Magic rings

The Magic Ring of Francis Bacon. Pittsburgh (self-published), 1930. 

Samantha s mother rushed to her side. Samantha was right. She was holding a part of her tooth in her hand along with the free magic ring she had been searching for. 

Figure 7 Organic Magic rings . Interconversion between macrocycle and catenane under thermodynamic control...

The metal coordination strategy of Fujita has been used to design a [2]catenane whose behavior is remarkably like that of magic rings able to... 

Catenane Formation from Preformed Rings Molecular Magic Rings. . 12... 

Catenanes have attracted considerable current interest particularly owing to their recently explored potential as molecular-scale devices. The incorporation of a coordination bond into catenane frameworks makes it possible to realize a quick molecular motion, which is somewhat similar to that of well-known magic rings under thermodynamic conditions a catenane framework rapidly arises from two preformed molecular rings. In the following sections, we describe the self-assembly, chemical manipulation, and characterization of several self-assembled catenanes. 

Figure 25 (a) Synthesis of mixed benzylic amide esto catenane 93 by template-directed synthesis and (b) magic-ring catenane 95... 

Figure 1 Catenanes (a) nomenclature [w+2]catenane and (b) general synthetic strategies to obtain a [2]catenane (i) clipping (ii) double clipping , and (iii) magic ring synthesis .

Magic ring synthesis of catenanes with metal cations in the macrocycle backbone... 

Figure 11 Magic ring synthesis of Fujita s Pd(II) pyridyl...

Figure 12 Magic ring syntheses of Beer s Cu(II)/Cn(III) and Cn(II)/An(III) dithiocarbamate [2]catenanes.

Figure 16 Protonated ammonium temptation (a) magic ring synthesis of Stoddart s [2]catenane and (b) porphyrin-containing [2]catenane.

Magic ring synthesis A method for synthesizing interlocked structures where preformed component(s) (e.g., a macrocycle) reversibly open and close to form the interlocked structure. 

New catenanes are now produced by interaction of a macrocycle containing an ammonium salt 37 with either the macrocycle precursor 33 or the macrocycle 34 in the presence of catalyst 3 (Scheme 18) [47]. Thus, the catenane 38 was produced in good yield. In order to avoid the process reversibility, the hydrogenation of 38 (PtOi) affords the stable catenane 39. The direct transformation of two macrocycles 34 and 37 into the interlocked macrocycle molecule 38 illustrates magic rings interlocking [47]. 

Guidry, E.N., Cantrill, S.J., Stoddart, J.F., and Grubbs, R.H. (2005) Magic ring catenation by olefin metathesis. Organic Letters, 7,2129-2132. 

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