Transition-Metal-Catalyzed Arylation of Unactivated C(sp³)—H Bonds Assisted by Bidentate Directing Groups

Abstract

Recently, transition-metal-catalyzed C-H functionalization has attracted tremendous interest as a valuable tool for carbon-carbon and carbon-heteroatom bond formation. However, due to the inertness of C(sp 3)-H bonds and the difficulty to achieving high selectivity among the many chemically similar entities in a given molecule, the selective activation of C(sp 3)-H bonds remains a great challenge. The recent progress in transition-metal-catalyzed arylation of unactivated C(sp 3)-H bonds assisted by bidentate directing groups is reviewed, including the scope of reactions, mechanism and synthetic applications.

Advance of Organosilane in Transition-Metal-Catalyzed C—H Functionalization for C—C Bond Formation

“…在 Scheme 2 所示的机理推测中, 双齿导 向基导向的底物 1a 在和二价钯配位后, 与有机硅试剂 进行转金属化反应得到钯物种 1b, 该钯物种经过 C-H 活化形成了双六元环的钯中间体 1c, 然后通过还原消 除得到交叉偶联的目标产物 2. 研究认为, 双齿导向基 有利于碳氢键活化以及促进氧化加成, 这篇报道为近年 来有关有机硅试剂参与的 C-H 官能团化和大量关于双 齿导向基辅助的烷烃 C(sp 3 )-H 键官能团化的发展提供 了研究方向 [26] .…”

Palladium-catalyzed direct β-arylation of ketones with diaryliodonium salts: a stoichiometric heavy metal-free and user-friendly approach

“…While conventional approaches mainly involve the electrophilic ipso carbon and acidic α-C–H bond of carbonyl compounds, recent advances have moved beyond the intrinsic reactivity allowing functionalization of the unactivated β-C–H bonds. 1 Among all of these β-functionalization methods, arylation reactions have received particular attention due to the prevalence of β-aryl carbonyl moieties in a large collection of bioactive compounds, including drug candidates, anti-oxidants and pesticides ( Fig. 1 ).…”

Divergent Synthesis of Silicon-Containing Peptides via Pd-Catalyzed Post-Assembly γ-C(sp3)–H Silylation

“…We initiated the investigations by choosing L -valine methyl ester 1a (98% ee) as the model substrate directed by PA, a strongly coordinating bidentate auxiliary first introduced by Daugulis. − The monosilylated product 2a was obtained in 16% yield with silver carbonate as oxidant in 1,2-dichloroethane (DCE) at 100 °C (Table , entry 1). We were pleased to find that the addition of BQ dramatically improved the yield (entry 2, 73%, mono/di = 3.1:1).…”