Distal γ‐C(sp<sup>3</sup>)−H Olefination of Ketone Derivatives and Free Carboxylic Acids
Han Seul Park, Zhoulong Fan, Ru‐Yi Zhu, Jin‐Quan Yu
Abstract
Abstract Reported herein is the distal γ‐C(sp 3 )−H olefination of ketone derivatives and free carboxylic acids. Fine tuning of a previously reported imino‐acid directing group and using the ligand combination of a mono‐N‐protected amino acid (MPAA) and an electron‐deficient 2‐pyridone were critical for the γ‐C(sp 3 )−H olefination of ketone substrates. In addition, MPAAs enabled the γ‐C(sp 3 )−H olefination of free carboxylic acids to form diverse six‐membered lactones. Besides alkyl carboxylic acids, benzylic C(sp 3 )−H bonds also could be functionalized to form 3,4‐dihydroisocoumarin structures in a single step from 2‐methyl benzoic acid derivatives. The utility of these protocols was demonstrated in large scale reactions and diversification of the γ‐C(sp 3 )−H olefinated products.