Gatto, Mattia et al. published their research in ACS Catalysis in 2016 | CAS: 16356-02-8

1,4-Dimethoxy-2-butyne (cas: 16356-02-8) belongs to ethers. Relative to alcohols, ethers are generally less dense, are less soluble in water, and have lower boiling points. They are relatively unreactive. 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).SDS of cas: 16356-02-8

Solvent-, Silver-, and Acid-Free NHC-Au-X Catalyzed Hydration of Alkynes. The Pivotal Role of the Counterion was written by Gatto, Mattia;Belanzoni, Paola;Belpassi, Leonardo;Biasiolo, Luca;DelZotto, Alessandro;Tarantelli, Francesco;Zuccaccia, Daniele. And the article was included in ACS Catalysis in 2016.SDS of cas: 16356-02-8 This article mentions the following:

NHC-Au-X (NHC = 1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene, X– = BArF–, BF4–, SbF6–, OTf–, NTf2–, ClO4–, OTs–, TFA–) catalysts were tested in the hydration of alkynes. A complete rationalization of the counterion effect enabled us to develop a highly efficient methodol. under solvent-, silver-, and acid-free conditions. Thus, it was possible to use room or mild (60 °C) temperature and to reduce the catalyst loading up to 0.01 mol % with respect to the substrate, leading to high TON (104) and TOF (103 h-1) values. The favorable catalytic conditions allowed us to reach very low E factor (0.03-0.06) and high EMY (94-97) values. Finally, the absence of solvent permits easy separation of the liquid product from solid catalyst and ionic additives by distillation, giving products with high purity that are uncontaminated by metals. This opens the way to catalyst recycling (up to four times) without loss of activity. The overall catalytic and kinetic evidence, supported by computational results, confirms that the anion plays a crucial role in all steps of the reaction mechanism: pre-equilibrium, nucleophilic attack, and protodeauration. As a matter of fact, only the two complexes bearing OTf– and NTf2– counterions showed catalytic activity; all others are completely inactive. Protodeauration is the rate-determining step under these aprotic and apolar conditions, and in calculations, the first anion-mediated proton transfer takes place easily in one step, leading to a gold-enol complex. Different pathways were computationally explored for the conversion of gold-enol to ketone product by modeling different exptl. conditions. In the experiment, the researchers used many compounds, for example, 1,4-Dimethoxy-2-butyne (cas: 16356-02-8SDS of cas: 16356-02-8).

1,4-Dimethoxy-2-butyne (cas: 16356-02-8) belongs to ethers. Relative to alcohols, ethers are generally less dense, are less soluble in water, and have lower boiling points. They are relatively unreactive. 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).SDS of cas: 16356-02-8

Referemce:
Ether – Wikipedia,
Ether | (C2H5)2O – PubChem