OH‐Directed Alkynylation of 2‐Vinylphenols with Ethynyl Benziodoxolones: A Fast Access to Terminal 1,3‐Enynes |
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| Authors: | Peter Finkbeiner Ulrich Kloeckner Jun.‐Prof. Dr. Boris J. Nachtsheim |
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| Affiliation: | Institut für Organische Chemie, Eberhard Karls Universit?t Tübingen, Auf der Morgenstelle 18 (Germany) |
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| Abstract: | The first direct alkynylation of 2‐vinylphenols was developed. The rationally optimized hypervalent iodine reagent TIPS‐EBX* in combination with [(Cp*RhCl2)2] as a C? H‐activating transition metal catalyst enables the construction of a variety of highly substituted 1,3‐enynes in high yields of up to 98 %. This novel C? H activation method shows excellent chemoselectivity and exclusive (Z)‐stereoselectivity, and it is also remarkably mild and tolerates a variety of functional groups. Furthermore, synthetic modifications of the resulting 1,3‐enynes were demonstrated. To our knowledge, this is the first example for an OH‐directed C? H alkynylation with hypervalent iodine reagents. |
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| Keywords: | alkynes C H activation enynes iodine rhodium |
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