Balancing Reactivity, Regioselectivity, and Product Stability in Ir-Catalyzed Ortho-C−H Borylations of Anilines by Modulating the Diboron Partner

Abstract

Ir-catalyzed arene C−H borylations (CHB) of anilines can be highly ortho selective by using a small B2eg2 (eg = ethane-1,2-diol) as the borylating reagent. Unfortunately, the products are prone to decomposition, and transesterification with pinacol is required prior to isolation. This work offers a solution by adjusting the size of the diboron reagent. Based on our evaluation, we conclude that B2bg2 (bg = butane-1,2-diol) achieves an optimal balance between CHB regioselectivity and stability for the borylated products.