Nucleophilic Addition to Acetylenes in Superbasic Catalytic Systems: XIV. Vinilation of Diols in a System CsF-NaOH

Abstract

A new catalytic system CsFNaOH was developed for the synthesis of mono-and divinyl ethers of alkanediols exceeding in efficiency KOH. The nucleophilic addition of diols to acetylene in the presence of this system occurs both at enhance pressure (without solvent, 140160°C) and atmospheric pressure (in DMSO medium, 100°C) of acetylene. Conditions were established of a selective preparation in a high yield of divinyl ethers from diols. * For communication XII see [1].Nucleophilic mono-and diaddition of diols to acetylene occurs under effect of strong bases (alkali metal hydroxides and alcoholates, superbasic system KOH DMSO etc.) at enhanced or atmospheric pressure of acetylene [210] and is accompanied as a rule by further transformations of the target mono-and divinyl ethers (acetalization, the rupture of CO bonds, elimination of a vinyl alcohol etc.) [213]. Therefore the search for new catalysts for the efficient and selective synthesis of mono-and divinyl ethers from diols remains an urgent problem. With this goal we have for the first time studied a reaction of acetylene with diols in the presence of a new catalytic system CsFNaOH [1, 14] whose efficiency is due apparently mainly to the formation in situ of anhydrous cesium hydroxide nanoparticles. The an-hydrous cesium hydroxide is known to be more active [15] but less available than KOH vinylation catalyst.By an example of a series of primary and secondary diols IaIg containing from 2 to 7 carbon atoms between the hydroxy groups we demonstrated that the main R = (CH 2 ) 2 (a), CH(CH 3 )CH(CH 3 ) (b), (CH 2 ) 3 (c), CH(CH 3 )(CH 2 ) 2 (d), (CH 2 ) 4 (e), CH(CH 3 )(CH 2 ) 2 CH(CH 3 ) (f), (CH 2 ) 7 (g). +252+&+ +&

Catalytic Reactions of Acetylene: A Feedstock for the Chemical Industry Revisited

“…The impressive aspect of the CsF/NaOH in DMSO system is not necessarily the observed increase in catalytic activity for vinylation of alcohols but the much better yields obtained in the vinylation of polyols with more than three carbon atoms between the OH groups. Thus, the vinylation of 1,4-butanediol using acetylene at atmospheric pressure and 100 °C in DMSO with 20 mol % CsF/NaOH affords the divinyl ether in 86% yield, whereas with 20 mol % KOH only a 10% yield of divinyl ether was obtained under the same conditions . In a different study it was shown that it is possible to catalyze this reaction with potassium alkoxides in aromatic solvents in the presence of crown ethers to solubilize the alkoxide.…”

“…Thus, the vinylation of 1,4-butanediol using acetylene at atmospheric pressure and 100 °C in DMSO with 20 mol % CsF/NaOH affords the divinyl ether in 86% yield, whereas with 20 mol % KOH only a 10% yield of divinyl ether was obtained under the same conditions. 118 In a different study it was shown that it is possible to catalyze this reaction with potassium alkoxides in aromatic solvents in the presence of crown ethers to solubilize the alkoxide. With this system better results than with potassium alkoxides in alcohols were achieved.…”