Copper(i)-catalyzed synthesis of 1,3-enynes via coupling between vinyl halides and alkynes or domino coupling of vinyl halides

Abstract

1,3-Enynes were easily prepared from coupling between vinyl halides and alkynes or domino coupling of vinyl halides in the presence of copper iodide. It is noteworthy that the double-bond geometry of the vinyl halides was retained during the reaction. This ligand-free protocol is potentially useful and practical.

Ring Opening of π-Delocalized 2,5-Diphenyltellurophene by Chemical or Self-Sensitized Aerobic Photooxidation

“…There was no evidence of the ene-dione as would be expected due to a lack of oxygen in the system. Some evidence for the ene-yne (Z)-1,4-diphenylbut-1-en-3-yne 53 was observed in the 1 H NMR spectrum and the mass spectrum (m/z 205.1) of the photolysis products obtained under argon. The formation of a similar eneyne was reported by Barton and co-workers for 2-phenyltellurophene.…”

Copper(I) Hydroxyapatite Catalyzed Sonogashira Reaction of Alkynes with Styrenyl Bromides. Reaction of cis-Styrenyl Bromides Forming Unsymmetric Diynes

“…Recently, we demonstrated the application of hydroxyapatite-supported Pd(II) catalyst for coupling of diiodoalkenes and conjugated alkenes and hydroxyapatite-supported Cu(I)-catalyzed cyanation of styrenyl bromides . This encouraged us to explore the application of hydroxyapatite-supported Cu(I) catalyst for Sonogashira reaction of terminal alkynes and styrenyl halides with particular interest on coupling of both stereoisomers of styrenyl halides, as in previous reports, only trans -vinyl halides have been subjected to the reaction, and we did not find any general Sonogashira reaction with cis -vinyl halides except one example where cis -styrenyl bromide on reaction with phenyl acetylene catalyzed by CuI in presence of K 3 PO 4 produced the corresponding cis -1,3-enyne in 27% yield . We report here our results of Sonogashira coupling of terminal alkynes with trans - as well as cis -styrenyl bromides catalyzed by hydroxyapatite-supported Cu(I) [Cu (I)-Hap] (Scheme ).…”

“…The difficulty in the preparation of organometallic alkene restricts their uses. A recently developed straightforward approach involving Sonogashira coupling of vinyl halides and terminal alkynes catalyzed by Cu and Pd deserves special mention …”

De novo synthesis of functionalized 1,3-enynes and extended conjugated molecular systems

“…IR (lm): 3056, 2923, 1899, 1581, 1490, 1405, 1093 8e. 18 Yellow solid (0.084 g, 82%); m.p. 158-160 C, R f ¼ 0.56 (hexane).…”

“…, 776 cm À1 . HRMS (EI) calcd for C 10 H 7 Br 3 [M + ] 363.8098; found 363.8090.2a 18. Pale yellow solid (0.069 g, 84%); m.p.…”