Macrocycles binaphthyl-based chiral

Figure 9.8) [70]. This work is part of a broader activity in the field of binaphthyl-based chiral macrocycles for chiroptical sensing and chiral nanostructuring [71-87]. The macrocycle 23 incorporates a Binol unit. In order to counterbalance the inherent distortion brought about by the binaphthyl units into the macro-cyclic framework, sp carbon atoms, imparting a higher conformational freedom with respect to sp- or sp -hybridized carbon atoms, have been introduced. 

Binaphthyl based structures are not the only chiral groups that have been incorporated into the backbone of chiral macrocydes. Recently, there has been an increasing number of reports of macrocydes that are chiral due to the incorporation of a helicene moiety [62]. One of the earhest stmctures to be reported was from Wennerstrom and coworkers [63] and linked directly two [5]hehcenes to give macrocycle 169, which came to be known as propdhcene. 

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