Triazacyclononane Derivatives

C—H bond activation [94f], sulfoxidation [95] and the cis-dihydroxylation, and epoxidation of alkenes [94, 117]. 

Hydrogen peroxide decomposition by Mn-tmtacn complexes in CH3CN was shown to be suppressed effectively by addition of oxalate [94d] or ascorbic acid [94a] as co atalysts. Indeed the addition of these additives even in cootalytic amounts resulted in a dramatic enhancement in the epoxidation activity of the in situ prepared Mn-tmtacn complex [94d]. In general, fidl conversion was reached with less than 1 mol% of catalyst within 1 h. In addition to oxalic acid, several other bi- or polydentate additives, for example, diketones or diacids, in combination with Mn-tmtacn and H2O2 were found to favor alkene epoxidation over oxidant decomposition [94d]. Employing this mixed catalytic system, allylic alkenes (e.g., allyl 

Nevertheless, the system of De Vos and coworkers based on the use of oxalate buffer represented a major advance in the application of this catalyst and stimulated the search for other additives that could further improve the reactivity of this system. 

Recently Suss-Fink, Schul pin and coworkers have reported two tmtacn detivatives where one of the methyl groups has been replaced by a 2-methyl-butyl or 2-hydro-xybutyl group [105]. The catalytic activity was examined in the oxidation of Lndene and phenylethanol (racemic) in the presence of ascorbic acid [94] or oxalate [97]. Although moderate activity was observed (up to 300 t.o.n.), unfortunately only very low levels of enantioselectivity were achieved ( 17%). 

Kilic et al. have reported an alternative approach to controlling the stereochemical outcome of the epoxidation catalyzed by Mn-tmtacn complexes using substrate control via the hydroxyl group of allyhc alcohols and by varying the steric nature of the substituents on the alkene [106]. 

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The octahedral complexes, pale green [VmL], purple VlvL]PF6, and blue-black [VvL](C104)2, where L represents a l,4,7-tris(2-hydroxybenzyl)-l,4,7-triazacyclononane derivative, serve as an example where all one-electron redox processes are clearly metal centered as depicted in Eq. (6). Table III lists the complexes prepared (148b, 152, 153). 

Triazacyclononane derivatives, 24 56 Triazine-based antibiotics, 26 799 Triazine herbicides, 13 284, 321-322 Triazines, 18 769, 9 290-291 Triazines. See also, Environmental fate of triazines... 

On the other hand, in homogeneous epoxidation catalysis, De Vos et al. [6] have explored the properties of manganese (II) salts in the presence of triazacyclononane derivatives and... 

In the case of the Co(II) complex, the sixth coordination site on each metal is occupied by a water molecule. The stability toward oxidation of this complex is unusual because the Co(II) complex of the corresponding 1,4,7-triazacyclononane derivative, incorporating three pendant alcohol arms, readily oxidizes in air at neutral pH to form the corresponding Co(III) species (23). 

Several analogs of ferroquine have been developed, one of which is a ferrocene triazacyclononane derivative 37 (Figure 16) active against the chloroquine-resistant Plasmodium falciparum strain Dd2. ... 

Interestingly, in the light of the above results, CuCb complexes of some trApyrazolylborate or 1,4,7-triazacyclononane derivatives are active catalysts for the polymerization of 4-fluorophenol " ... 

Dinuclear Mn(IV) catalysts were successfully applied for the epoxidation of 4-benzoic acid and styrene in aqueous systems [18], for the epoxidation of styrene and dodecene in two-phase systems [19g] as weU as in methanol and acetone [17d, 19b,g,h], and for the epoxidation of olefins in acetonitrile [19i], aqueous acetonitrile [17f, 19c], acetone [17d, 19b,h], methanol [19i], and acetone-methanol-water mixtures [19j]. Enantioselective epoxidations of olefins have been reported for chiral triazacyclononane derivatives boimd to Mn(OAc2) 4 (H2O) in methanol [19k], Heterogenization of the Mn catalysts on silica for the epoxidation of styrene and cyclohexene, on zeolites for olefin epoxidation, and on a solid MnS04 H2O also for olefin epoxidation [20] has also been described. A polymeric structure bearing a dense arrangement of 1,4,7-triazacyclononane moieties can be synthesized by... 

Despite the fact that several related complexes of other metals have been described [30], only Mn triazacyclononane derivatives have been fixed onto soluble polymers and successfully applied in alkane oxidation so far [31]. 

Rational syntheses of multinuclear high-spin metal complexes with pyridine or 1,4,7-triazacyclononane-derived ligands 07BCJ608. 

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