The metal-free oxidative alkene methylation/alkynylation of 1,4-enyn-3-ols with an organic peroxide as the methyl source has been developed, which provides straightforward and practical access to the challenging quaternary-carbon-containing but-3-yn-1-ones. The method is reasoned to go through methylation of functional alkenes utilizing dicumyl peroxide as the methylating reagent and subsequent intermolecular
Carbonylation of organic halides in the presence of terminal acetylenes; novel acetylenic ketone synthesis
作者:Toshiaki Kobayashi、Masato Tanaka
DOI:10.1039/c39810000333
日期:——
Aryl, heterocyclic, and vinylic halides react with carbon monoxide and terminalacetylenes at 120 °C or below and 80 atm or below in the presence of triethyl-amine and a catalytic amount of a palladium (II) complex to form acetylenicketones in 46·7–92·9% yield.
An effective phosphine-catalyzed protocol has been established for the syntheses of 1,3-diketones and nitriles from alkynones with oximes as hydroxide surrogates. This method features the use of a phosphine catalyst, compatibility with various functional groups and ambient temperature, which makes this approach very practical. A plausible mechanism was proposed.
The first palladium-catalyzed Sonogashira coupling of amides has been developed, which proceeds via a selective cleavage of the N-acylsaccharin C–N bond. The protocol is mild, highly functional group tolerant and can be efficiently employed in the synthesis of a broad array of ynones in 48–98% yields under low catalyst loading and Cu-free conditions.
We developed a facile and practical synthesis of various alkynyl Z-ketimines, which can be used as a synthetic equivalent of alkyl ketimines. The obtained alkynyl Z-ketimines could be successfully applied in enantioselective Mannich reaction and conjugate addition catalyzed by a chiral amine with an acid functionality.