Recent progress of transition metal-catalysed regioselective C-H transformations based on noncovalent interactions.

Transition metal-catalysed C-H transformations are powerful methods to obtain functionalised organic molecules from simple starting materials. Controlling regioselectivity is one of the most important issues in C-H transformations. Since the remarkable work by Murai and co-workers in 1993, many groups have reported ortho-selective C(sp2)-H transformations using directing group methods, in which interactions exist between substrates and catalytically active metal centres. In this review, new methodologies to achieve regioselective C-H transformations are described. In these methhodologies, noncovalent interactions between substrates and reagents or ligands of catalysts play important roles. In these cases, selective functionalization of remote C-H bonds, such as meta- and para-C-H bonds, can also be realized.