- Improving sustainability in ene-yne cross-metathesis for transformation of unsaturated fatty esters
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Ruthenium-catalyzed ene-yne cross-metathesis is performed with stoichiometric proportions of terminal olefins and alkynes. This is made possible by the continuous addition of the alkyne to the reaction mixture. The protocol allows the ene-yne cross-metathesis reaction to be carried out with long-chain terminal olefins and in a one-pot fashion with internal olefins after shortening by ethenolysis. The efficient conversion of renewable unsaturated fatty esters from bioresources into valuable conjugated 1,3-dienes of interest for further transformations is performed using this technique under mild conditions in dimethyl carbonate; an ecofriendly solvent. Environmentally ene-yne: A ruthenium-catalyzed ene-yne cross-metathesis reaction is performed with stoichiometric amounts of terminal olefins and alkynes. The alkyne is added to the reaction mixture continuously. The protocol allows ene-yne cross-metathesis reaction to be carried out with long-chain terminal olefins and with internal olefins after shortening by ethenolysis in dimethyl carbonate as solvent.
- Le-Ravalec, Virginie,Dupé, Antoine,Fischmeister, Cédric,Bruneau, Christian
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experimental part
p. 1291 - 1297
(2011/12/03)
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- Process for the synthesis of unsaturated alcohols
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A process of preparing an unsaturated alcohol (olefin alcohol), such as, a homo-allylic mono-alcohol or homo-allylic polyol, involving protecting a hydroxy-substituted unsaturated fatty acid or fatty acid ester, such as methyl ricinoleate, derived from a seed oil, to form a hydroxy-protected unsaturated fatty acid or fatty acid ester; homo-metathesizing or cross-metathesizing the hydroxy-protected unsaturated fatty acid or fatty acid ester to produce a product mixture containing a hydroxy-protected unsaturated metathesis product; and deprotecting the hydroxy-protected unsaturated metathesis product under conditions sufficient to prepare the unsaturated alcohol. Preferably, methyl ricinoleate is converted by cross-metathesis or homo-metathesis into the homo-allylic mono-alcohol 1-decene-4-ol or the homo-allylic polyol 9-octadecene-7,12-diol, respectively.
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Page/Page column 8-9
(2008/06/13)
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- Alkylvanadium and Alkylniobium Reagents, III. - Two Unconventional Chemical Methods for the Characterisation of Labile Transition Metal Complexes; Application to Allyl Derivatives of V(III), V(V), Cr(III), and Mn(II)
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Two little known chemical methods, the "Competition Constant Method" and the production of "Ligand Concentration/ Product Yield Diagrams", are suitable for the characterisation and identification of allyl and crotyl transition metal species prepared in so
- Kauffmann, Thomas,Bonrath, Werner,Beirich, Christoph,Li, Weichang,Pahde, Claudia,et al.
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p. 2093 - 2100
(2007/10/02)
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- Reactivity of hypervalent species of silicon: cleavage of the allyl-silicon bond
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The reactivities of the silicon-allyl bonds in two kinds of pentacoordinated silicon species CH2=CHCH2Si(o-O2C6H4)2-NMe4+ (1) and CH2=CHCH2Si(OCH2CH2)3N (2) has been compared.In the allyl transfer to carbonyl compounds under nucleophilic conditions (NaOMe, KF or Bu4NF) and electrophilic conditions (TiCl4, AlCl3, BF3) these two species show quite different behaviour.Complex 1 is activated by nucleophiles, while for 2 transfer occurs under electrophilic conditions.These results indicate that the reactivity of these species is a function of their overall charge and geometry.
- Cerveau, Genevieve,Chuit, Claude,Corriu, Robert J. P.,Reye, Catherine
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p. C17 - C20
(2007/10/02)
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