Catalytic asymmetric epoxidation of unfunctionalized olefins using chiral (salen)manganese(III) complexes

Biocatalysis as an alternative for the production of chiral epoxides: A comparative review

“…Classic methods for the asymmetric epoxidation of styrene and derivatives ␤-Substituented styrene derivatives can be cis-or trans-aromatic alkenes. The asymmetric epoxidation of cis-alkenes can be achieved using the Katsuki-Jacobsen epoxidation, in which chiral Mn(III)-salen (2) catalysts have been introduced with NaOCl/PhIO as an oxidant in CH 2 Cl 2 at room temperature, giving good yields and higher selectivity (92-95% ee) (Scheme 4a) [11][12][13]82]. Either of the enantiomer can be produced by the change of the configuration of the catalyst.…”

“…This method has been widely applied in the epoxidation of cis-alkenes and many salen derivatives have been introduced. However, trans-styrene derivatives are not good substrates for this reaction in terms of enantioselectivity (<88% ee) [11,12]. The Shi epoxidation reaction has been successfully applied in the asymmetric epoxidation of trans-alkenes, which is catalyzed by the fructose-derived ketone (3, 20-30 mol%) and oxone in the mixture of water and acetonitrile, affording the corresponding (R, R)-oxides with 93-98% ee (Scheme 5a) [14,83,84].…”

“…The most prominent catalytic reaction is the Sharpless epoxidation which allows the asymmetric epoxidation of prochiral allylic alcohols [9,10]. Other state of the art protocols, such as the Katsuki-Jacobsen epoxidation of unfunctionalized cis-substituted alkenes [11][12][13], and the Shi's epoxidation of trans-substituted alkenes [14], provide valuable complements to the Sharpless epoxidation. The Jacobsen HKR is one of the most powerful approaches for kinetic resolution of epoxides [8,15].…”

Evaluating Binol-Aldehyde as a Chiral Derivatizing Agent for Diamines

“…Chiral vicinal diamines have been employed in the development of transition metal based catalysts [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16], organocatalysts [17][18][19][20] and pharmaceuticals [21]. Chiral derivatizing agents (CDA) continue to be an important and convenient tool for determining the enantiopurity of chiral compounds.…”

Oxidation of limonene catalyzed by Metal(Salen) complexes

“…Many Metal(Salen) derivatives, including chiral ones, have already been described and used in different chemical processes (Hobday and Smith, 1973;Ito et al, 1998). Salen complexes of Cr(III) (Samsel and Katsuki, 1985), Mn(III) (Srinivasan et al, 1986;Chang et al, 1994;Irie et al, 1991), Fe(III) (Jacob et al, 1989) and Co(III) (Reddy et al, 1995) have been shown to be active catalysts for olefinic oxidation.…”