112391-53-4Relevant academic research and scientific papers
Diastereoselective access to trans -2-substituted cyclopentylamines
Joosten, Antoine,Lambert, Emilie,Vasse, Jean-Luc,Szymoniak, Jan
supporting information; experimental part, p. 5128 - 5131 (2011/01/05)
A highly diastereoselective synthesis of trans-2-substituted cyclopentylamines via a tandem hydrozirconation/Lewis acid-mediated cyclization sequence applied to butenyl oxazolidines is described. The method allows an easy preparation of diversely substituted cyclopentylamines which appear to be useful synthetic intermediates. This was further illustrated by the syntheses of (±)-Rodocaine, (±)-trans-pentacin, and enantiomerically enriched trans-cyclopentane-1,2-diamine.
Ring-closing metathesis in methanol and water
Kirkland, Thomas A.,Lynn, David M.,Grubbs, Robert H.
, p. 9904 - 9909 (2007/10/03)
The ring-closing metathesis (RCM) of acyclic dienes in both methanol and water has been achieved through the use of water-soluble ruthenium alkylidenes. These alkylidenes react readily with acyclic olefins in protic solvents, but they do not cyclize α,ω-dienes because of the instability of the resulting methylidene. Successful cyclization has been achieved through simple substrate modification - incorporation of an olefin substituent allows cyclization to proceed in good yield. A methyl-substituted substrate was cyclized in 60% conversion in methanol, and the incorporation of a phenyl substituent resulted in nearly quantitative cyclization. Phenyl-substituted substrates are best suited for the reaction, as a more stable, active catalyst is regenerated upon each catalyst turnover. Using this methodology, 90% conversion of a water-soluble substrate to a substituted cyclopentene has been achieved in aqueous solution. This methodology has also been successfully applied to increase RCM yield in organic solvents.
Intramolecular Reactions of N-Nitrenes: Description of the Transition State Geometry for Addition to Alkenes
Atkinson, Robert S.,Grimshire, Michael J.
, p. 1135 - 1146 (2007/10/02)
Oxidation of the N-aminoquinazolones (10) and (11) generates the corresponding N-nitrenes which add intramolecularly to both double bonds.Although nitrene addition is stereospecifically cis, both faces of each double bond are attacked and consequently stereoisomers are formed.From the different selectivity of the N-nitrenes for the two double bonds in (10) and (11) by comparison with (15) and (24), respectively, and from a consideration of the stereoisomer ratios, it is concluded that concerted addition of the N-nitrene to the double bonds in (10) and (11) obtains via a transition-state geometry resembling that shown in (34).
