Donor building blocks

MOFs containing nitrogen-donor building blocks were also widely investigated, particularly adenine group which was extensively used due to framework robustness, richness in nitrogen sites, and framework diversity [162]. Song et al. [163] reported the preparation of three new... 

Mono- and polyvalent donor building blocks (nucleopbiles)... 

In Chart 1 are listed the most frequently employed mono-donor building blocks in SPOS such as tertiary amines, phosphines, phosphites, alcohols, boronic acids, stannanes, acetylenes, carboxylates and various organometallic nucleophiles. These building blocks are mostly used for the diversification steps to decorate the previously constructed core structures (see Figures 1.9.1 and 1.9.2) or for the final cleavage reactions. 

In Chart 2 are depicted various poly-valent donor building blocks such as thiols, secondary amines, phosphotyl imines and ylids which serve both the purposes of diversification and cleavage as well as of construction of the central core stmctures. Bidentate nucleophiles such as thioamides, thioureas, ureas, isothioureas, amidines, guanidines, 1,2-dihydroxybenzenes, 2-aminothiophenols and others (see Chart 2) were exclusively employed for the synthesis of the cores as exemplified in Chapter 3 and 4 (the indicated references refer to these examples)... 

As a key step for cyclisation they selected the condensation between bis-donor building-blocks (cf. Chapter 1.9.1, Chart ) of the or/to-aininoaniline type and bis-acceptors building-blocks of the imidate type. 

The D-A recognition motif has been widely used for the construction of supramolecular ensembles from the numerous and outstanding architectures published by the group of Stoddart based on the D-A interactions between dioxyben-zene or dioxynaphthalene and bipyridinium complementary units/ to the extensive utilization of the tetrathiafulva-lene (TTF) as r-electron donor building block/ or the incorporation of the PDI unit as w-electron acceptor unit in supramolecular systems. However, D-A tt-interactions have not been explored in Pc systems until very recently. 

In a study of the relative reactivity of glucuronic acid esters thiodonors, the same authors explored the use of monomeric and dimeric donor building blocks in the synthesis of Steptococcus pneumomiae type 3 oligosaccharide in the presence of activator system NIS/TfOH, as for the synthesis of compound 37 see Scheme 9. ... 

Fluorous silyl ethers have also been developed to serve as protecting groups for carbohydrates. A light fluorous silicon group (2, Scheme 8.1) was wielded for the protection of a donor building block, and a trisaccharide was synthesized... 

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