870010-35-8Relevant academic research and scientific papers
Gold-Catalyzed Domino Synthesis of Functionalized Benzofurans and Tetracyclic Isochromans via Formal Carboalkoxylation
Obata, Tomoyuki,Suzuki, Sho,Nakagawa, Asuka,Kajihara, Ryota,Noguchi, Keiichi,Saito, Akio
supporting information, p. 4136 - 4139 (2016/08/30)
A domino synthesis of benzofurans with the modification of side chains from α-alkoxyalkyl o-alkynylaryl ethers (n = 0) and electron-rich arenes has been developed. In the present domino reaction, which would proceed via the α-alkoxyalkylation of arenes with an intermediate in the migratory cycloisomerization of o-alkynylaryl ethers followed by the nucleophilic addition of benzofurans to benzyl ethers, a cationic Au(III) catalyst activates the C-C π bond and the C-O σ bond. The present method could be extended to Au(I)-catalyzed domino synthesis of tetracyclic isochromans from α-alkoxyalkyl (o-alkynylaryl)methyl ethers (n = 1) and aryl methoxymethyl ethers.
Gold-catalyzed cyclizations of (o-alkynyl)phenoxyacrylates with external nucleophiles: Regio-and stereoselective synthesis of functionalized benzo[b]oxepines
Liu, Jun,Liu, Yuanhong
supporting information, p. 4742 - 4745,4 (2020/09/16)
A catalytic approach to benzo[b]oxepines with high stereoselectivity by Au-catalyzed cyclization of (o-alkynyl)phenoxyacrylates with various nucleophiles under mild reaction conditions has been developed. Notably, the use of vinyl ether instead of alcohol could afford the same benzoxepines. The reaction may proceed by Au-catalyzed oligomerization of vinyl ether to release the alcohol, which then reacts with (o-alkynyl)phenoxyacrylates to furnish the benzoxepines.
Heterocycles by PtCl2-catalyzed intramolecular carboalkoxylation or carboamination of alkynes
Fuerstner, Alois,Davies, Paul W.
, p. 15024 - 15025 (2007/10/03)
PtCl2 constitutes a convenient catalyst for intramolecular hydroalkoxylation, carboalkoxylation, hydroamination, and carboamination reactions of alkynes, effecting the formation of substituted benzo[b]furan, indole-, and isochromene-1-one derivatives, respectively. This procedure allows for the transfer of (substituted) allyl, methoxymethyl (MOM), benzyloxymethyl (BOM), and (trimethylsilyl)ethoxymethyl (SEM) groups from oxygen to carbon and is compatible with functional groups that are susceptible to oxidative insertion of low valent metal species previously used for similar purposes. Although some of the reactions can even be carried out in air, the rates are significantly increased when conducted under an atmosphere of CO. A mechanistic rationale is proposed, implying activation of the alkyne by the carbophilic Pt(2+) template as the primary step of the catalytic cycle. Copyright
