81748-00-7Relevant academic research and scientific papers
Catalytic oxidation of alcohols with novel non-heme N4-tetradentate manganese(ii) complexes
Vermaak, Vincent,Young, Desmond A.,Swarts, Andrew J.
, p. 16534 - 16542 (2018/12/05)
We report the preparation and characterisation of a series of novel non-heme N4-tetradentate Mn(OTf)2 complexes of the type, [(L)MnOTf2], where L = R,R and S,S enantiomers of BPMCN, its 6-methyl and 6-bromo derivatives as well as the novel ligand BMIMCN (BPMCN = N,N′-dimethyl-N,N′-bis(2-pyridylmethyl)-(R,R/S,S)-1,2-diaminocyclohexane, BMIMCN = N,N′-dimethyl-N,N′-bis(1-methyl-2-imidazolemethyl)-(R,R/S,S)-1,2-diaminocyclohexane). Solid state structural analysis of the BMIMCN-ligated Mn-triflate complexes (R,R-C4 and S,S-C4) revealed opposite helicity but identical metal site accessibility. This feature was exploited in the catalytic oxidation of primary and secondary alcohols, with hydrogen peroxide as oxidant and acetic acid as co-catalyst. Complexes R,R-C4 and S,S-C4 displayed the highest activity in benzyl alcohol oxidation, attributed to the electron-donating property of the BMIMCN ligand. Complex S,S-C4, displayed high activity for a variety of primary alcohol substrates, but the reaction suffered from reduced selectivity and side-reactions due to the presence of acetic acid. In contrast, secondary alcohol substrates could be oxidised to the corresponding ketone products in excellent isolated yields under mild reaction conditions and short reaction times.
Catalytic and mechanistic studies into the epoxidation of styrenes using manganese complexes of structurally similar polyamine ligands
Ilyashenko, Gennadiy,De Faveri, Giorgio,Follier, Thomas,Al-Safadi, Rawan,Motevalli, Majid,Watkinson, Michael
, p. 1124 - 1134 (2014/02/14)
Two structurally similar polyamine ligands (7 and 8) have been prepared, which differ only by the presence of either a secondary or tertiary nitrogen donor within their N5 donor set. The ligands, in combination with iron and manganese salts, have been screened for their efficacy as catalysts for the epoxidation of styrene, using both hydrogen peroxide and peracetic acid as oxidants. Clear differences in activity between the two systems were observed, with 7 proving most effective in the presence of MnSO4 with H 2O2, whereas ligand 8 proved to be effective with Mn(OTf)2, MnCl2 and Mn(ClO4)2 using peracetic acid as the oxidant. A Hammett analysis of the initial rate kinetics of the optimal systems, combined with analysis by UV-vis spectroscopy, indicates that the small structural differences in the ligands elicit profound changes in the nature of the active species formed. The Royal Society of Chemistry.
PROCESS FOR COUPLING EPOXIDES AND CARBON DIOXIDE
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, (2012/10/23)
The present invention relates to a process for preparing carbonates by reacting propylene oxide, ethylene oxide, styrene oxide and/or cyclohexene oxide with carbon dioxide in the presence of one or more catalysts of the formula I where R1 is hy
EPR spectroscopic trapping of the active species of nonheme iron-catalyzed oxidation
Lyakin, Oleg Y.,Bryliakov, Konstantin P.,Britovsek, George J. P.,Talsi, Evgenii P.
supporting information; experimental part, p. 10798 - 10799 (2009/12/04)
(Graph Presented) The key intermediate of a bioinspired iron catalyst for selective hydrocarbon oxidation based on hydrogen peroxide and an iron complex with a tetradentate aminopyridine ligand was trapped by EPR. On the basis of EPR and reactivity data this intermediate is tentatively proposed to be an oxoiron(V) complex.
