Ruthenium-Catalyzed Transfer Oxygenative Cyclization of α,ω-Diynes: Unprecedented [2 + 2 + 1] Route to Bicyclic Furans via Ruthenacyclopentatriene
摘要:
A novel oxygen-atom-transfer process enables the catalytic [2 + 2 + 1] synthesis of bicyclic furans from alpha,omega-diynes with DMSO. [CpRu(AN)(3)]PF6 catalyzed the transfer oxygenative cyclization of diynes with aryl terminal groups, while those of diynes with alkyl terminal groups were effectively promoted by the corresponding Cp* complex. A mechanism for bicyclic furan formation via a ruthenacyclopentatriene was proposed on the basis of both experimental and theoretical studies.
Strategies towards potent trypanocidal drugs: Application of Rh-catalyzed [2 + 2 + 2] cycloadditions, sulfonyl phthalide annulation and nitroalkene reactions for the synthesis of substituted quinones and their evaluation against Trypanosoma cruzi
作者:James M. Wood、Nishikant S. Satam、Renata G. Almeida、Vinicius S. Cristani、Dênis P. de Lima、Luiza Dantas-Pereira、Kelly Salomão、Rubem F.S. Menna-Barreto、Irishi N.N. Namboothiri、John F. Bower、Eufrânio N. da Silva Júnior
DOI:10.1016/j.bmc.2020.115565
日期:2020.8
Rhodium-catalyzed [2 + 2 + 2] cycloadditions, sulfonyl phthalideannulations and nitroalkene reactions have been employed for the synthesis of 56 quinone-based compounds. These were evaluated against Trypanosoma cruzi, the parasite that causes Chagas disease. The reactions described here are part of a program that aims to utilize modern, versatile and efficient synthetic methods for the one or two
The solvent‐ and ligand‐free [2+2+2] ruthenium‐promoted cycloaddition of α,ω‐diynes and alkynes provides a facile and efficient strategy for the synthesis of substituted benzene‐derived systems. The search for the optimal reaction conditions revealed the unprecedented catalytic activity of ruthenium trichloride for benzannulation reactions and this atom‐economical process allowed the synthesis of fused
Synthesis of Siloles via Rhodium-Catalyzed Cyclization of Alkynes and Diynes with Hexamethyldisilane
作者:Takanori Matsuda、Yuya Suda、Yosuke Fujisaki
DOI:10.1055/s-0030-1259914
日期:2011.4
A rhodium-catalyzed silylative cyclization of alkynes and 1,6-diynes with hexamethyldisilane is described. These reactions enable the synthesis of densely substituted silole derivatives through the use of a rhodium(I)-norborna-2,5-diene complex as a catalyst.
Rh-Catalyzed [2 + 2 + 2] Cycloadditions with Benzoquinones: De Novo Access to Naphthoquinones for Lignan and Type II Polyketide Synthesis
作者:James M. Wood、Eufrânio N. da Silva Júnior、John F. Bower
DOI:10.1021/acs.orglett.9b04266
日期:2020.1.3
The first examples of Rh-catalyzed [2 + 2 + 2] cycloadditions between diynes and benzoquinones are described. The method enables de novo and step-economical access to challenging naphthoquinones that are of relevance to lignan and type II polyketide synthesis. The value of the chemistry is demonstrated by a short total synthesis of justicidone.
Rhodium(III)-Catalyzed [2+2+2] Cyclotrimerization of Diynes with Maleic Anhydrides as Alkyne Equivalents
作者:Takanori Matsuda、Kentaro Suzuki
DOI:10.1002/ejoc.201500252
日期:2015.5
anhydrides function as syntheticequivalents of alkynes in a rhodium(III)-catalyzed reaction with 1,6-diynes to achieve a formal [2+2+2] cyclotrimerization. This approach is useful for reactions involving alkynes with low boiling points or severe ring strain. Hard-to-access [2+2+2] cycloadducts are available through this new cycloaddition strategy by employing easy-to-handle alkyne equivalents.