Amination manganese-catalyzed

Without additives, radical formation is the main reaction in the manganese-catalyzed oxidation of alkenes and epoxide yields are poor. The heterolytic peroxide-bond-cleavage and therefore epoxide formation can be favored by using nitrogen heterocycles as cocatalysts (imidazoles, pyridines , tertiary amine Af-oxides ) acting as bases or as axial ligands on the metal catalyst. With the Mn-salen complex Mn-[AI,AI -ethylenebis(5,5 -dinitrosalicylideneaminato)], and in the presence of imidazole as cocatalyst and TBHP as oxidant, various alkenes could be epoxidized with yields between 6% and 90% (in some cases ionol was employed as additive), whereby the yields based on the amount of TBHP consumed were low (10-15%). Sterically hindered additives like 2,6-di-f-butylpyridine did not promote the epoxidation. 

F. Calderazzo, The Manganese-Catalyzed Carbonylation of Amines, Inorg. Chem. 4, 293-296 (1965). 

Mechanisms in manganese-catalyzed oxidation of alkenes with H2O2 (pyridyl, quinoline, polypyridyl amine, trimethyltriazacyclononane, tet-... 

Aziridination of Alkenes. Iron- and manganese-porphyrin corrqilexes catalyze the reaction of PhI=NTs with alkenes to form the corresponding fV tosylaziridines. Mn(TPP)Cl is generally a better catalyst than the analogous iron complex, affording 80% of the aziridine from the reaction with styrene (eq 11). Good yields are also obtained in the manganese-catalyzed reactions with 1,1-and l,2-diphenylethylenes. Yields of aziridines derived from aliphatic alkenes remain low and are complicated by the formation of allylic amines. 

Fev=0 and Mnv=0 have also recently emerged as plausible reactive intermediates in the oxidation of hydrocarbons by iodosylbenzene, amine N-oxide, percarboxylic acids, hypochlorites, etc. catalyzed by iron or manganese porphyrins. Current opinion favors Fev=0 species as the active oxidant in cytochrome P-450 monooxygenases.54 55... 

Asymmetric imidations of aryl alkyl sulfides with [(tosylimino)iodo]ben-zene, catalyzed by various chiral (salen)manganese(III) complexes, have been investigated in some detail [31,32]. The influence of catalyst structure, solvent, temperature, 3°-amine AT-oxides, and the presence of molecular sieves on product yields and the enantioselectivity of imidation with 17 was evaluated. Enan-tioselectivities as high as 90 % ee and 97 % ee with methyl 2-nitrophenyl sulfide and methyl 2,4-dinitrophenyl sulfide, respectively, were achieved. 

Polyphenylene oxide. Oxidative polymerization of 2,6-xylenol to the engineering resin polyphenylene oxide (PPO) is catalyzed by copper and manganese amines. Pyridine is a typical amine used in the polymerization. 

The aziridination of olefins, which forms a three-membered nitrogen heterocycle, is one important nitrene transfer reaction. Aziridination shows an advantage over the more classic olefin hydroamination reaction in some syntheses because the three-membered ring that is formed can be further modified. More recently, intramolecular amidation and intermolecular amination of C-H bonds into new C-N bonds has been developed with various metal catalysts. When compared with conventional substitution or nucleophilic addition routes, the direct formation of C-N bonds from C-H bonds reduces the number of synthetic steps and improves overall efficiency.2 After early work on iron, manganese, and copper,6 Muller, Dauban, Dodd, Du Bois, and others developed different dirhodium carboxylate catalyst systems that catalyze C-N bond formation starting from nitrene precursors,7 while Che studied a ruthenium porphyrin catalyst system extensively.8 The rhodium and ruthenium systems are... 

Among the first reports was the investigation of an iron-catalyzed oxidation system in 1997. ESI-MS was used to characterize the intermediate [Fe "-TPA(OOH)]2 in the stereospecific hydroxylation of alkanes by hydrogen peroxide (TPA, tris(2-pyridyl-methyl)amine) [35]. It is unique among oxidation reactions studied by ESI-MS in that all other reports address manganese- or vanadium-catalyzed systems. 

The most important applications of peroxyacetic acid are the epoxi-dation [250, 251, 252, 254, 257, 258] and anti hydroxylation of double bonds [241, 252, the Dakin reaction of aldehydes [259, the Baeyer-Villiger reaction of ketones [148, 254, 258, 260, 261, 262] the oxidation of primary amines to nitroso [iJi] or nitrocompounds [253], of tertiary amines to amine oxides [i58, 263], of sulfides to sulfoxides and sulfones [264, 265], and of iodo compounds to iodoso or iodoxy compounds [266, 267] the degradation of alkynes [268] and diketones [269, 270, 271] to carboxylic acids and the oxidative opening of aromatic rings to aromatic dicarboxylic acids [256, 272, 271, 272,273, 274]. Occasionally, peroxyacetic acid is used for the dehydrogenation [275] and oxidation of aromatic compounds to quinones [249], of alcohols to ketones [276], of aldehyde acetals to carboxylic acids [277], and of lactams to imides [225,255]. The last two reactions are carried out in the presence of manganese salts. The oxidation of alcohols to ketones is catalyzed by chromium trioxide, and the role of peroxyacetic acid is to reoxidize the trivalent chromium [276]. 

From the viewpoints of reaction mechanism and efficiency in organic synthesis, oxidation of phenols with dioxygen catalyzed by cobalt-, manganese- and related metal-amine complexes has been studied . In particular, much effort has been directed toward constructing new efficient catalysts by a combination of metals with... 

Another reaction of type 3 is the formation of sym-dialkylureas from primary amines and CO catalyzed by manganese carbonyl complexes ... 

IRON(III) AND MANGANESE(IIl) TETRA-ARYLPORPH YRINS CATALYZE THE OXIDATION OF PRIMARY AROMATIC AMINES TO THE CORRESPONDING NITRO DERIVATIVES... 

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