Development of Site-Selective C-H Transformations Using Noncovalent Interaction

The control of site-selectivity is important to obtain the desired products efficiently in synthetic organic chemistry. Because there are many C-H bonds with similar reactivities in organic molecules, it was difficult to promote site-selective C-H transformations without using directing groups. In this award article, I describe new strategies to control site-selectivity in C-H transformations using noncovalent interactions, such as hydrogen bond, Lewis acid-base interaction and electrostatic interaction, between the catalyst and the substrate. As a result, highly site-selective C-H transformations have been achieved. By using Lewis acid-base interaction between the substrate and reagent, ortho-selective C(sp2)-H borylation and silylation were achieved. In addition, site-selective C(sp2)-H trifluoromethylation was developed by inclusion of the aromatic substrate into cyclodextrin by supramolecular interaction.