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Updated: Jan 7, 2026

Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
Gold(I)-Catalyzed Synthesis of 1H‑Isochromenes
Julianna M Mouat1, Navraj Singh2, Miles L McCue2
1Southwestern University, Department of Chemistry and Biochemistry, 1001 E. University Ave., Georgetown, Texas 78626, United States.
Abstract:
Belonging to a greater class of biologically active molecules known as benzopyrans, 1H-isochromenes and their isomers are known to exhibit a variety of medically relevant properties. An atom economical synthesis of these valuable organic moieties has been developed utilizing a gold-(I)-catalyzed cyclization of o-alkynylbenzyl alcohols. The desired 1H-isochromenes have been isolated in good yields exclusively yielding the 6-endo-dig product for most substrates. The mechanism of this reaction has been probed providing evidence for a gold-stabilized carbocation intermediate which is responsible for this high degree of regioselectivity.
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