4 - -2,2 :6 ,2"terpyridine ligand, synthesis

For instance, some time ago Newkome et al. reported the synthesis of ruthenium based dendrimers [170]. A dendrimer (80) with twelve peripheral terpyridine ligands was built around a central quaternary carbon-based core. In the final step complexation between the terminal ligand of the dendrimer and a terpyridinyl ruthenium chloride building block afforded the dodecaruthenium cascade molecule 80 (Fig. 35). Thus, preconstructed cores and dendritic fragments were linked by Ru2+ as the connecting unit and this mode of connectivity could be denoted by [—(Ru)—]. 

A general strategy developed for the synthesis of supramolecular block copolymers involves the preparation of macromolecular chains end-capped with a 2,2 6/,2//-terpyridine ligand which can be selectively complexed with RUCI3. Under these conditions only the mono-complex between the ter-pyridine group and Ru(III) is formed. Subsequent reaction with another 2,2 6/,2"-terpyridine terminated polymer under reductive conditions for the transformation of Ru(III) to Ru(II) leads to the formation of supramolecular block copolymers. Using this methodology the copolymer with PEO and PS blocks was prepared (Scheme 42) [ 107]. 

The synthesis of fused terpyridine ligands was recently described (35). The oligo-tridentate ligands 1 - 2 based on alternating pyridines and pyrimidines were obtained by Stille type carbon-carbon bond forming reactions using organotin intermediates. 

Complexes of iminopyridines tend to enter into oxidative addition reactions. Equation (30) (R = H, Me X = Cl, Br) (04EJ12053). An interesting application of the copper(II) complex of N-(2-pyridylmethyl)-pyridine-2-methylketimine is the synthesis of the 4 -(2-pyridyl)-2,2 6, 2"-terpyridine ligand using the reaction sequence illustrated by... 

The preparation of substituted terpyridine frameworks is well documented. Typical substitution patterns focus on functionahzation at the 4 -positions [26, 27]. Here, we will focus on preparations of terpyridines specifically modified at the 6- and 6 -positions, because substituents at these positions are positionally disposed to interact with metal-bound substrates. For clarity, this section will be limited to discussions of two common strategies for the synthesis of appended terpyridine ligands, namely early and late-stage ring assembly approaches. 

Figure 14 Synthesis of tritopic terpyridine ligands 52—54 using the Sonogashira coupling and their self-assembly into cage structures 55—57 under thermodynamic control with IVl = Zn". Energy minimized structures and dimensions and 2D DOSY NMR spectra of 55 (left), 56 (middle), and 57 (right). Adapted with permission from Ref. 14JA10499. Copyright 2014 American Chemical Society.

Phenylmethylsilanediol, synthesis, 42 155 Phenylsilanetriol, monosodium salts, 42 169 4 -Phenyl-2,2 6, 2 -terpyridine bis nickel complex, 30 74 molecular structure, 30 74 PhjtfluorenyllSiOH, 42 197 (Ph(Me2N)C-=Nli], 37 59-65 orientation of imino ligand, 37 61-63 (PhMe SiljCSiH OH, 42 244-245, 248 (PhMe SiljCsiMeHlOH), 42 191 Phosphaalkenes acyclic, 33 338-353 butadienes, 33 346-349 cumulenes, 33 352... 

It has been found that the use, as ligands, of electron-poor phosphines, such as 1,1 -bis(diphenylphosphino)ferrocene, enhances yields ill the palladium-catalysed reaction of aiyl bromides with sodium phenoxides to yield diaryl ethers.87 Palladium-catalysed coupling of ethynylated derivatives of bipyridine or terpyridine with the corresponding bipyridine or terpyridine hahdes or triflates has been used in the synthesis of preorganized polytopic ligands.88... 

Maskus and Abruna [17] functionalized terpyridine (tpy) ligands with thiol groups. These ligands can be employed for Co2+-bridged molecular wires. The synthesis proceeds according to Scheme 10.19. After deprotonation, 59 was alky-... 

Besides metallocycles, metallodendrimers, and metallo-supramolecular polymers [58], few examples of hollow supramolecular architectures have been obtained from polytopic ligands containing terpyridine units. Lehn et al. used heteroaromatic ligands with terpyridine type coordination sites to obtain cylindrical self-assembled architectures (Fig. 11) [60]. For synthesis of the cage 37, tris-2,4,6-(2-pyrimidyl)-l,3,5-triazine (35) was mixed with lead triflate in... 

An efficient synthesis of l-aryl-4,6-diamino-l,2-dihydro-l,3,5-triazines from an acid-catalyzed reaction between the corresponding arylbiguanidine and carbonyl compounds has been reported <02SC2089>. A new family of functionalized terpyridine-like ligands containing a central 1,3,5-triazine, (8a) and (8b) has been synthesized. These compounds exhibit room-temperature luminiscence as their Ru(II) complexes (9a), (9b) and (9c) <02CC1356>. 

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