RhIII-catalyzed dual directing group assisted sterically hindered C-H bond activation: a unique route to meta and ortho substituted benzofurans was written by Yeh, Chien-Hung;Chen, Wei-Chen;Gandeepan, Parthasarathy;Hong, Ya-Chun;Shih, Cheng-Hung;Cheng, Chien-Hong. And the article was included in Organic & Biomolecular Chemistry in 2014.Safety of 1,4-Dimethoxy-2-butyne This article mentions the following:
A new strategy for the synthesis of highly substituted benzofurans, e.g., I (X-rays single crystal structure shown), from meta-substituted hydroxybenzenes and alkynes via a rhodium(III)-catalyzed activation of a sterically hindered C-H bond is demonstrated. A possible mechanism involving dual directing group assisted ortho C-H bond activation is proposed. In the experiment, the researchers used many compounds, for example, 1,4-Dimethoxy-2-butyne (cas: 16356-02-8Safety of 1,4-Dimethoxy-2-butyne).
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. At room temperature, ethers are pleasant-smelling colourless liquids. Relative to alcohols, ethers are generally less dense, are less soluble in water, and have lower boiling points. They are relatively unreactive, and as a result they are useful as solvents for fats, oils, waxes, perfumes, resins, dyes, gums, and hydrocarbons. Vapours of certain ethers are used as insecticides, miticides, and fumigants for soil.Safety of 1,4-Dimethoxy-2-butyne
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem