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Base‐Catalyzed Hydration of Silicon‐Containing Activated Alkynes: The Effect of Substituents at the Triple Bond
Author(s) -
Mareev Alexander V.,
Andreev Mikhail V.,
Ushakov Igor A.
Publication year - 2020
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.202002410
Subject(s) - dabco , chemistry , catalysis , octane , trimethylsilyl , base (topology) , pyran , metal , medicinal chemistry , acetylene , triple bond , polymer chemistry , organic chemistry , double bond , mathematical analysis , mathematics
Metal‐catalyzed hydration of alkynes is rapidly developing research direction in organic synthesis. However, base‐catalyzed hydration of activated acetylenes remains much less studied. In contrast to the metal‐catalyzed reactions leading to carbonyl compounds, base‐catalyzed hydration gives vinyl ethers of different structure or cyclic products depending on the nature of substituents. So, it is found that 1,4‐diazabicyclo [2.2.2]octane (DABCO)‐catalyzed hydration of trimethylsilylated electron‐deficient alkynes of general formula Me 3 SiC≡CCOX (X=Ph, NR 1 R 2 , OEt) proceeds at room temperature to afford push‐pull divinyl ethers in 56–94 % yields, while 4‐trimethylsilyl‐3‐butyne‐2‐one (X=Me) reacts non‐selectively delivering both symmetrical and unsymmetrical divinyl ethers (dimerization products). Contrary to ketones, amides and esters, 3‐trimethylsilylpropynal gives under the same conditions 4 H ‐pyran, as we shown earlier.