Synthesis and characterization of manganese(III) and high-valent manganese-oxo complexes and their roles in conversion of alkenes to cyclic carbonates

Oxidative carboxylation of olefins with CO2: environmentally benign access to five-membered cyclic carbonates

“…Next, ring opening of the epoxide through nucleophilic attack by CO 2 In 2015, Ghosh's research team developed a hexacoordinate manganese(III)-complex 8 catalyzed direct synthesis of cyclic carbonates 10 via oxidative carboxylation of the corresponding olens 9 in the presence of TBAB as a co-catalyst. 30 Screening of various oxidants such as H 2 O 2 , PhIO, TBHP, MeCO 3 H, Py-Noxide, and m-CPBA; 1.5 equiv. TBHP was found to be ideal for each equivalent of olen at 100 C. The reactions were carried out in dry acetonitrile under 17 atm pressure of CO 2 and provided the target carbonates 10 with yield ranging from 10% to 48% along with considerable amounts of undesired epoxides (Scheme 6).…”

Hybrid Metalloporphyrin Magnetic Nanoparticles as Catalysts for Sequential Transformation of Alkenes and CO2 into Cyclic Carbonates

“…[44][45][46][47][48] Alternatively, synthetic metalloporphyrins have been described as excellent cytochrome P450 biomimeticc atalysts to selectivelyp romote olefin epoxidation in as ustainable fashion. [65][66][67][68][69][70] Therefore,m ore robustc atalysts such as heterogeneous and/orb iphasic systems have been lately developed,n amely those based on metal oxides, [71,72] supported gold catalysts, [73][74][75] sodium phosphotungstate, [76] and ionic liquids, [77] most of them using alkyl hydroperoxides as oxygen donors. [65][66][67][68][69][70] Therefore,m ore robustc atalysts such as heterogeneous and/orb iphasic systems have been lately developed,n amely those based on metal oxides, [71,72] supported gold catalysts, [73][74][75] sodium phosphotungstate, [76] and ionic liquids, [77] most of them using alkyl hydroperoxides as oxygen donors.…”

“…[49][50][51][52][53][54][55][56][57][58][59][60][61][62] Despite such advances, the designo fe fficient catalytic systems able to sequentially promote olefin epoxidation followed by CO 2 addition to epoxides is ag reat challenge [63,64] and further studies are still required to overcomes everal issues related to the instabilityo fh omogeneousc atalysts and the selectiono fa ppropriate oxidants. [65][66][67][68][69][70] Therefore,m ore robustc atalysts such as heterogeneous and/orb iphasic systems have been lately developed,n amely those based on metal oxides, [71,72] supported gold catalysts, [73][74][75] sodium phosphotungstate, [76] and ionic liquids, [77] most of them using alkyl hydroperoxides as oxygen donors. Nevertheless, to the best of our knowledge,t here are no reports on the application of heterogeneousm etalloporphyrin-based recyclable catalysts to promote the sequential transformation of olefins into cyclic carbonates, by using green oxidants such as O 2 or H 2 O 2 .F rom the existing literature and our own previouse xperience, the introduction of halogen atomsa tt he metalloporphyrin's macrocycle structure is known to enhance their catalytic activity and stabilityinboth epoxidation [78][79][80] and CO 2 addition to epoxides.…”

Oxidative Carboxylation of 1-Decene to 1,2-Decylene Carbonate

“…However, the epoxidation and the cycloaddition of CO 2 to an epoxide has been mainly studied separately and only a limited amount of literature is available for an integrated approach [3,[7][8][9][10][11][12][13][14][15][16][17][18][19]. Most of these studies used tert-butyl hydroperoxide (TBHP) [3,10,13,14,[16][17][18] or hydrogen peroxide [9,10,17,19] as the oxidant. Due to the improved atom efficiency and green nature, molecular oxygen would be the preferred, albeit more challenging, oxidant.…”