! two! linear! JaigelI2H! and! JaigelI1H! columns.! Si[r] ...
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Synthesis of benzo-fused heterocycles using isometerization and ring-closing metathesis reactions
... 142e 2 M 180 86 * not isolated, used directly in the next step Overall, the yields of the Claisen rearrangements were poor to moderate, with an average yield of just 62 %. The heating methodology employed does not, ...
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Synthesis of cage heterocycles containing tetrahydrofuran and pyran ring system via Grignard addition and ring-closing metathesis
... derivative 14 in the presence of Grubbs second generation (G-II, 5 mol%) catalyst in dry DCM at RT for 7 h gave the cage pyran 16 in 84% yield (Scheme II). The structure of the RCM product 16 was supported by spectral ...
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