Transition-Metal-Free Difunctionalization of Sulfur Nucleophiles** |
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Authors: | Dr. Shobhan Mondal Ester Maria Di Tommaso Prof. Berit Olofsson |
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Affiliation: | Department of Organic Chemistry, Arrhenius Laboratory, Stockholm University, 10691 Stockholm, Sweden |
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Abstract: | Efficient protocols for accessing iodo-substituted diaryl and aryl(vinyl) sulfides have been developed using iodonium salts as reactive electrophilic arylation and vinylation reagents. The reactions take place under transition-metal-free conditions, employing odorless and convenient sulfur reagents. A wide variety of functional groups are tolerated in the S-diarylation, enabling the regioselective late-stage application of several heterocycles and drug molecules under mild reaction conditions. A novel S-difunctionalization pathway was discovered using vinyliodonium salts, which proceeds under additive-free reaction conditions and grants excellent stereoselectivity in the synthesis of aryl(vinyl) sulfides. A one-pot strategy combining transition-metal-free diarylation and subsequent reduction provided facile access to electron-rich thioanilines and a direct synthesis of a potential drug candidate derivative. The retained iodo group allows a wide array of further synthetic transformations. Mechanistic insights were elucidated by isolating the key intermediate, and the relevant energy profile was substantiated by DFT calculations. |
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Keywords: | Aromatic Substitution Difunctionalization Hypervalent Compounds Iodonium Salts Sulfides |
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