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Updated: Jun 16, 2026

A Microwave-Assisted Direct Heteroarylation of Ketones Using Transition Metal Catalysis
Published on: February 16, 2020
Transition-metal-free formal Sonogashira coupling and alpha-carbonyl arylation reactions
Birgit Prüger1, Gretchen E Hofmeister, Christian Borch Jacobsen
1Center for Catalysis, Department of Chemistry, Aarhus University, 8000 Aarhus C, Denmark.
Abstract:
Transition-metal-free formal Sonogashira coupling and alpha-carbonyl arylation reactions have been developed. These transformations are based on the nucleophilic aromatic substitution (S(N)Ar) of beta-carbonyl sulfones to electron-deficient aryl fluorides, producing a key intermediate that, depending on the reaction conditions, gives the aromatic alkynes or alpha-aryl carbonyl compounds. The development of these reactions is presented and, based on investigations under basic and acidic conditions, mechanisms have been proposed. To develop the formal Sonogashira coupling further, a milder, two-step protocol is also disclosed that expands the reaction concept. The scope of these reactions is demonstrated for the synthesis of Sonogashira and alpha-carbonyl arylated products from a range of electron-deficient aryl fluorides with a variety of functional groups and aryl-, heteroaryl-, alkyl-, and alkoxy-substituted sulfone nucleophiles. These transition-metal-free reactions complement the metal-catalyzed versions in terms of substitution patterns, simplicity, and reaction conditions.
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