654071-51-9Relevant academic research and scientific papers
Titanium-Mediated Cyclopropanation of Nitriles with Unsaturated Grignard Reagents: Application to the Synthesis of Constrained Lysine Derivatives
Forcher, Gwéna?l,Clousier, Nathalie,Beauseigneur, Alice,Setzer, Paul,Boeda, Fabien,Pearson-Long, Morwenna S. M.,Karoyan, Philippe,Szymoniak, Jan,Bertus, Philippe
, p. 992 - 1006 (2015)
A comparative study of the titanium-mediated cyclopropanation of (benzyloxy)acetonitrile and Boc-protected cyanohydrin using unsaturated Grignard reagents (but-3-enyl- and pent-4-enylmagnesium bromides) is described. The best conditions to provide the cis and trans isomers of cyclopropylamines bearing unsaturation were identified and the alkene moiety was subjected to chemical modifications, as shown by the synthesis of orthogonally protected cis- and trans-2,3-methanolysine, cis-2,3-methanoornithine, and cis-2,3-methanohomo-lysine.
Rhodium-catalyzed synthesis of terminal alkenes
Paquet, Valerie,Lebel, Helene
, p. 1901 - 1905 (2007/10/03)
Terminal alkenes have been efficiently prepared via a rhodium-catalyzed olefination procedure using Wilkinson's catalyst in the presence of triphenylphosphine, 2-propanol and trimethylsilyldiazomethane. Optimized reaction conditions are described for aldehydes and ketones, as well as alternative work up procedures. Georg Thieme Verlag Stuttgart.
Rhodium-Catalyzed Methylenation of Aldehydes
Lebel, Helene,Paquet, Valerie
, p. 320 - 328 (2007/10/03)
The rhodium-catalyzed methylenation of aldehydes using trimethylsilyldiazomethane and triphenylphosphine produces a variety of terminal alkenes in excellent yields. These mild and nonbasic reaction conditions allow the conversion of enolizable substrates (keto aldehydes and nonracemic α-substituted aldehydes) to terminal alkenes without epimerization. Optimization of the reaction conditions led to the conclusion that a variety of rhodium(I) sources can be used as catalysts. The effect of the solvent on the reaction has also been studied, and it indicates that although the THF is the best solvent, other solvents may be used. The reactivity of the system is very much dependent on the nature of the phosphine reagent. The use of an easily removable phosphine is also described. Spectroscopic studies indicate that the reaction proceeds via an unusual mechanism which leads to the in situ formation of the salt-free phosphorus ylide, methylenetriphenylphosphorane.
Multicatalytic processes using diverse transition metals for the synthesis of alkenes
Lebel, Helene,Paquet, Valrie
, p. 11152 - 11153 (2007/10/03)
A series of cascade processes for the synthesis of alkenes from alcohols is described. Each individual step is catalyzed with a specific transition metal complex. The oxidation-methylenation one-pot procedure took place in the presence of a palladium and a rhodium catalyst to produce the desired terminal alkenes in high yields. A methylenation-ring-closing metathesis allowed the synthesis of cyclic alkenes from carbonyl derivatives, using the second-generation metathesis catalyst. Finally, an oxidation-methylenation-RCM process that involves up to three different transition metal catalysts in the same vessel is presented. Copyright
