This paper reports the first example of C-H arylation of benzene under mild conditions, using H as an electron source {turnover numbers (TONs)=0.7-2.0 for 24 h}. The reaction depends on a Rh-based electron storage catalyst, and proceeds at room temperature and in aqueous solution. Furthermore, the H is inactive during the radical transfer step, greatly reducing unwanted side reactions.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1002/chem.202102735 | DOI Listing |
J Am Chem Soc
January 2025
Department of Chemistry, University of Houston, Houston, Texas 77204-5003, United States.
Monoanionic, bidentate-auxiliary-directed, cobalt-catalyzed C-H bond functionalization has become a very useful tool in organic synthesis. A comprehensive investigation into isolated organometallic intermediates and their reactivity within the catalytic cycle is lacking. We report here mechanistic studies of cobalt-catalyzed, aminoquinoline-directed C(sp)-H bond functionalization.
View Article and Find Full Text PDFOrg Lett
January 2025
School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Suruga-ku, Shizuoka 422-8526, Japan.
The C2- or C3-selective direct C-H arylation of nonsubstituted 1-pyrrole with aryl chlorides/nonaflates was achieved using catalysts derived from palladium and appropriate phosphine ligands. The site selectivity of the arylation can be switched by changing the ligands, and the C3-selective arylation of nonsubstituted 1-pyrrole was realized for the first time. BuOLi played an important role in suppressing N-arylation and accelerating C2- or C3-arylation.
View Article and Find Full Text PDFCatal Sci Technol
December 2024
Department of Chemistry, Biochemistry and Pharmaceutical Sciences, University of Bern Freiestrasse 3 3012 Bern Switzerland
Even though α-arylation of ketones is attractive for direct C-H functionalization of organic substrates, the method largely relies on phosphine-ligated palladium complexes. Only recently, efforts have focused on developing nitrogen-based ligands as a more sustainable alternative to phosphines, with pyridine-functionalized pyridinium amidate (pyr-PYA) ,'-bidentate ligands displaying good selectivity and activity. Here, we report on a second generation set of catalyst precursors that feature a 5-membered N-heterocycle instead of a pyridine as chelating unit of the PYA ligand to provide less steric congestion for the rate-limiting transmetalation of the enolate.
View Article and Find Full Text PDFNature
January 2025
Department of Chemistry, The Scripps Research Institute, La Jolla, CA, USA.
C-H activation is the most direct way of functionalizing organic molecules. Many advances in this field still require specific directing groups to achieve the necessary activity and selectivity. Developing C-H activation reactions directed by native functional groups is essential for their broad application in synthesis.
View Article and Find Full Text PDFOrg Lett
January 2025
School of Chemistry and Materials Science, Jiangsu Key Laboratory of Green Synthesis for Functional Materials, Jiangsu Normal University, Xuzhou, Jiangsu 221116, China.
Herein, we present a Pd(OAc)/Dppp-catalyzed synthesis of 4-arylphenanthridinones from 2-bromobenzamides and iodobenzene, which undergoes successive Ullman cross-coupling, C-H activation, and oxidative coupling dehydrogenation process. The presented methods offer an adaptable and modular synthesis route for efficiently producing a wide array of valuable phenanthridiones, demonstrating exceptional compatibility with functional groups. Alternatively, a 1:1 cross-coupling reaction utilizing an intramolecular norbornene moiety as the ligand resulted in phenanthridinones through -arylation and C-H activation.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!