Transition-Metal-Free Synthesis of Borylated Thiophenes via Formal Thioboration
Hassen Bel Abed, Suzanne A. Blum*
*Department of Chemistry, University of California-Irvine, Irvine, California 92617-2025, United States, Email: blumsuci.edu
H. B. Abed, S. A. Blum, Org. Lett., 2018, 20, 6673-6677.
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In a simple, regiocontrolled, and transition-metal-free approach to access exclusively 3-borylated thiophene derivatives, commercially available B-chlorocatecholborane acts as a carbophilic Lewis acid to activate the alkyne in readily synthesized (Z)-organylthioenyne substrates. A formal thioboration and subsequent sulfur dealkylation provide 3-borylated thiophenes in good yields.
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