Copper-Catalyzed Hydrogen/Iodine Exchange in Terminal and 1-Iodoalkynes

Abstract

Detailed kinetic profiles of the copper-catalyzed exchange between the acetylenic proton and iodide of terminal and 1-iodophenylacetylenes are reported. The electronic nature of the alkynes does not influence the equilibrium of the exchange (K eq = 1), only the rate of equilibration. Notably, the profiles are the same for electron-rich, methyl-substituted phenylacetylenes but are divergent for electron-deficient, trifluoromethyl-substituted variants. The heretofore unreported exchange process yields practical considerations regarding reactions involving iodo and terminal alkynes.

Catalytic Isofunctional Reactions—Expanding the Repertoire of Shuttle and Metathesis Reactions

“…[142] 3.11. Theg roup of Hein chose to pursue the study of the kinetics of this reaction given its relevance to Glaser-Hay and Cadiot-Chodkiewicz coupling reactions.…”

“…A related Cu‐catalyzed C−halogen/C−H metathesis reaction of alkynes has also been developed. The group of Hein chose to pursue the study of the kinetics of this reaction given its relevance to Glaser–Hay and Cadiot–Chodkiewicz coupling reactions …”

Katalytische, isofunktionelle Reaktionen – Erweiterung des Repertoires an Shuttle‐ und Metathesereaktionen

“…[142] 3.11. Die Gruppe von Hein entschied sich, wegen der Relevanz dieser Reaktion fürG laser-Hay-und Cadiot-Chodkiewicz-Kupplungen eine kinetische Studie durchzuführen.…”

“…Die Gruppe von Hein entschied sich, wegen der Relevanz dieser Reaktion fürG laser-Hay-und Cadiot-Chodkiewicz-Kupplungen eine kinetische Studie durchzuführen. [142] 3.11. C-C-Metathesereaktionen Das Durchführen von Reaktionen unter Spaltung von C-C-Bindungen ist noch immer anspruchsvoll, vor allem im Falle von unpolarisierten C-C-Bindungen.…”

Regio‐ and Stereoselective Synthesis of Enynyl‐Aryl Ethers Enabled by Copper/Iodide Tandem Catalysis

“…First, the transformation is initiated by the reaction of an iodide source (TBAI or CuI) and PhI(OAc) 2 to generate IOAc, [20] which works as a strong electrophile against alkyne 2 a to give (iodoethynyl)benzene 7 in the company of a hydrogen/iodine exchange equilibrium process. [21] Then intermolecular nucleophilic addition of phenol 1 a to 7 assisted by base delivers 8 with excellent regio-and stereoselectivity. [2f] Subsequently, 8 rapidly reacts with 6 which is mainly produced by the reaction of 7 and CuI [16] to form a Cu III intermediate I via oxidative addition, and then intermediate I undergoes reductive elimination to give (Z)-3 aa and release CuI, [7d,e] which can regenerate IOAc assisted by PhI(OAc) 2.…”