Copper-Catalyzed Formal Aldehydic C–H Borylation Enabled by an sp<sup>2</sup>–sp<sup>3</sup> Diboron Reagent
Jiaxin Lin, Peiqi Zhang, Xiangyu Lou, Zhenyang Lin, Hairong Lyu, Yangjian Quan
Abstract
We have developed a copper-catalyzed formal aldehydic C–H borylation using a neutral sp 2 –sp 3 diboron reagent, LBH 2 –Bpin (where L is a σ-donor), leading to the one-pot synthesis of diverse acylboranes. Notably, the BH moieties in the acylborane can be further used to construct boracycles. This protocol enables straightforward functional group (FG) replacement of commercial medicines with an acylboron motif. Detailed mechanistic studies and DFT calculations reveal a synergistic hydride transfer pathway, which is promoted by the electron-rich nature of the LBH 2 fragment. This investigation highlights the potential of the new diboron reagent in accessing reaction modes that were previously unachievable.