Asymmetric Diel Reaction Lab Report

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Equ 13. 4-(5-nolyl)-Pyridinum Cation Containing CILs Catalyzed Aldol Reactions Equ 14. Amide Functionalized Proline based CILs Organocatalyst for Aldol Reactions 3.4. Asymmetric Diels-Alder reaction. In 1997, Howarth and his group80 reported first, the asymmetric Diels-Alder reaction by using dialkylimidazolium salts (chiral and achiral) as efficient organocatalyst between crotonaldehyde or methacrolein and cyclopentadiene. The enentiomeric excess was less than 5% and no such diastereoselectivity were observed. Here enantiomeric excess did not depends upon the ionic liquids chirality, both chiral CILs and achiral CILs gave the near about same results. After that time researchers have been tried to design and synthesized Lewis acid based …show more content…

The anionic CIL N-methylimidazolium (R)-camphorsulfonate was employed in the reaction with methyl vinyl ketone (Equ 19). After Michael addition, N-(3ꞌ-oxobutyl)-N-methylimidazolium (R)-camphorsulfonate was obtained. Using heterogeneous catalyst Ru/C in the hydrogenation reaction of this imidazolium cation functionalized carbonyl group to produce corresponding asymmetric alcohol gave moderate yield and enantioselectivity 80% ee was …show more content…

Enantioselective hydrogenation of keto functionalized ionic liquid. The field of asymmetric hydrogenation reactions using metal complexes has been well developed. These complexes are generated from assymmtric chiral ligands such as atropoisomeric binaphthyls and biphenyls. In 2007, Francio and group88 reported asymmetric hydrogenation reaction catalyzed by tropoiosmeric ligand based rhodium complex in presence of amino acid based CIL 71 as a chiral solvent. In this reaction the chirality of hydrogenated product arises from CILs and enantioselectivities up to 69% ee were observed (Equ 20). In 2008, the same group89 reported hydrogenation reaction using transition metal complex with racemic ligands instead of enantiopure ligands in presence of CILs. The same results were observed by using both the racemic ligands and enantiomerically pure ligands (Equ 20). These results were observed mainly due to the chiral poisoning by the CILs in racemic 2,2ꞌ-bis(diphenylphosphanyl)-1,1ꞌ-binaphthyl ligands which was connecting with metals. Equ 20. Enantioselective hydrogenation in amino acid-based CILs. 3.6. Biginelli

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