A mild and efficient palladium-catalyzed homocoupling of lithium alkynyltriisopropoxyborates: a new route to synthesis of 1,3-diynes
作者:Chang Ho Oh、V.Raghava Reddy
DOI:10.1016/j.tetlet.2004.05.033
日期:2004.6
Lithium alkynyltriisopropoxyborates were homocoupled in the presence of palladium acetate and DPEPhos. This protocol allows a new efficient route to synthesis of 1,3-diynes under very mild conditions.
Nickel-Catalyzed [3 + 2 + 2] Cycloaddition of Ethyl Cyclopropylideneacetate and Heteroatom-Substituted Alkynes: Application to Selective Three-Component Reaction with 1,3-Diynes
Heteroatom-substituted alkynes such as ynol ethers and ynamines turned out to be decent substrates for the Ni-catalyzed [3 + 2 + 2] cocyclization of ethylcyclopropylideneacetate (1). The three-componentcocyclization of 1, 1,3-diynes, and heteroatom-substituted alkynes also proceeded selectively. The study provided an efficient method for the synthesis of heteroatom-substituted cycloheptadiene and related compounds
Regioselective [2 + 2 + 2] Cycloaddition of a Nickel−Benzyne Complex with 1,3-Diynes
作者:Kimberly R. Deaton、Mary S. Gin
DOI:10.1021/ol034720x
日期:2003.7.1
[GRAPHICS]Reactions of nickel(0)-benzyne complexes with a range of symmetrically substituted 1,3-diynes in the presence of triethylphosphine lead to the regioselective formation of 2,3-dialkynyl naphthalenes. The regioselectivity can be reversed when the diyne possesses substituents of high steric bulk, allowing selective formation of either symmetric dialkynyl naphthalene.
Cu-Catalyzed N<i>-</i>Alkynylation of Imidazoles, Benzimidazoles, Indazoles, and Pyrazoles Using PEG as Solvent Medium
作者:Glenn A. Burley、David L. Davies、Gerry A. Griffith、Michael Lee、Kuldip Singh
DOI:10.1021/jo902466f
日期:2010.2.5
A facile and efficient Cu(I)-catalyzed cross-coupling method is reported for the preparation of N-alkynyl or N-bromoalkenyl heteroarenes from bromoalkynes. Generally superior yields and functional group tolerance were obtained with microwave (MW) irradiation using imidazole, benzimidazole, pyrazole, and indazole substrates and poly(ethylene glycol) 400 (PEG400) as an additive. We speculate that PEG400 acts as both a Cu(I)-stabilizing ligand as well as a phase transfer solvent.