Dynamic Libraries From Olefin Metathesis Reaction

2 Dynamic Libraries From Olefin Metathesis Reaction 

As reported in 2014, Di Stefimo et al. exploited the ROMP reaction to generate a DL of linear and cyclic species endowed with endotopic 

The saturation profile obtained for the concentration of the cychc monomer on increasing initial monomer concentration allowed an estimate for EMi of 22 mM, Comparison of the latter value with the entropic contribution EM5 = 70 mM predicted for a 28-membered ring obtainable 

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Fig. 27 Examples of thermodynamically controlled reactions employed in the near-quantitative synthesis of MIMs. (a) Disulfide-exchange reaction permits equilibration between a bis(ammo-nium) disulfide dumbbell and a crown ether macrocycle to yield a mixture of [2]- and [3]rotaxanes quantitatively [194], (b) Olefin metathesis at high concentration on a benzylic amide macrocycle greatly favors the catenated species [196]. (c) Self-correcting imine bonds allow for nearly quantitative selection of a [2]rotaxane from an appropriate dynamic combinatorial library [76], (d) A weak nucleophile (E) equilibrates the components of a donor-acceptor [2]catenane in a dynamic Sn2 reaction [205]...

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