An Enantioselective Iodolactonization/Cross‐Coupling Protocol for the Synthesis of Highly Substituted Enol Lactones
γ‐Alkynoic acids readily undergo iodolactonization to give iodoenol lactones. Using commercially available (DHQD)2PHAL this transformation can be rendered asymmetric. In desymmetrization reactions of dialkynoic acids, good to very good enantioselectivities can be observed. Alternatively, kinetic res...
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Veröffentlicht in: | European journal of organic chemistry 2018-06, Vol.2018 (24), p.3158-3166 |
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Sprache: | eng |
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Zusammenfassung: | γ‐Alkynoic acids readily undergo iodolactonization to give iodoenol lactones. Using commercially available (DHQD)2PHAL this transformation can be rendered asymmetric. In desymmetrization reactions of dialkynoic acids, good to very good enantioselectivities can be observed. Alternatively, kinetic resolution of already chiral, racemic γ‐alkynoic acids can be carried out. The products of these iodolactonizations, iodoenol lactones, are suitable substrates for Palladium catalyzed cross‐couplings. Negishi‐ as well as Sonogashira couplings can be carried out and allow the efficient synthesis of highly substituted enol lactones.
A sequence of catalytic enantioselective iodolactonization followed by Palladium‐catalyzed cross‐coupling provides rapid access to highly substituted enol lactones. With DHQD2PHAL as catalyst, moderate to very good enantioselectivities in the iodolactonization step can be obtained. |
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ISSN: | 1434-193X 1099-0690 |
DOI: | 10.1002/ejoc.201800642 |