Catalytic C-H Arylation of Aliphatic Aldehydes Enabled by a Transient Ligand

The direct arylation of aliphatic aldehydes has been established via Pd-catalyzed sp³ C-H bond functionalization in the presence of 3-aminopropanoic acids as transient directing groups. The reaction showed excellent functional group compatibility and chemoselectivity in which a predominant preference for functionalizing unactivated β-C-H bonds of methyl groups over others was achieved. In addition, C-H bonds of unactivated secondary sp³ carbons can also be functionalized. The extreme popularity and importance of aliphatic aldehydes would result in broad applications of this novel method in organic chemistry and medicinal sciences.