Palladium-Catalyzed Weakly Coordinating Lactone-Directed C–H Bond Functionalization of 3-Arylcoumarins: Synthesis of Bioactive Coumestan Derivatives

Transition metal-catalyzed selective C–H bond functionalization enabled by transient ligands has become an extremely attractive topic due to its economical and greener characteristics. However, catalytic pathways of this reaction process on unactivated sp3 carbons of reactants have not been well studied yet. Herein, detailed mechanistic investigation on Pd-catalyzed C(sp3)–H bond activation with amino acids as transient ligands has been systematically conducted. The theoretical calculations showed that higher angle distortion of C(sp2)-H bond over C(sp3)-H bond and stronger nucleophilicity of benzylic anion over its aromatic counterpart, leading to higher reactivity of corresponding C(sp3)–H bonds; the angle strain of the directing rings of key intermediates determines the site-selectivity of aliphatic ketone substrates; replacement of glycine with β-alanine as the transient ligand can decrease the angle tension of the directing rings. Synthetic experiments have confirmed that β-alanine is indeed a more efficient transient ligand for arylation of β-secondary carbons of linear aliphatic ketones than its glycine counterpart.

Download Full-text

Palladium-Catalyzed Asymmetric Synthesis of Silicon-Stereogenic Dibenzosiloles via Enantioselective C–H Bond Functionalization

Journal of the American Chemical Society ◽

10.1021/ja302278s ◽

2012 ◽

Vol 134 (17) ◽

pp. 7305-7308 ◽

Cited By ~ 158

Author(s):

Ryo Shintani ◽

Haruka Otomo ◽

Kensuke Ota ◽

Tamio Hayashi

Keyword(s):

Asymmetric Synthesis ◽

Bond Functionalization ◽

Palladium Catalyzed

Download Full-text

ChemInform Abstract: Regiocontrolled Palladium-Catalyzed and Copper-Mediated C-H Bond Functionalization of Protected L-Histidine.

ChemInform ◽

10.1002/chin.201444213 ◽

2014 ◽

Vol 45 (44) ◽

pp. no-no

Author(s):

Amit Mahindra ◽

Rahul Jain

Keyword(s):

Bond Functionalization ◽

Palladium Catalyzed

Download Full-text

Palladium-catalyzed allylic C–H oxidation under simple operation and mild conditions

Organic & Biomolecular Chemistry ◽

10.1039/c9ob00209j ◽

2019 ◽

Vol 17 (12) ◽

pp. 3103-3107 ◽

Cited By ~ 1

Author(s):

Yunlong Guo ◽

Zengming Shen

Keyword(s):

Simple System ◽

Allylic Alcohols ◽

Bond Functionalization ◽

Simple Operation ◽

Mild Conditions ◽

Palladium Catalyzed

We discovered an effective and simple system (Pd/BQ/air/r.t.) for making allylic alcohols through Pd-catalyzed allylic C–H bond functionalization.

Download Full-text

Recent Advances in Palladium-Catalyzed Bridging C–H Activation by Using Alkenes, Alkynes or Diazo Compounds as Bridging Reagents

Synthesis ◽

10.1055/s-0040-1707268 ◽

2020 ◽

Vol 53 (02) ◽

pp. 238-254

Author(s):

Fulin Zhang ◽

Luoting Xin ◽

Saihu Liao ◽

Xueliang Huang ◽

Yinghua Yu

Keyword(s):

Bond Distance ◽

Short Review ◽

Diazo Compounds ◽

Bond Functionalization ◽

Migratory Insertion ◽

Intramolecular Reactions ◽

Palladium Catalyzed ◽

Direct Functionalization ◽

Intermolecular Reactions ◽

Metal Catalyzed

AbstractTransition-metal-catalyzed direct inert C–H bond functionalization has attracted much attention over the past decades. However, because of the high strain energy of the suspected palladacycle generated via C–H bond palladation, direct functionalization of a C–H bond less than a three-bond distance from a catalyst center is highly challenging. In this short review, we summarize the advances on palladium-catalyzed bridging C–H activation, in which an inert proximal C–H bond palladation is promoted by the elementary step of migratory insertion of an alkene, an alkyne or a metal carbene intermediate.1 Introduction2 Palladium-Catalyzed Alkene Bridging C–H Activation2.1 Intramolecular Reactions2.2 Intermolecular Reactions3 Palladium-Catalyzed Alkyne Bridging C–H Activation3.1 Intermolecular Reactions3.2 Intramolecular Reactions4 Palladium-Catalyzed Carbene Bridging C–H Activation5 Conclusion and Outlook

Download Full-text