Cobalt-Catalyzed Formal [4+2] Cycloaddition of α,α’-Dichloro-ortho-Xylenes with Alkynes was written by Komeyama, Kimihiro;Okamoto, Yuji;Takaki, Ken. And the article was included in Angewandte Chemie, International Edition in 2014.Electric Literature of C6H10O2 This article mentions the following:
A formal [4+2] cycloaddition of α,α’-dichloro-ortho-xylenes with various alkynes has been developed using a low-valent cobalt catalyst. The transformation has a wide substrate scope and high functional-group tolerance and led to 1,4-dihydronaphthalenes. The formed cycloadducts were easily aromatized with MnO2 under air. A mechanistic investigation suggests that the transformation proceeds through a benzyl cobaltation of alkyne, not the classical Diels-Alder reaction of ortho-quinodimethanes. This methodol. provides a straightforward and streamlined access to linearly expanded π-conjugated aromatics In the experiment, the researchers used many compounds, for example, 1,4-Dimethoxy-2-butyne (cas: 16356-02-8Electric Literature of C6H10O2).
1,4-Dimethoxy-2-butyne (cas: 16356-02-8) belongs to ethers. Of all the functional groups, ethers are the least reactive ones. Ether bonds are quite stable towards bases, oxidizing agents and reducing agents. Ethyl ether is an excellent solvent for extractions and for a wide variety of chemical reactions. It is also used as a volatile starting fluid for diesel engines and gasoline engines in cold weather. Dimethyl ether is used as a spray propellant and refrigerant. Methyl t-butyl ether (MTBE) is a gasoline additive that boosts the octane number and reduces the amount of nitrogen-oxide pollutants in the exhaust. The ethers of ethylene glycol are used as solvents and plasticizers.Electric Literature of C6H10O2
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem