Thread methodology

Scheme 13 Templated synthesis of rotaxane 22 employing the threading-followed-by-capping methodology...

Scheme 15 Templated synthesis of rotaxane 24 employing the threading-followed-by-capping methodology. The shift of the proton from the terminal amine to the secondary amine allows for the threading to occur yielding the pseudorotaxane 26... 

The rotaxanes presented so far in this section have been prepared by the thread-ing-followed-by-capping methodology. However, hydrogen bond-donor templates... 

The common thread in these water deterioration processes is their being cases of intermixing of natural waters of different qualities or mixing of uncontaminated water with contaminated effluents. Hence the need (1) to be familiar with the methodology of mixing identification and reconstruction of the properties of the involved end members (section 6.7) and (2) the establishment of initial databases (section 18.3). 

The early syntheses of catenanes and rotaxanes were mainly based on statistical threading approaches or on directed methodologies involving chemical conversion [30]. To obtain a catenated molecule, one ring must be closed in the presence of a... 

The threading and slippage methodologies were particularly useful for the preparation of the higher order [3]- and [4]-rotaxanes. For example, in the latter case, the reaction produced a mixture of [4]-rotaxane, three-station [3]-rotaxane, and three-station [2]-rotaxane [61]. The yields of the various rotaxanes could be fortunately controlled by the molar ratios of the reactants. 

A very simple way of stoppering a bisammonium thread by using NaBPhi was proposed by Lawrence and Rao. [8a] They managed to obtain a threaded molecular loop - the per-2,6-dimethyl-j5-CD [2]rotaxane 7 - in an excellent 71 % yield by doing the self-assembly in aqueous solution (Fig. 2). Furthermore, the same methodology has been employed successfully [8b] for the construction of the [3]rotaxane 8 incorporating a tetraarylporphyrin unit. 

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