Organocopper triggered cyclization of conjugated dienynesviatandem S_N2′/Alder-ene reaction

Abstract

Propargylic carbonates were converted to indenes through a SN2′/Alder-ene cascade triggered by organocopper reagents.

Efficient Heterogeneous Copper-Catalyzed Alder-Ene Reaction of Allenynamides to Pyrrolines

“…The Alder-ene reaction has been recognized as a powerful synthetic tool for the rapid construction of C–C bonds with high atom economy and efficiency . Since the seminal work by Trost on the palladium-catalyzed intramolecular ene reactions of 1,6-enynes, the ene-type cycloisomerizations of various 1, n -unsaturated systems, such as dienes, enynes, triynes, and enallenes, have been reported. However, the corresponding Alder-ene reaction of allenynes is less investigated. , In 2002, Brummond reported the rhodium­(I)-catalyzed formal Alder-ene-type reaction of 1,6-allenynes for stereoselective synthesis of cross-conjugated trienes (Scheme a) .…”