A new ruthenium-catalyzed direct and selective synthesis of semisaturated bicyclic pyrimidines, from α-aminopyridyl alcohols and nitriles, has been demonstrated. The synthesis proceeds with an easily available catalyst system, broad substrate scope, excellent functional tolerance, and no need for high pressure H gas. Control experiments indicate that the reaction proceeds via successive dehydrogenative annulation and transfer hydrogenation of the less electrophilic pyridyl nucleus, and the density functional theory (DFT) study reveals the origin of such a unique selectivity.
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http://dx.doi.org/10.1021/acs.orglett.7b01081 | DOI Listing |
Commun Chem
December 2024
KAUST Catalysis Center, King Abdullah University of Science and Technology (KAUST), Thuwal, 23955-6900, Saudi Arabia.
Synthetic chemistry approaches for direct C-H bond alkylation offers a promising alternative to traditional functional-group-centered strategies which often involve multi-step procedures and may suffer from a variety of challenges including scalability. Here, we introduce resonant mixing as an efficient method for meta-C-H alkylation of arenes using a Ru-catalyst, avoiding the need for bulk solvents, external temperature, or light. The described methodology is highly rapid, enabling multigram-scale synthesis of meta-alkylation products within a short reaction time and achieving a very high turnover frequency.
View Article and Find Full Text PDFOrg Lett
December 2024
Department of Chemistry, Rutgers University, 73 Warren Street, Newark, New Jersey 07102, United States.
Molecular editing of quinazolinones to isoquinolines by a novel ruthenium-catalyzed [4+2] annulation with sulfoxonium ylides has been developed. The method permits the precise and rapid assembly of multisubstituted aminoisoquinolines, a class of heterocycles that play a privileged role in organic synthesis and pharmaceutical development. This new catalytic process exhibits novel programmability, including directed C-H acetylation, nucleophilic cyclization, and alcoholysis.
View Article and Find Full Text PDFChem Commun (Camb)
September 2024
Department of Chemistry, School of Advanced Sciences, Vellore Institute of Technology, Vellore, Tamil Nadu-632014, India.
Herein, we disclose the first reports on the utilization of vinylene carbonate as a C1 methylene source in ruthenium-catalyzed additive controlled regioselective C4-methylenation and weak chelation-assisted C8-formylmethylation of isoquinolinones. Adopting vinylene carbonate as both a C2 and C1 synthon is an important highlight of this work. Amide carbonyl acts as the traceless directing group in C8-formylmethylation.
View Article and Find Full Text PDFChem Asian J
November 2024
Instituto de Ciências Exatas, Departamento de Química, Universidade deral de Minas Gerais, Belo Horizonte, MG, 31270-901, Brazil.
Herein, we describe the Ru-catalyzed C-H alkenylation of 1,4-naphthoquinones (1,4-NQs), resulting in 1,4-naphthoquinoidal/SuFEx hybrids with moderate to good yields. This method provides a novel route for direct access to ethenesulfonyl-fluorinated quinone structures. We conducted mechanistic studies to gain an in-depth understanding of the elementary steps of the reaction.
View Article and Find Full Text PDFNat 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.
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