A Ru-catalyzed direct CH activation/meta-bromination of arenes bearing pyridyl, pyrimidyl, and pyrazolyl directing groups has been developed. A series of bromo aryl pyridines and pyrimidines have been synthesized, and further coupling reactions have also been demonstrated for a number of representative functionalized arenes. Preliminary mechanistic studies have revealed that this reaction may proceed through radical-mediated bromination when NBS is utilized as the bromine source. This type of transformation has opened up a new direction for the radical non-ipso functionalization of metal with regard to future CH activation development that would allow the remote functionalization of aromatic systems.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1002/anie.201507100 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Noncovalent Interactions in Palladium(II)-Catalyzed Meta-Selective C-H Functionalization: Mechanistic Insights and Origins of Regioselectivity.
Chemphyschem
December 2024
Departament of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, Av. Prof. Lineu Prestes, 748, São Paulo, 05508-000, Brazil.
The use of noncovalent interactions to control the regioselectivity of transition metal-catalyzed C-H functionalization of arenes has received significant attention in recent years. Herein, we present a mechanistic study based on Density Functional Theory (DFT) of palladium(II)-catalyzed meta-selective C-H olefination employing a noncovalent directing template. We analyze the key steps of the mechanism and discuss the origins of reaction selectivity.
View Article and Find Full Text PDFLeveraging long-lived arenium ions in superacid for meta-selective methylation.
Nat Commun
August 2024
Université de Poitiers, CNRS, Institut de Chimie des Milieux et Matériaux de Poitiers (IC2MP), 86073, Poitiers, Cedex 9, France.
Electrophilic aromatic substitution is one of the most mechanistically studied reactions in organic chemistry. However, precluded by innate substituent effects, the access to certain substitution patterns remains elusive. While selective C-H alkylation of biorelevant molecules is eagerly awaited, especially for the insertion of a methyl group whose magic effect can boost lead molecules potency, one of the most obvious strategies would rely on electrophilic aromatic substitution.
View Article and Find Full Text PDFElectrochemical meta-C-H sulfonylation of pyridines with nucleophilic sulfinates.
Nat Commun
August 2024
Guangzhou Municipal and Guangdong Provincial Key Laboratory of Molecular Target & Clinical Pharmacology, the NMPA and State Key Laboratory of Respiratory Disease, School of Pharmaceutical Sciences and the Fifth Affiliated Hospital, Guangzhou Medical University, Guangzhou, Guangdong, PR China.
Considering the indispensable significance and utilities of meta-substituted pyridines in medicinal, chemical as well as materials science, a direct meta-selective C-H functionalization of pyridines is of paramount importance, but such reactions remain limited and highly challenging. In general, established methods for meta C-H functionalization of pyridines rely on the utilization of tailored electrophilic reagents to realize the intrinsic polarity match. Herein, we report a complementary electrochemical methodology; diverse nucleophilic sulfinates allow meta-sulfonylation of pyridines through a redox-neutral dearomatization-rearomatization strategy by a tandem dearomative cycloaddition/hydrogen-evolution electrooxidative C-H sulfonation of the resulting oxazino-pyridines/acid-promoted rearomatization sequence.
View Article and Find Full Text PDFOne-Step Synthesis of Chiral 9,10-Dihydrophenanthrenes via Ligand-Enabled Enantioselective Cascade β,γ-Diarylation of Acids.
Angew Chem Int Ed Engl
October 2024
Department of Chemistry, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
Pd(II)-catalyzed enantioselective C-H activation has emerged as a versatile platform for constructing point, axial, and planar chirality. Herein, we present an unexpected discovery of a Pd-catalyzed enantioselective cascade β,γ-methylene C(sp)-H diarylation of free carboxylic acids using bidentate chiral mono-protected amino thioether ligands (MPAThio), enabling one-step synthesis of a complex chiral 9,10-dihydrophenanthrene scaffolds with high enantioselectivity. In this process, two methylene C(sp)-H bonds and three C(sp)-H bonds were activated, leading to the formation of four C-C bonds and three chiral centers in one pot.
View Article and Find Full Text PDFLigand-enabled ruthenium-catalyzed meta-C-H alkylation of (hetero)aromatic carboxylic acids.
Nat Commun
July 2024
Key Laboratory of Functional Molecular Engineering of Guangdong Province, School of Chemistry and Chemical Engineering, South China University of Technology, 510641, Guangzhou, China.
Carboxylates are ideal directing groups because they are widely available, readily cleavable and excellent linchpins for diverse follow-up reactions. However, their use in meta-selective C-H functionalizations remains a substantial unmet catalytic challenge. Herein, we report the ruthenium-catalyzed meta-C-H alkylation of aromatic carboxylic acids with various functionalized alkyl halides.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!