Undirected ortho-selectivity in C–H borylation of arenes catalyzed by NHC platinum(0) complexes

Borylation of arenes with bis(pinacolato)diboron catalyzed by sterically encumbered NHC platinum complexes proceeds predominantly at ortho -position even in the absence of a directing group ( o : m : p ratio up to 10: 3: 1). The similar borylation with pinacolborane would proceed less selectively.