Manganese Catalysts with C₁‐Symmetric N₄ Ligand for Enantioselective Epoxidation of Olefins

Abstract

Die Stetter‐Reaktion nutzt eine umgepolte Reaktivität zur katalytischen Bildung 1,4‐difunktionalisierter Produkte. Bei der vorgestellten ersten enzymatischen 1,4‐Addition ermöglicht das ThDP‐abhängige Enzym PigD eine anspruchsvolle asymmetrische intermolekulare Stetter‐Reaktion (siehe Schema).

Biologically inspired non-heme iron-catalysts for asymmetric epoxidation; design principles and perspectives

“…43 In parallel, their use as aliphatic alkene epoxidation catalysts useful in preparative scale was described by Jacobsen and co-workers. [53][54][55][56][57] After testing several amino acid derivatives, and N-protecting groups, the best result in terms of yield and enantioselectively was obtained using N-NPha-Ileu-OH (Figure 3). of H 2 O 2 and acetic acid as a key additive to ensure high product yields (Scheme 5).…”

“…48,49,57,59,60 Interestingly, Jacobsen and co-workers 61 62 The mechanism that emerged is shown in Scheme 6. AcOH has long been recognized to play a beneficial role in Mn catalyzed oxidation reactions.…”

Non-heme manganese complexes of C1-symmetric N4 ligands: Synthesis, characterization and asymmetric epoxidations of α,β-enones

“…Additionally, the oxidant and reaction temperature were examined using C1 as the catalyst. When H 2 O 2 was used as oxidant, 1,3-diphenyl-propenone was epoxidized with slightly lower yield and similar enantioselectivity ( Table 1, entry 1 vs 2) [28,40]. However, a comparable enantioselectivity was obtained after lowering the reaction temperature by prolonging the reaction time to 34 h ( Table 2, entries 3 vs 1).…”

“…The corresponding manganese complexes of general formula [Mn(OTf) 2 -(R,R'MPP)] C1eC4 were obtained by reaction of each ligand with Mn(CF 3 SO 3 ) 2 in CH 3 CN under an argon atmosphere (Scheme 1). Generally, this type of N4 ligands coordinate the manganese center in a cis-a topology [22,26,28,40].…”

Chiral Manganese Aminopyridine Complexes: the Versatile Catalysts of Chemo‐ and Stereoselective Oxidations with H2O2

“…Sun with co‐workers designed a family of Mn(II) complexes ( 6 , 7 and 8 , Figure ) bearing tetradentate N ‐donor ligands with benzimidazole moieties instead of pyridine ones, with various chiral backbones. It was found that 6 catalyzed the epoxidation of substituted chalcones with high enantioselectivity (up to 95 % ee , Table ), performing 300–500 turnovers.…”