Recent advances in catalytic C−H borylation reactions

In the past decades, the iridium-catalyzed C–H bond borylation and other newly discovered catalytic borylation reactions have received extensive research interests and developed into a practical approach for functionalization of C−H bonds and therefore an effective and versatile tool in synthesis of novel organic materials, natural products and fine chemicals. The advances of this booming field include significant improvements of the venerable iridium-catalyzed borylation and development of other transition-metal, especially the first-row transition-metal catalyzed borylation. More recently, a metal-free catalytic borylation system has been disclosed. These new methodologies has dramatically expanded the substate scope, increased the reaction efficiency, lowered the cost, and more importantly, provided previously unknown complementary chemical and regioselectivity. During these discoveries, novel catalyst design concepts and/or principles have been generated. In this context, this review aims to detail the recent evolution in the exciting research direction, focusing on the discovery and development of new reactivity, new selectivity.