Aromatic Homologation by Non-Chelate-Assisted RhIII-Catalyzed C-H Functionalization of Arenes with Alkynes was written by Pham, Manh V.;Cramer, Nicolai. And the article was included in Angewandte Chemie, International Edition in 2014.Electric Literature of C6H10O2 This article mentions the following:
Larger condensed arenes are of interest owing to their electro- and photochem. properties. An efficient synthesis is the catalyzed aromatic annulation of a smaller arene with two alkyne mols. Besides difunctionalized starting materials, directed C-H functionalization can be used for such aromatic homologation. However, thus far the requirement of either pre-functionalized substrates or suitable directing groups were limiting this approach. Herein, we describe a rhodium(III)-catalyzed method allowing the use of completely unbiased arenes and internal alkynes. The reaction works best with copper(II) 2-ethylhexanoate and decabromodiphenyl ether as the oxidant combination. E.g., in presence of [(Cp*RhCl2)2], copper(II) 2-ethylhexanoate, and decabromodiphenyl ether, homologation of naphthalene with BuCCBu gave 60% anthracene derivative (I). This aromatic annulation tolerates a variety of functional groups and delivers homologated condensed arenes. Aside from simple benzenes, naphthalenes, and higher condensed arenes provide access to highly substituted and highly soluble acene structures having important electronic and photophys. properties. 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. Ethers are good solvents partly because they are not very reactive. Most ethers can be cleaved, however, by hydrobromic acid (HBr) to give alkyl bromides or by hydroiodic acid (HI) to give alkyl iodides. Autoxidation is the spontaneous oxidation of a compound in air. In the presence of oxygen, ethers slowly autoxidize to form hydroperoxides and dialkyl peroxides. If concentrated or heated, these peroxides may explode. To prevent such explosions, ethers should be obtained in small quantities, kept in tightly sealed containers, and used promptly.Electric Literature of C6H10O2
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem