Hydroboration of substituted alkynes using a solid polymeric carboxylic acid catalyst was written by Hoyt, Caroline B.;Sarazen, Michele L.;Jones, Christopher W.. And the article was included in Journal of Catalysis in 2019.Safety of 1,4-Dimethoxy-2-butyne This article mentions the following:
A polymer-supported benzoic acid catalyst for the hydroboration of substituted alkynes with pinacolborane is reported. The robustness of the heterogenous catalyst is demonstrated through catalyst recycle, with comparable reactivity to the homogeneous catalyst. A mechanistic investigation that includes determination of a reaction rate law, 1H and 11B NMR studies, as well elucidation of the H/D kinetic isotope effect is used to identify the pathway through which product formation occurs. The polymer support provided a recoverable handle, with the active sites in close proximity to promote a two-site reaction pathway with the identification of key boryl species through 11B NMR. The activated alkynyl species is converted through a concerted hydroboration mechanism, supported by inverse KIE values, releasing product and regenerating the active site. Kinetic studies, where initial rates are proportional to the concentration of both the pinacolborane and the catalyst, but become inhibited by the alkyne at higher concentrations, suggest that the catalytic cycle can be described by a two-site rate expression with alkyne-derived surface species present during catalysis. 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. 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.Safety of 1,4-Dimethoxy-2-butyne
Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem