Based Linear Assemblies

Assemblies relying on the dative B-N interaction in conjunction with boronate ester formation to form linear polymers have also been identified. Unlike the stepwise phenanthroline-boronate assembly, esterification coupled with ligation occurs simultaneously. In fact, it is likely that coordination 

FIGURE 11. The synthesis of dendrimers based on a coordinatively assembled pyridine-boronate ester macrocyles combine ester formation, B-N interaction, and imine formation in one step. 

FIGURE 12. Coordinative linear polymers based on boronate ester formation result from (a) ditopic coordination of pyridyl boronic acids to bis-diol functionalized porphyrins and (b) through coordinative interactions between rhodoximes and 3-aminoboronic acid. 

FIGURE 13. Di-boronate esters based on 1,2,4,5-tetrahydroxybenzene coodinatively interact with bipyridyl systems to form zigzag linear polymers (Reprinted with permission from Ref. 38. Copyright 2007 Wiley-VCH Verlag GmbH Co. KGaA.) 

FIGURE 14. Boronate ester formation produces poly(adenosme) RNA mimics that coordinate with poly(uracil) to produce organized duplex RNA motifs. 

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Many of the polycyclic antibiotics are based on linear assemblies of three or more six-membered rings, such as the tetracycline and anthracycline antibiotics (examples are chlortetracycline and... 

Fig. 7 Synthesis of pyridinium-based cationic lipids by a linear assembly strategy...

Ding and coworkers replaced the terpyridine moieties with a chiral Eeringa s MonoPhos ligand to obtain a UPy-based bifunctional monomer 18 [38]. With the addition of [Rh(cod)2]Bp4 to the solution of 18 in CH2CI2, it could form a linear-assembled polymer with alternative orthogonal P-Rh coordination and UPy dimerization in the main chain (Scheme 10.5). The supramolecular coordination polymer 19 was insoluble in the apolar solvent such as toluene, which assured facile recovery and reusability of this catalyst. More importantly, this kind of heterogeneous catalyst showed excellent reactivity and enantioselectivity in the hydrogenation reaction. 

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