Rhodium-Catalyzed Oxidative Annulation of (2-Arylphenyl)boronic Acids with Alkynes: Selective Synthesis of Phenanthrene Derivatives was written by Nagata, Tomoya;Satoh, Tetsuya;Nishii, Yuji;Miura, Masahiro. And the article was included in Synlett in 2016.Computed Properties of C6H10O2 This article mentions the following:
A rhodium-catalyzed annulative coupling of (2-arylphenyl)boronic acids with alkynes has been developed for the facile construction of phenanthrene frameworks. The reaction proceeded without external bases, and dioxygen worked as a terminal oxidant. Deuterium-labeling experiments indicated the involvement of five-membered rhodacycle intermediates. In the experiment, the researchers used many compounds, for example, 1,4-Dimethoxy-2-butyne (cas: 16356-02-8Computed Properties of C6H10O2).
1,4-Dimethoxy-2-butyne (cas: 16356-02-8) belongs to ethers. Ether is less polar than esters, alcohols or amines because of the oxygen atom that is unable to participate in hydrogen bonding due to the presence of bulky alkyl groups on both sides of the oxygen atom. But ether is more polar than alkenes. Electron-deficient reagents are also stabilized by ethers. For example, borane (BH3) is a useful reagent for making alcohols. Pure borane exists as its dimer, diborane (B2H6), a toxic gas that is inconvenient and hazardous to use. Borane forms stable complexes with ethers, however, and it is often supplied and used as its liquid complex with tetrahydrofuran (THF).Computed Properties of C6H10O2
Ether – Wikipedia,
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