Pd<sup>II</sup>–Catalyzed Site-selective β- and γ-C(sp<sup>3</sup>)–H Arylation of Primary Aldehydes Controlled by Transient Directing Groups
作者:Yi-Hao Li、Yuxin Ouyang、Nikita Chekshin、Jin-Quan Yu
DOI:10.1021/jacs.1c13586
日期:2022.3.23
Pd(II)-catalyzed site-selective β- and γ-C(sp3)–H arylation of primary aldehydes is developed by rational design of L,X-type transient directing groups (TDG). External 2-pyridone ligands are identified to be crucial for the observed reactivity. By minimizing the loading of acid additives, the ligand effect is enhanced to achieve high reactivities of the challenging primary aldehyde substrates. Site
Pd(II) 催化的位点选择性 β- 和 γ-C(sp 3 )–H 伯醛芳基化是通过 L,X 型瞬态导向基团 (TDG) 的合理设计开发的。外部 2-吡啶酮配体被确定为对观察到的反应性至关重要。通过最大限度地减少酸添加剂的负载,配体效应得到增强,以实现具有挑战性的伯醛底物的高反应性。通过改变 TDG 的咬角以匹配所需的 palladacycle 大小,可以将位点选择性从最近位置切换到相对较远的位置。实验和计算研究支持设计 TDG 以潜在实现远程位点选择性 C(sp 3 )–H 功能化的基本原理。