1,4,7-Triazacyclononane moieties

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... 

Previous to this study, the Tolman group had also reported on complexes similar to the XYL-H model system which employ dinucleating triazacyclononane moieties linked by m- orp-xylyl groups. These systems form either (i-T) T] -peroxodicopper(II) complexes or bis-ji-oxo-dicopper(III) complexes, depending on conditions such as solvent, temperature, and concentration. Based on this report, the p.-Ti iri -peroxodicopper(II) complex leads to arene hydroxylation, similar to the XYL-H system, whereas the bis-ji-oxo-dicopper(IH) complex favors monooxygenation leading to N-dealkylation. 

An easily accessible hexadentate derivative of tacn, namely 1,4, 7-tris(u-aminobenzyl)- 1,4,7-triazacyclononane (tabtacn), forms a 1 1 complex [Cd(tabtacn)](C104)2 0.5 H20 Pc2 njPna2, Z = 4) with a distorted trigonal prismatic CdN6 core. The Cd—N bonds to the N donors in both the tacn moiety and in the aniline pendant arms are very similar in a rather narrow range (rav(Cd—N) 237 pm).178 Both solution and solid-state H, 13C, and 113Cd NMR spectra have been measured and analyzed with respect to details of the stereochemistry and to dynamics in solution. 

In pursuit of the imaging objective, In(III) has been incorporated into ligand 79, which involves the macrocycle 1,4,7-triazacyclononane with three pendant acetate moieties (88). 

Thianthrene radical cation is also an excellent one-electron oxidant of iron porphyrin complexes. Such oxidation of Fem(0Cl03)(TPP), where TPP is meso-tetraphenylporphyrin, provides the corresponding porphyrin 7r-cation radical analytically pure [32]. Similar oxidation of the AT-methyl porphyrin complex (N-MeTPP)FenCl, where AT-MeTPP is AT-methyl-meso-tetraphenylporphyrin, afforded [N-MeTPPFemCl]+ which was not further oxidized [33]. Thus thianthrene radical cation selectively oxidized the aromatic porphyrin ligand in one case and the metal center in the other. Ligand oxidation at a phenolic moiety has also been reported [34] on treatment of a 1,4,7-triazacyclononane appended with one or two phenol moieties ligated to Cu(II) complex with thianthrene radical cation. 

Excellent perfomances have been obtained in the reaction of HPNP and of diribonu-cleoside monophosphates with the heterobifunctional catalyst 32H -Cu featuring a triazacyclononane 9[ane]N3 (TACN) and a guanidinium moiety [30]. 

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