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Gold(I)‐Catalyzed Haloalkynylation of Aryl Alkynes: Two Pathways, One Goal
Author(s) -
Kreuzahler Mathis,
Haberhauer Gebhard
Publication year - 2020
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201916027
Subject(s) - chemistry , enyne , catalysis , aryl , halogen , conjugated system , combinatorial chemistry , atom (system on chip) , computational chemistry , medicinal chemistry , organic chemistry , alkyl , polymer , computer science , embedded system
Haloalkynylation reactions provide an efficient method for the simultaneous introduction of a halogen atom and an acetylenic unit. For the first time, we report a gold(I)‐catalyzed haloalkynylation of aryl alkynes that delivers exclusively the cis addition product. This method enables the simple synthesis of conjugated and halogenated enynes in yields of up to 90 %. Notably, quantum chemical calculations reveal an exceptional interplay between the place of the attack at the chloroacetylene: No matter which C−C bond is formed, the same enyne product is always formed. This is only possible through rearrangement of the corresponding skeleton. Hereby, one reaction pathway proceeds via a chloronium ion with a subsequent aryl shift; in the second case the corresponding vinyl cation is stabilized by a 1,3‐chlorine shift. 13 C‐labeling experiments confirmed that the reaction proceeds through both reaction pathways.