Formic acid; Internal aromatic alkynes; Palladium catalyst; Selective reduction; Transfer hydrogenation


Inorganic Chemistry | Organic Chemistry | Physical Sciences and Mathematics


An efficient and straightforward palladium acetylacetonate-catalyzed hydrogen transfer of 4'- (phenylethynyl)acetophenone was developed in this study. Formic Acid was found to be the best hydrogen source in this catalytic system in the presence of triethylamine. Excellent conversions and selectivity were obtained in reducing the starting internal aromatic alkyne to either (E)-1-(4- styrylphenyl)ethanone or an interesting cyclic product, 1-(phenanthrene-3-yl)ethenone, over the ketone functional group present. Over-reduction was rarely seen. The reaction conditions were optimized in terms of the choice of the palladium catalyst, temperature, solvent, and the H-donor/base combination. Using this catalytic system, a one-step synthetic pathway of the hindered cyclic ketone was afforded in excellent yields.

Author ORCID Identifier

Suzanne Chayya https://orcid.org/0000-0002-2375-8135

Akram Hijazi https://orcid.org/0000-0003-4984-8531

Anis Daou https://orcid.org/0000-0001-8495-3076

Ali Alaaeddine https://orcid.org/0000-0001-5188-6655

Mohamad Sakr https://orcid.org/0000-0001-5024-1388

Ghassan Younes https://orcid.org/0000-0001-6927-3523

Mohammad El-Dakdouki https://orcid.org/0000-0003-0679-2267





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